Hematology

A routine blood test may pack a bigger punch than previously suspected, suggests a recent analysis of over 3 million Canadian patient records.

A finding of thrombocytosis (platelet count >450 x 109/L) was associated with a greatly increased risk for some cancers up to 5 years later.

Overall, a high platelet count increased by 2.7 times the odds of receiving a solid-tumor cancer diagnosis within 2 years (95% confidence interval, 2.6-2.8).

The cancers most likely to be associated with unexpected thrombocytosis were those notorious for late-stage diagnosis due to a lack of early symptoms.

The risk was highest (23.3 times) for ovarian cancer. The risk was 3.8 times higher for pancreatic cancer and 3.5 times higher for cervical cancer.

Lung cancer was 4.4 times more likely within 2 years among patients with thrombocytosis compared to patients with normal platelet counts.

Conversely, breast, prostate, and thyroid cancers were not linked to the finding of thrombocytosis.

The study results were published online in JAMA Network Open on Aug. 12).

One of the authors of the article, Stephen A. Narod, MD, director of the Familial Breast Cancer Research Unit at the Women’s College Research Institute, Toronto, said the results were not unexpected but “very striking.”

“I had a hunch we were going to see this because I’ve seen this in other databases,” said Dr. Narod. “I think what struck me about it was how ubiquitous it was.”

Dr. Narod urged physicians, especially those in primary care, to take note: “If the platelets are high, I would certainly have a concern about lung cancer, colon cancer, and ovarian cancer.”

Dr. Narod and coauthor Vasily Giannakeas, a PhD candidate, pointed out that in their analysis that they were unable to single out cases in which a blood test was performed because the patient complained of symptoms that are associated with cancer. In those cases, thrombocytosis may have been diagnostic, rather than a lifesaving serendipitous finding.

Similar findings were reported recently from the United Kingdom.

A study by Sarah Bailey, PhD, MPH, and colleagues that was published last year in the British Journal of General Practice also found a connection between cancer incidence and platelet count. Dr. Bailey is a senior research fellow at the University of Exeter, England.

However, unlike in the Canadian study, the team led by Dr. Bailey was able to distinguish those patients for whom there were alarm symptoms for cancer. Dr. Bailey and colleagues found that two-thirds of men older than 65 had “no recorded alarm features of cancer in the 21 days before their index platelet count.”

Although this suggests that a routine finding of thrombocytosis could uncover unsuspected cancers, Dr. Bailey is cautious about hailing platelet counts as a new cancer-screening tool.

In emailed comments, Dr. Bailey said, “The crucial part of our study is that it was conducted with patients who were ill enough to see their GP [general practitioner]. Opportunistic measurement in patients who are asymptomatic would be quite a different thing. We would have to study the platelet count and subsequent cancers in asymptomatic patients to know if that was worth doing.”

Perhaps most helpfully, the U.K. study showed that cancer risk was increased even among some patients with normal platelet counts. For example, for men aged 60 and older, lung cancer was 4.7 times more likely among those with high-normal counts (≥326 x 109/L).

Because of this somewhat alarming finding, Dr. Bailey suggested moving away from a focus on absolute values. Rising platelet counts might be more clinically useful, she said.

“Physicians should be on the lookout for any unexplained increase in an individual’s platelet count, irrespective of whether the increased value is over or under the local threshold that is applied to define thrombocytosis,” concluded Dr. Bailey.

Dr. Narod has disclosed no relevant financial relationships. Dr. Bailey is a research fellow of the CanTest Collaborative.

A version of this article first appeared on Medscape.com.

A routine blood test may pack a bigger punch than previously suspected, suggests a recent analysis of over 3 million Canadian patient records.

A finding of thrombocytosis (platelet count >450 x 109/L) was associated with a greatly increased risk for some cancers up to 5 years later.

Overall, a high platelet count increased by 2.7 times the odds of receiving a solid-tumor cancer diagnosis within 2 years (95% confidence interval, 2.6-2.8).

The cancers most likely to be associated with unexpected thrombocytosis were those notorious for late-stage diagnosis due to a lack of early symptoms.

The risk was highest (23.3 times) for ovarian cancer. The risk was 3.8 times higher for pancreatic cancer and 3.5 times higher for cervical cancer.

Lung cancer was 4.4 times more likely within 2 years among patients with thrombocytosis compared to patients with normal platelet counts.

Conversely, breast, prostate, and thyroid cancers were not linked to the finding of thrombocytosis.

The study results were published online in JAMA Network Open on Aug. 12).

One of the authors of the article, Stephen A. Narod, MD, director of the Familial Breast Cancer Research Unit at the Women’s College Research Institute, Toronto, said the results were not unexpected but “very striking.”

“I had a hunch we were going to see this because I’ve seen this in other databases,” said Dr. Narod. “I think what struck me about it was how ubiquitous it was.”

Dr. Narod urged physicians, especially those in primary care, to take note: “If the platelets are high, I would certainly have a concern about lung cancer, colon cancer, and ovarian cancer.”

Dr. Narod and coauthor Vasily Giannakeas, a PhD candidate, pointed out that in their analysis that they were unable to single out cases in which a blood test was performed because the patient complained of symptoms that are associated with cancer. In those cases, thrombocytosis may have been diagnostic, rather than a lifesaving serendipitous finding.

Similar findings were reported recently from the United Kingdom.

A study by Sarah Bailey, PhD, MPH, and colleagues that was published last year in the British Journal of General Practice also found a connection between cancer incidence and platelet count. Dr. Bailey is a senior research fellow at the University of Exeter, England.

However, unlike in the Canadian study, the team led by Dr. Bailey was able to distinguish those patients for whom there were alarm symptoms for cancer. Dr. Bailey and colleagues found that two-thirds of men older than 65 had “no recorded alarm features of cancer in the 21 days before their index platelet count.”

Although this suggests that a routine finding of thrombocytosis could uncover unsuspected cancers, Dr. Bailey is cautious about hailing platelet counts as a new cancer-screening tool.

In emailed comments, Dr. Bailey said, “The crucial part of our study is that it was conducted with patients who were ill enough to see their GP [general practitioner]. Opportunistic measurement in patients who are asymptomatic would be quite a different thing. We would have to study the platelet count and subsequent cancers in asymptomatic patients to know if that was worth doing.”

Perhaps most helpfully, the U.K. study showed that cancer risk was increased even among some patients with normal platelet counts. For example, for men aged 60 and older, lung cancer was 4.7 times more likely among those with high-normal counts (≥326 x 109/L).

Because of this somewhat alarming finding, Dr. Bailey suggested moving away from a focus on absolute values. Rising platelet counts might be more clinically useful, she said.

“Physicians should be on the lookout for any unexplained increase in an individual’s platelet count, irrespective of whether the increased value is over or under the local threshold that is applied to define thrombocytosis,” concluded Dr. Bailey.

Dr. Narod has disclosed no relevant financial relationships. Dr. Bailey is a research fellow of the CanTest Collaborative.

A version of this article first appeared on Medscape.com.

A routine blood test may pack a bigger punch than previously suspected, suggests a recent analysis of over 3 million Canadian patient records.

A finding of thrombocytosis (platelet count >450 x 109/L) was associated with a greatly increased risk for some cancers up to 5 years later.

Overall, a high platelet count increased by 2.7 times the odds of receiving a solid-tumor cancer diagnosis within 2 years (95% confidence interval, 2.6-2.8).

The cancers most likely to be associated with unexpected thrombocytosis were those notorious for late-stage diagnosis due to a lack of early symptoms.

The risk was highest (23.3 times) for ovarian cancer. The risk was 3.8 times higher for pancreatic cancer and 3.5 times higher for cervical cancer.

Lung cancer was 4.4 times more likely within 2 years among patients with thrombocytosis compared to patients with normal platelet counts.

Conversely, breast, prostate, and thyroid cancers were not linked to the finding of thrombocytosis.

The study results were published online in JAMA Network Open on Aug. 12).

One of the authors of the article, Stephen A. Narod, MD, director of the Familial Breast Cancer Research Unit at the Women’s College Research Institute, Toronto, said the results were not unexpected but “very striking.”

“I had a hunch we were going to see this because I’ve seen this in other databases,” said Dr. Narod. “I think what struck me about it was how ubiquitous it was.”

Dr. Narod urged physicians, especially those in primary care, to take note: “If the platelets are high, I would certainly have a concern about lung cancer, colon cancer, and ovarian cancer.”

Dr. Narod and coauthor Vasily Giannakeas, a PhD candidate, pointed out that in their analysis that they were unable to single out cases in which a blood test was performed because the patient complained of symptoms that are associated with cancer. In those cases, thrombocytosis may have been diagnostic, rather than a lifesaving serendipitous finding.

Similar findings were reported recently from the United Kingdom.

A study by Sarah Bailey, PhD, MPH, and colleagues that was published last year in the British Journal of General Practice also found a connection between cancer incidence and platelet count. Dr. Bailey is a senior research fellow at the University of Exeter, England.

However, unlike in the Canadian study, the team led by Dr. Bailey was able to distinguish those patients for whom there were alarm symptoms for cancer. Dr. Bailey and colleagues found that two-thirds of men older than 65 had “no recorded alarm features of cancer in the 21 days before their index platelet count.”

Although this suggests that a routine finding of thrombocytosis could uncover unsuspected cancers, Dr. Bailey is cautious about hailing platelet counts as a new cancer-screening tool.

In emailed comments, Dr. Bailey said, “The crucial part of our study is that it was conducted with patients who were ill enough to see their GP [general practitioner]. Opportunistic measurement in patients who are asymptomatic would be quite a different thing. We would have to study the platelet count and subsequent cancers in asymptomatic patients to know if that was worth doing.”

Perhaps most helpfully, the U.K. study showed that cancer risk was increased even among some patients with normal platelet counts. For example, for men aged 60 and older, lung cancer was 4.7 times more likely among those with high-normal counts (≥326 x 109/L).

Because of this somewhat alarming finding, Dr. Bailey suggested moving away from a focus on absolute values. Rising platelet counts might be more clinically useful, she said.

“Physicians should be on the lookout for any unexplained increase in an individual’s platelet count, irrespective of whether the increased value is over or under the local threshold that is applied to define thrombocytosis,” concluded Dr. Bailey.

Dr. Narod has disclosed no relevant financial relationships. Dr. Bailey is a research fellow of the CanTest Collaborative.

A version of this article first appeared on Medscape.com.

The U.S. Department of Veteran Affairs (VA) has been unable to provide genetic counseling to veterans at the same level as the civilian community, and other gaps exist, a genetic counselor told oncologist and hematologist colleagues. The good news is that telemedicine is turning out to be a valuable and proven way to reach veterans who need this kind of care, she said, although certain patients are being left behind.

“To me, telehealth is no doubt the way to go. But it is really important that we continue to look into these disparities, what's causing them, and how we can find a path forward,” said

Deborah Hartzfeld, MS, CGC, of the Genomic Medicine Service based in Salt Lake City, Utah. She spoke in a presentation at the 2021 annual meeting of the Association of VA Hematology/Oncology (AVAHO) that was held virtually and in person in Denver, Colorado, from September 24 to September 26, 2021.

As Harzfeld explained, the genetic counselor workforce is expanding along with the number of indications for genetic testing, especially in cancer, “where the need for germline genetic testing for inherited cancer genes becomes broader every year.”

Genetic counselors are a homogenous group, she said, as revealed by a 2021 survey of most of the nation’s 5,629 certified generic counselors. The North American survey, by the National Society of Genetic Counselors, found that 94% of respondents identified themselves as female, and 90% were white/non-Hispanic.  

The survey report also noted that “the genetic counseling profession has grown by over 100% in the last 10 years and is expected to grow another 100% over the next 10 years. By 2025 there should be nearly 7,500 certified genetic counselors, and by 2030 there are likely to be over 10,000.”

Genetic counseling within the VA has also grown rapidly. In 2010, Harzfeld said, about 737 veterans were referred for the service. In 2020, the number was about 10,000, with about half referred for personal or family history of cancer.

The VA has 18 genetic counselors, not all of whom are actively seeing patients or working full time, she said. “Per the National Society of Genetic Counselors, there's one clinical genetic counselor per 100,000 people in the general population,” she said. “It's one for about 474,000 in the VA.”

Wait times for genetic counseling within the VA exceed Mission Act standards outside of urgent referrals in matters such as surgical or medical management, she said. “We usually see those patients within a week, but other folks have to wait or are referred into the community. It remains unclear how many of our patients could access care easily in the community or what the wait times at any individual VA will be.”

Fortunately, she said, telemedicine has increased access to genetic counseling within the general population and the VA, Harzfeld said. “A recent systematic evidence review found providing genetic counseling via video or telephone is comparable to in-person care, it increases access and it's likely feasible and acceptable to major stakeholders. It's worth noting that the data in this evidence review was collected prior to COVID-19 when fewer programs were using telehealth.”

Genetic counseling works especially well via telehealth because counselors don’t perform physical examinations, she said. “Prior to COVID, service probably saw maybe 4 VVC [VA Video Connect] appointments per month for genetic counseling. Now, VVC makes up about 70% of our new patient encounters. About 25% are telephone and about 5% are clinical video telehealth where the veteran goes into their clinic to be seated in front of the machine.”

Research has suggested that non-White patients are 40 to 50% less likely to be referred to telehealth for genetic counseling vs. in-person encounters, she said, although women in general (including black women) are more likely to be referred.

Harzfeld highlighted several challenges facing genetic counseling in the VA. She notes that contracted laboratories aren’t “really set up to be experts in germline genetic testing, so they’re not as nimble, and their test catalogs are not most likely going to be as comprehensive enough for what is needed.” Also, she said, “test ordering can be quite burdensome.”

“We need to continue working with various partners to increase access and the ease of ordering genetic testing,” she said.

Hartzfeld reports no disclosures.

The U.S. Department of Veteran Affairs (VA) has been unable to provide genetic counseling to veterans at the same level as the civilian community, and other gaps exist, a genetic counselor told oncologist and hematologist colleagues. The good news is that telemedicine is turning out to be a valuable and proven way to reach veterans who need this kind of care, she said, although certain patients are being left behind.

“To me, telehealth is no doubt the way to go. But it is really important that we continue to look into these disparities, what's causing them, and how we can find a path forward,” said

Deborah Hartzfeld, MS, CGC, of the Genomic Medicine Service based in Salt Lake City, Utah. She spoke in a presentation at the 2021 annual meeting of the Association of VA Hematology/Oncology (AVAHO) that was held virtually and in person in Denver, Colorado, from September 24 to September 26, 2021.

As Harzfeld explained, the genetic counselor workforce is expanding along with the number of indications for genetic testing, especially in cancer, “where the need for germline genetic testing for inherited cancer genes becomes broader every year.”

Genetic counselors are a homogenous group, she said, as revealed by a 2021 survey of most of the nation’s 5,629 certified generic counselors. The North American survey, by the National Society of Genetic Counselors, found that 94% of respondents identified themselves as female, and 90% were white/non-Hispanic.  

The survey report also noted that “the genetic counseling profession has grown by over 100% in the last 10 years and is expected to grow another 100% over the next 10 years. By 2025 there should be nearly 7,500 certified genetic counselors, and by 2030 there are likely to be over 10,000.”

Genetic counseling within the VA has also grown rapidly. In 2010, Harzfeld said, about 737 veterans were referred for the service. In 2020, the number was about 10,000, with about half referred for personal or family history of cancer.

The VA has 18 genetic counselors, not all of whom are actively seeing patients or working full time, she said. “Per the National Society of Genetic Counselors, there's one clinical genetic counselor per 100,000 people in the general population,” she said. “It's one for about 474,000 in the VA.”

Wait times for genetic counseling within the VA exceed Mission Act standards outside of urgent referrals in matters such as surgical or medical management, she said. “We usually see those patients within a week, but other folks have to wait or are referred into the community. It remains unclear how many of our patients could access care easily in the community or what the wait times at any individual VA will be.”

Fortunately, she said, telemedicine has increased access to genetic counseling within the general population and the VA, Harzfeld said. “A recent systematic evidence review found providing genetic counseling via video or telephone is comparable to in-person care, it increases access and it's likely feasible and acceptable to major stakeholders. It's worth noting that the data in this evidence review was collected prior to COVID-19 when fewer programs were using telehealth.”

Genetic counseling works especially well via telehealth because counselors don’t perform physical examinations, she said. “Prior to COVID, service probably saw maybe 4 VVC [VA Video Connect] appointments per month for genetic counseling. Now, VVC makes up about 70% of our new patient encounters. About 25% are telephone and about 5% are clinical video telehealth where the veteran goes into their clinic to be seated in front of the machine.”

Research has suggested that non-White patients are 40 to 50% less likely to be referred to telehealth for genetic counseling vs. in-person encounters, she said, although women in general (including black women) are more likely to be referred.

Harzfeld highlighted several challenges facing genetic counseling in the VA. She notes that contracted laboratories aren’t “really set up to be experts in germline genetic testing, so they’re not as nimble, and their test catalogs are not most likely going to be as comprehensive enough for what is needed.” Also, she said, “test ordering can be quite burdensome.”

“We need to continue working with various partners to increase access and the ease of ordering genetic testing,” she said.

Hartzfeld reports no disclosures.

The U.S. Department of Veteran Affairs (VA) has been unable to provide genetic counseling to veterans at the same level as the civilian community, and other gaps exist, a genetic counselor told oncologist and hematologist colleagues. The good news is that telemedicine is turning out to be a valuable and proven way to reach veterans who need this kind of care, she said, although certain patients are being left behind.

“To me, telehealth is no doubt the way to go. But it is really important that we continue to look into these disparities, what's causing them, and how we can find a path forward,” said

Deborah Hartzfeld, MS, CGC, of the Genomic Medicine Service based in Salt Lake City, Utah. She spoke in a presentation at the 2021 annual meeting of the Association of VA Hematology/Oncology (AVAHO) that was held virtually and in person in Denver, Colorado, from September 24 to September 26, 2021.

As Harzfeld explained, the genetic counselor workforce is expanding along with the number of indications for genetic testing, especially in cancer, “where the need for germline genetic testing for inherited cancer genes becomes broader every year.”

Genetic counselors are a homogenous group, she said, as revealed by a 2021 survey of most of the nation’s 5,629 certified generic counselors. The North American survey, by the National Society of Genetic Counselors, found that 94% of respondents identified themselves as female, and 90% were white/non-Hispanic.  

The survey report also noted that “the genetic counseling profession has grown by over 100% in the last 10 years and is expected to grow another 100% over the next 10 years. By 2025 there should be nearly 7,500 certified genetic counselors, and by 2030 there are likely to be over 10,000.”

Genetic counseling within the VA has also grown rapidly. In 2010, Harzfeld said, about 737 veterans were referred for the service. In 2020, the number was about 10,000, with about half referred for personal or family history of cancer.

The VA has 18 genetic counselors, not all of whom are actively seeing patients or working full time, she said. “Per the National Society of Genetic Counselors, there's one clinical genetic counselor per 100,000 people in the general population,” she said. “It's one for about 474,000 in the VA.”

Wait times for genetic counseling within the VA exceed Mission Act standards outside of urgent referrals in matters such as surgical or medical management, she said. “We usually see those patients within a week, but other folks have to wait or are referred into the community. It remains unclear how many of our patients could access care easily in the community or what the wait times at any individual VA will be.”

Fortunately, she said, telemedicine has increased access to genetic counseling within the general population and the VA, Harzfeld said. “A recent systematic evidence review found providing genetic counseling via video or telephone is comparable to in-person care, it increases access and it's likely feasible and acceptable to major stakeholders. It's worth noting that the data in this evidence review was collected prior to COVID-19 when fewer programs were using telehealth.”

Genetic counseling works especially well via telehealth because counselors don’t perform physical examinations, she said. “Prior to COVID, service probably saw maybe 4 VVC [VA Video Connect] appointments per month for genetic counseling. Now, VVC makes up about 70% of our new patient encounters. About 25% are telephone and about 5% are clinical video telehealth where the veteran goes into their clinic to be seated in front of the machine.”

Research has suggested that non-White patients are 40 to 50% less likely to be referred to telehealth for genetic counseling vs. in-person encounters, she said, although women in general (including black women) are more likely to be referred.

Harzfeld highlighted several challenges facing genetic counseling in the VA. She notes that contracted laboratories aren’t “really set up to be experts in germline genetic testing, so they’re not as nimble, and their test catalogs are not most likely going to be as comprehensive enough for what is needed.” Also, she said, “test ordering can be quite burdensome.”

“We need to continue working with various partners to increase access and the ease of ordering genetic testing,” she said.

Hartzfeld reports no disclosures.

A new series of cases of cerebral venous sinus thrombosis (CVST) linked to the adenoviral vector COVID-19 vaccines has been reported, confirming the severity of the reaction and the associated high mortality rate.

The new series comes from an international registry of consecutive patients who experienced CVST within 28 days of COVID-19 vaccination between March 29 and June 18, 2021, from 81 hospitals in 19 countries.

The cases are described in an article published online on Sept. 28. in JAMA Neurology.

“This is a reliable description on the clinical condition of these patients with CVST associated with COVID-19 vaccination. It is striking that this a much worse condition than CVST not associated with COVID-19 vaccination, with a much higher rate of intracerebral hemorrhage and coma and a much higher mortality rate,” senior author Jonathan M. Coutinho, MD, Amsterdam University Medical Centers, told this news organization.

These data confirm the observations from an earlier U.K. cohort in which cases of cerebral venous thrombosis linked to COVID-19 vaccination occurred.

“This is the biggest series, and as an international series, it gives a broader perspective from a larger range of countries,” Dr. Coutinho said. “All the data together show that, although this side effect is rare, the consequences are very severe,” he added.

In the current study, the researchers regarded CVST as being linked to the vaccine if it was accompanied by thrombosis with thrombocytopenia syndrome (TTS), as evidenced by thrombosis and new-onset thrombocytopenia.

In the cohort of 116 patients with CVST after COVID-19 vaccination, 78 (67.2%) had thrombosis with TTS and were thus classified as having had a vaccine-related adverse event. These patients were frequently comatose at presentation (24%) and often had intracerebral hemorrhage (68%) and concomitant thromboembolism (36%); 47% died during hospitalization.

These patients were compared with the 38 patients in the same cohort who had CVST but in whom there was no indication of concomitant thrombosis and thrombocytopenia. The case patients were also compared with a control group of 207 patients with CVST who were included in a separate international registry before the COVID-19 pandemic.

Mortality rates were much higher among the patients deemed to have had a vaccine-related CVST. The in-hospital mortality rate was 47%, compared with 5% among the patients in the same cohort who did not have TTS and 3.9% among the prepandemic control group.

The mortality rate was even higher (61%) among patients in the TTS group for whom the diagnosis was made before the condition garnered attention in the scientific community. The mortality rate was 42% among patients diagnosed later.

Of the 78 patients in whom CVST and TTS occurred after COVID-19 vaccination in this cohort, 76 had received the AstraZeneca vaccine (in 75 patients, CVST and TTS occurred after the first vaccination; in one patient, they occurred after the second vaccination). One patient had received the Johnson & Johnson vaccine, and one had received the Pfizer vaccine.

“After more analysis, the case after the Pfizer vaccination is not believed to be caused by the vaccine,” Dr. Coutinho said. “In that case, the patient had a platelet count just below the lower limit and was taking an immunomodulator drug that is known to be associated with thrombocytopenia.”

For two patients who received the AstraZeneca vaccine, there was also an alternative explanation for the thrombocytopenia.

Dr. Coutinho also pointed out that the Johnson & Johnson vaccine has been used mainly in the United States, and these data were largely from other countries.

The median time from vaccination to CVST symptom onset was 9 days in the TTS group. The median platelet count at hospital admission among patients with postvaccination CVST-TTS was 45. Three patients presented with a normal platelet count and developed thrombocytopenia during admission; two patients presented with mild thrombocytopenia, 30 presented with moderate thrombocytopenia, and 43 presented with severe thrombocytopenia.

Antibodies against platelet factor 4 (PF4) were measured in 69 patients with TTS, of whom 63 (91%) tested positive (the one patient in whom TTS occurred after the patient received the Pfizer vaccine did not test positive). However, the researchers note that sensitivity varies among different PF4 ELISA tests. Findings of platelet activation assays were positive in all 36 tested patients.

In the TTS group, 52 patients (67%) received immunomodulation therapy, most often intravenous immunoglobulins (IVIG). Among patients treated with IVIG, the mortality rate was lower (28%).
 

Different from CVST linked to natural COVID-19 infection

Dr. Coutinho noted that CVST can occur in natural SARS-CoV-2 infection but that vaccine-associated CVST is very different.

“In natural COVID-19 infection, there is an increased risk of thrombosis, and some patients can get CVST as a part of this, but in these cases, this is not accompanied by thrombocytopenia. While the CVST in natural COVID-19 infection is also associated with a bad prognosis, this is more to do with the underlying disease. It is normally the very sick COVID patients who develop CVST, and these patients usually die from the underlying disease rather than the CVST itself,” he explained.

“Clinicians need to be aware of vaccine-related CVST, as it requires very specific and rapid treatment,” Dr. Coutinho stressed.

“Patients presenting with an extremely severe headache (unlike any headache they’ve had before) or with seizures or a focal deficit (weakness in arm or problems with speaking or vision) within 4 weeks of an adenovirus COVID-19 vaccination should ring alarm bells. It is important to do diagnostics quickly, with a platelet count the most important first step, and a rapid CT/MRI scan,” he said.

Other tests that should be conducted are D-dimer for thrombosis and the PF4 antibody test. But results for the PF4 antibody test can take days to come back, and clinicians shouldn’t wait for that, Dr. Coutinho notes.

“Specific treatment needs to be given immediately – with anticoagulation (preferably nonheparin) and immunomodulation with IVIG to stop the immune reaction. Platelets should not be given – that may seem counterintuitive in patients with a low platelet count, but giving platelets makes it worse,” he said.
 

Is there a geographic difference?

Dr. Coutinho pointed out that fewer cases of this vaccine-related CVST are being reported at the current time.

“We are not sure why this is the case. These adenovirus vaccines are not being used much now in Western countries, but our collaboration covers many less developed countries in South America and Asia, which are relying heavily on these vaccines. We are now shifting focus to these countries, but so far we have only seen a handful of cases from these areas,” he said.

He suggested that this may be because these countries started their vaccination programs later and are vaccinating their elderly (who are not so susceptible to this side effect) first, or it may be because of some environmental or genetic factor that has not yet been discovered.

“This is now an important research question – is the risk of vaccine-induced CVST the same in different countries or ethnicities? This could influence decisions on future vaccine strategies,” Dr. Coutinho said.

“So far, female sex is the strongest risk factor for vaccine-induced CVST. In our cohort, 81% of cases were in women. In addition, 95% were White, but that doesn’t allow us to conclude that this is a risk factor, as the majority of people who have been vaccinated are White. So, we have no clear insight into that yet,” he said.

In a comment for this news organization, the lead author of the previous U.K. report of a series of 70 cases of cerebral venous thrombosis linked to COVID-19 vaccination, Richard Perry, PhD, University College Hospital, London, described this new report as “an excellent study, with many of the same strengths and weaknesses as our study and has very similar results.”

Dr. Perry noted that the two studies used slightly different definitions of vaccine-induced thrombotic thrombocytopenia, but the cases reported appear to be very similar overall. “It is reassuring and gratifying to see that they have made such similar observations,” he said.

“And as they have drawn their cases from a broad range of countries whereas ours were all from the U.K., this provides evidence that the observations from both studies are reasonably generalizable,” he added.

Dr. Perry pointed out that this new report states that TTS occurred in one patient after the patient had received a second dose of the AstraZeneca vaccine. “I would like to know more about this case, because we didn’t see any cases after a second dose in our cohort,” he said.

Dr. Coutinho responded that he didn’t believe this was the first reported case after the second dose.

The study did not receive any specific funding. Dr. Coutinho has received grants paid to his institution from Boehringer Ingelheim and Bayer and payments paid to his institution for data safety monitoring board participation by Bayer.

A version of this article first appeared on Medscape.com.

A new series of cases of cerebral venous sinus thrombosis (CVST) linked to the adenoviral vector COVID-19 vaccines has been reported, confirming the severity of the reaction and the associated high mortality rate.

The new series comes from an international registry of consecutive patients who experienced CVST within 28 days of COVID-19 vaccination between March 29 and June 18, 2021, from 81 hospitals in 19 countries.

The cases are described in an article published online on Sept. 28. in JAMA Neurology.

“This is a reliable description on the clinical condition of these patients with CVST associated with COVID-19 vaccination. It is striking that this a much worse condition than CVST not associated with COVID-19 vaccination, with a much higher rate of intracerebral hemorrhage and coma and a much higher mortality rate,” senior author Jonathan M. Coutinho, MD, Amsterdam University Medical Centers, told this news organization.

These data confirm the observations from an earlier U.K. cohort in which cases of cerebral venous thrombosis linked to COVID-19 vaccination occurred.

“This is the biggest series, and as an international series, it gives a broader perspective from a larger range of countries,” Dr. Coutinho said. “All the data together show that, although this side effect is rare, the consequences are very severe,” he added.

In the current study, the researchers regarded CVST as being linked to the vaccine if it was accompanied by thrombosis with thrombocytopenia syndrome (TTS), as evidenced by thrombosis and new-onset thrombocytopenia.

In the cohort of 116 patients with CVST after COVID-19 vaccination, 78 (67.2%) had thrombosis with TTS and were thus classified as having had a vaccine-related adverse event. These patients were frequently comatose at presentation (24%) and often had intracerebral hemorrhage (68%) and concomitant thromboembolism (36%); 47% died during hospitalization.

These patients were compared with the 38 patients in the same cohort who had CVST but in whom there was no indication of concomitant thrombosis and thrombocytopenia. The case patients were also compared with a control group of 207 patients with CVST who were included in a separate international registry before the COVID-19 pandemic.

Mortality rates were much higher among the patients deemed to have had a vaccine-related CVST. The in-hospital mortality rate was 47%, compared with 5% among the patients in the same cohort who did not have TTS and 3.9% among the prepandemic control group.

The mortality rate was even higher (61%) among patients in the TTS group for whom the diagnosis was made before the condition garnered attention in the scientific community. The mortality rate was 42% among patients diagnosed later.

Of the 78 patients in whom CVST and TTS occurred after COVID-19 vaccination in this cohort, 76 had received the AstraZeneca vaccine (in 75 patients, CVST and TTS occurred after the first vaccination; in one patient, they occurred after the second vaccination). One patient had received the Johnson & Johnson vaccine, and one had received the Pfizer vaccine.

“After more analysis, the case after the Pfizer vaccination is not believed to be caused by the vaccine,” Dr. Coutinho said. “In that case, the patient had a platelet count just below the lower limit and was taking an immunomodulator drug that is known to be associated with thrombocytopenia.”

For two patients who received the AstraZeneca vaccine, there was also an alternative explanation for the thrombocytopenia.

Dr. Coutinho also pointed out that the Johnson & Johnson vaccine has been used mainly in the United States, and these data were largely from other countries.

The median time from vaccination to CVST symptom onset was 9 days in the TTS group. The median platelet count at hospital admission among patients with postvaccination CVST-TTS was 45. Three patients presented with a normal platelet count and developed thrombocytopenia during admission; two patients presented with mild thrombocytopenia, 30 presented with moderate thrombocytopenia, and 43 presented with severe thrombocytopenia.

Antibodies against platelet factor 4 (PF4) were measured in 69 patients with TTS, of whom 63 (91%) tested positive (the one patient in whom TTS occurred after the patient received the Pfizer vaccine did not test positive). However, the researchers note that sensitivity varies among different PF4 ELISA tests. Findings of platelet activation assays were positive in all 36 tested patients.

In the TTS group, 52 patients (67%) received immunomodulation therapy, most often intravenous immunoglobulins (IVIG). Among patients treated with IVIG, the mortality rate was lower (28%).
 

Different from CVST linked to natural COVID-19 infection

Dr. Coutinho noted that CVST can occur in natural SARS-CoV-2 infection but that vaccine-associated CVST is very different.

“In natural COVID-19 infection, there is an increased risk of thrombosis, and some patients can get CVST as a part of this, but in these cases, this is not accompanied by thrombocytopenia. While the CVST in natural COVID-19 infection is also associated with a bad prognosis, this is more to do with the underlying disease. It is normally the very sick COVID patients who develop CVST, and these patients usually die from the underlying disease rather than the CVST itself,” he explained.

“Clinicians need to be aware of vaccine-related CVST, as it requires very specific and rapid treatment,” Dr. Coutinho stressed.

“Patients presenting with an extremely severe headache (unlike any headache they’ve had before) or with seizures or a focal deficit (weakness in arm or problems with speaking or vision) within 4 weeks of an adenovirus COVID-19 vaccination should ring alarm bells. It is important to do diagnostics quickly, with a platelet count the most important first step, and a rapid CT/MRI scan,” he said.

Other tests that should be conducted are D-dimer for thrombosis and the PF4 antibody test. But results for the PF4 antibody test can take days to come back, and clinicians shouldn’t wait for that, Dr. Coutinho notes.

“Specific treatment needs to be given immediately – with anticoagulation (preferably nonheparin) and immunomodulation with IVIG to stop the immune reaction. Platelets should not be given – that may seem counterintuitive in patients with a low platelet count, but giving platelets makes it worse,” he said.
 

Is there a geographic difference?

Dr. Coutinho pointed out that fewer cases of this vaccine-related CVST are being reported at the current time.

“We are not sure why this is the case. These adenovirus vaccines are not being used much now in Western countries, but our collaboration covers many less developed countries in South America and Asia, which are relying heavily on these vaccines. We are now shifting focus to these countries, but so far we have only seen a handful of cases from these areas,” he said.

He suggested that this may be because these countries started their vaccination programs later and are vaccinating their elderly (who are not so susceptible to this side effect) first, or it may be because of some environmental or genetic factor that has not yet been discovered.

“This is now an important research question – is the risk of vaccine-induced CVST the same in different countries or ethnicities? This could influence decisions on future vaccine strategies,” Dr. Coutinho said.

“So far, female sex is the strongest risk factor for vaccine-induced CVST. In our cohort, 81% of cases were in women. In addition, 95% were White, but that doesn’t allow us to conclude that this is a risk factor, as the majority of people who have been vaccinated are White. So, we have no clear insight into that yet,” he said.

In a comment for this news organization, the lead author of the previous U.K. report of a series of 70 cases of cerebral venous thrombosis linked to COVID-19 vaccination, Richard Perry, PhD, University College Hospital, London, described this new report as “an excellent study, with many of the same strengths and weaknesses as our study and has very similar results.”

Dr. Perry noted that the two studies used slightly different definitions of vaccine-induced thrombotic thrombocytopenia, but the cases reported appear to be very similar overall. “It is reassuring and gratifying to see that they have made such similar observations,” he said.

“And as they have drawn their cases from a broad range of countries whereas ours were all from the U.K., this provides evidence that the observations from both studies are reasonably generalizable,” he added.

Dr. Perry pointed out that this new report states that TTS occurred in one patient after the patient had received a second dose of the AstraZeneca vaccine. “I would like to know more about this case, because we didn’t see any cases after a second dose in our cohort,” he said.

Dr. Coutinho responded that he didn’t believe this was the first reported case after the second dose.

The study did not receive any specific funding. Dr. Coutinho has received grants paid to his institution from Boehringer Ingelheim and Bayer and payments paid to his institution for data safety monitoring board participation by Bayer.

A version of this article first appeared on Medscape.com.

A new series of cases of cerebral venous sinus thrombosis (CVST) linked to the adenoviral vector COVID-19 vaccines has been reported, confirming the severity of the reaction and the associated high mortality rate.

The new series comes from an international registry of consecutive patients who experienced CVST within 28 days of COVID-19 vaccination between March 29 and June 18, 2021, from 81 hospitals in 19 countries.

The cases are described in an article published online on Sept. 28. in JAMA Neurology.

“This is a reliable description on the clinical condition of these patients with CVST associated with COVID-19 vaccination. It is striking that this a much worse condition than CVST not associated with COVID-19 vaccination, with a much higher rate of intracerebral hemorrhage and coma and a much higher mortality rate,” senior author Jonathan M. Coutinho, MD, Amsterdam University Medical Centers, told this news organization.

These data confirm the observations from an earlier U.K. cohort in which cases of cerebral venous thrombosis linked to COVID-19 vaccination occurred.

“This is the biggest series, and as an international series, it gives a broader perspective from a larger range of countries,” Dr. Coutinho said. “All the data together show that, although this side effect is rare, the consequences are very severe,” he added.

In the current study, the researchers regarded CVST as being linked to the vaccine if it was accompanied by thrombosis with thrombocytopenia syndrome (TTS), as evidenced by thrombosis and new-onset thrombocytopenia.

In the cohort of 116 patients with CVST after COVID-19 vaccination, 78 (67.2%) had thrombosis with TTS and were thus classified as having had a vaccine-related adverse event. These patients were frequently comatose at presentation (24%) and often had intracerebral hemorrhage (68%) and concomitant thromboembolism (36%); 47% died during hospitalization.

These patients were compared with the 38 patients in the same cohort who had CVST but in whom there was no indication of concomitant thrombosis and thrombocytopenia. The case patients were also compared with a control group of 207 patients with CVST who were included in a separate international registry before the COVID-19 pandemic.

Mortality rates were much higher among the patients deemed to have had a vaccine-related CVST. The in-hospital mortality rate was 47%, compared with 5% among the patients in the same cohort who did not have TTS and 3.9% among the prepandemic control group.

The mortality rate was even higher (61%) among patients in the TTS group for whom the diagnosis was made before the condition garnered attention in the scientific community. The mortality rate was 42% among patients diagnosed later.

Of the 78 patients in whom CVST and TTS occurred after COVID-19 vaccination in this cohort, 76 had received the AstraZeneca vaccine (in 75 patients, CVST and TTS occurred after the first vaccination; in one patient, they occurred after the second vaccination). One patient had received the Johnson & Johnson vaccine, and one had received the Pfizer vaccine.

“After more analysis, the case after the Pfizer vaccination is not believed to be caused by the vaccine,” Dr. Coutinho said. “In that case, the patient had a platelet count just below the lower limit and was taking an immunomodulator drug that is known to be associated with thrombocytopenia.”

For two patients who received the AstraZeneca vaccine, there was also an alternative explanation for the thrombocytopenia.

Dr. Coutinho also pointed out that the Johnson & Johnson vaccine has been used mainly in the United States, and these data were largely from other countries.

The median time from vaccination to CVST symptom onset was 9 days in the TTS group. The median platelet count at hospital admission among patients with postvaccination CVST-TTS was 45. Three patients presented with a normal platelet count and developed thrombocytopenia during admission; two patients presented with mild thrombocytopenia, 30 presented with moderate thrombocytopenia, and 43 presented with severe thrombocytopenia.

Antibodies against platelet factor 4 (PF4) were measured in 69 patients with TTS, of whom 63 (91%) tested positive (the one patient in whom TTS occurred after the patient received the Pfizer vaccine did not test positive). However, the researchers note that sensitivity varies among different PF4 ELISA tests. Findings of platelet activation assays were positive in all 36 tested patients.

In the TTS group, 52 patients (67%) received immunomodulation therapy, most often intravenous immunoglobulins (IVIG). Among patients treated with IVIG, the mortality rate was lower (28%).
 

Different from CVST linked to natural COVID-19 infection

Dr. Coutinho noted that CVST can occur in natural SARS-CoV-2 infection but that vaccine-associated CVST is very different.

“In natural COVID-19 infection, there is an increased risk of thrombosis, and some patients can get CVST as a part of this, but in these cases, this is not accompanied by thrombocytopenia. While the CVST in natural COVID-19 infection is also associated with a bad prognosis, this is more to do with the underlying disease. It is normally the very sick COVID patients who develop CVST, and these patients usually die from the underlying disease rather than the CVST itself,” he explained.

“Clinicians need to be aware of vaccine-related CVST, as it requires very specific and rapid treatment,” Dr. Coutinho stressed.

“Patients presenting with an extremely severe headache (unlike any headache they’ve had before) or with seizures or a focal deficit (weakness in arm or problems with speaking or vision) within 4 weeks of an adenovirus COVID-19 vaccination should ring alarm bells. It is important to do diagnostics quickly, with a platelet count the most important first step, and a rapid CT/MRI scan,” he said.

Other tests that should be conducted are D-dimer for thrombosis and the PF4 antibody test. But results for the PF4 antibody test can take days to come back, and clinicians shouldn’t wait for that, Dr. Coutinho notes.

“Specific treatment needs to be given immediately – with anticoagulation (preferably nonheparin) and immunomodulation with IVIG to stop the immune reaction. Platelets should not be given – that may seem counterintuitive in patients with a low platelet count, but giving platelets makes it worse,” he said.
 

Is there a geographic difference?

Dr. Coutinho pointed out that fewer cases of this vaccine-related CVST are being reported at the current time.

“We are not sure why this is the case. These adenovirus vaccines are not being used much now in Western countries, but our collaboration covers many less developed countries in South America and Asia, which are relying heavily on these vaccines. We are now shifting focus to these countries, but so far we have only seen a handful of cases from these areas,” he said.

He suggested that this may be because these countries started their vaccination programs later and are vaccinating their elderly (who are not so susceptible to this side effect) first, or it may be because of some environmental or genetic factor that has not yet been discovered.

“This is now an important research question – is the risk of vaccine-induced CVST the same in different countries or ethnicities? This could influence decisions on future vaccine strategies,” Dr. Coutinho said.

“So far, female sex is the strongest risk factor for vaccine-induced CVST. In our cohort, 81% of cases were in women. In addition, 95% were White, but that doesn’t allow us to conclude that this is a risk factor, as the majority of people who have been vaccinated are White. So, we have no clear insight into that yet,” he said.

In a comment for this news organization, the lead author of the previous U.K. report of a series of 70 cases of cerebral venous thrombosis linked to COVID-19 vaccination, Richard Perry, PhD, University College Hospital, London, described this new report as “an excellent study, with many of the same strengths and weaknesses as our study and has very similar results.”

Dr. Perry noted that the two studies used slightly different definitions of vaccine-induced thrombotic thrombocytopenia, but the cases reported appear to be very similar overall. “It is reassuring and gratifying to see that they have made such similar observations,” he said.

“And as they have drawn their cases from a broad range of countries whereas ours were all from the U.K., this provides evidence that the observations from both studies are reasonably generalizable,” he added.

Dr. Perry pointed out that this new report states that TTS occurred in one patient after the patient had received a second dose of the AstraZeneca vaccine. “I would like to know more about this case, because we didn’t see any cases after a second dose in our cohort,” he said.

Dr. Coutinho responded that he didn’t believe this was the first reported case after the second dose.

The study did not receive any specific funding. Dr. Coutinho has received grants paid to his institution from Boehringer Ingelheim and Bayer and payments paid to his institution for data safety monitoring board participation by Bayer.

A version of this article first appeared on Medscape.com.

The observed rates of intracranial hemorrhaging (ICH) in patients with hemophilia were higher compared to the general populations among all age groups examined, according to a meta-analysis of studies reported online ahead of print in Blood.

As previously reported, the risk seemed higher in the group of infants and toddlers, and neonates with hemophilia showed a 33-fold higher risk of ICH than newborns in the general population, in the current study.

The researchers performed a literature review and assessed 45 studies that represented 54,470 patients, 809,151 person-years and 5,326 live births of patients with hemophilia. Pooled ICH incidence and mortality were calculated for three age groups: persons of all ages with hemophilia; children and young adults below 25 years of age with hemophilia; and neonates with hemophilia.
 

Overall results

Among the persons of all ages, the pooled ICH incidence and mortality rates were 2.3 (95% confidence interval, 1.2-4.8) and 0.8 (95% CI, 0.5-1.2) per 1,000 person-years, respectively, according to the authors. They found that in children and young adults, the pooled ICH incidence and mortality rates were 7.4 (95% CI, 4.9-11.1) and 0.5 (95% CI, 0.3-0.9) per 1,000 person-years, respectively. In neonates, the pooled cumulative ICH incidence was 2.1% (95% CI, 1.5-2.8) per 100 live births and the pooled ICH cumulative mortality was 0.2% (95% CI, 0.0-1.2) per 100 live births.

Overall, the occurrence of ICH was classified as spontaneous in 35%-58% of cases.
 

Neonates at risk

The observed ICH rates in hemophilia were higher compared to the general populations among the age groups assessed. Neonates showed the highest risk of ICH, which is confirmed by other studies in severe hemophilia demonstrating that neonates were at 11.2 times higher risk for ICH compared with 1- to 12-month-old children, and is also strongly increased compared to neonates in the general populations, the researchers stated.

A previous large study of term infants reported 361 intracranial bleeding episodes per 583,340 live births (0.062% per 100 live births), and comparing this to the current pooled estimate of 2.1% per 100 live births, neonates with hemophilia showed a 33-fold higher risk of ICH than newborns in the general population, according to the researchers.
 

Monitoring and follow-up

“Our findings suggest that adequate follow-up and monitoring of patients is warranted among all ages, especially in the presence of risk factors. Prophylaxis seems to halve ICH risk in children and adults with severe hemophilia, which supports existing recommendations encouraging early initiation of prophylactic treatment,” the authors advised.

Accurate capture of the true frequency of ICH is challenged by considerable clinical heterogeneity, limiting the precision and generalizability of the pooled estimates, leading to the likelihood that ICH and mortality were underdiagnosed in this analysis, according to the authors.

“We found high ICH incidence and mortality rates in patients with hemophilia. Our findings suggest that ICH is still an important problem in hemophilia requiring adequate counseling of patients of all ages,” the researchers concluded.

This work was supported by a grant from Sobi. Some of the authors reported research, consulting or lecturing fees from a variety of pharmaceutical companies, including Sobi.

[email protected]

The observed rates of intracranial hemorrhaging (ICH) in patients with hemophilia were higher compared to the general populations among all age groups examined, according to a meta-analysis of studies reported online ahead of print in Blood.

As previously reported, the risk seemed higher in the group of infants and toddlers, and neonates with hemophilia showed a 33-fold higher risk of ICH than newborns in the general population, in the current study.

The researchers performed a literature review and assessed 45 studies that represented 54,470 patients, 809,151 person-years and 5,326 live births of patients with hemophilia. Pooled ICH incidence and mortality were calculated for three age groups: persons of all ages with hemophilia; children and young adults below 25 years of age with hemophilia; and neonates with hemophilia.
 

Overall results

Among the persons of all ages, the pooled ICH incidence and mortality rates were 2.3 (95% confidence interval, 1.2-4.8) and 0.8 (95% CI, 0.5-1.2) per 1,000 person-years, respectively, according to the authors. They found that in children and young adults, the pooled ICH incidence and mortality rates were 7.4 (95% CI, 4.9-11.1) and 0.5 (95% CI, 0.3-0.9) per 1,000 person-years, respectively. In neonates, the pooled cumulative ICH incidence was 2.1% (95% CI, 1.5-2.8) per 100 live births and the pooled ICH cumulative mortality was 0.2% (95% CI, 0.0-1.2) per 100 live births.

Overall, the occurrence of ICH was classified as spontaneous in 35%-58% of cases.
 

Neonates at risk

The observed ICH rates in hemophilia were higher compared to the general populations among the age groups assessed. Neonates showed the highest risk of ICH, which is confirmed by other studies in severe hemophilia demonstrating that neonates were at 11.2 times higher risk for ICH compared with 1- to 12-month-old children, and is also strongly increased compared to neonates in the general populations, the researchers stated.

A previous large study of term infants reported 361 intracranial bleeding episodes per 583,340 live births (0.062% per 100 live births), and comparing this to the current pooled estimate of 2.1% per 100 live births, neonates with hemophilia showed a 33-fold higher risk of ICH than newborns in the general population, according to the researchers.
 

Monitoring and follow-up

“Our findings suggest that adequate follow-up and monitoring of patients is warranted among all ages, especially in the presence of risk factors. Prophylaxis seems to halve ICH risk in children and adults with severe hemophilia, which supports existing recommendations encouraging early initiation of prophylactic treatment,” the authors advised.

Accurate capture of the true frequency of ICH is challenged by considerable clinical heterogeneity, limiting the precision and generalizability of the pooled estimates, leading to the likelihood that ICH and mortality were underdiagnosed in this analysis, according to the authors.

“We found high ICH incidence and mortality rates in patients with hemophilia. Our findings suggest that ICH is still an important problem in hemophilia requiring adequate counseling of patients of all ages,” the researchers concluded.

This work was supported by a grant from Sobi. Some of the authors reported research, consulting or lecturing fees from a variety of pharmaceutical companies, including Sobi.

[email protected]

The observed rates of intracranial hemorrhaging (ICH) in patients with hemophilia were higher compared to the general populations among all age groups examined, according to a meta-analysis of studies reported online ahead of print in Blood.

As previously reported, the risk seemed higher in the group of infants and toddlers, and neonates with hemophilia showed a 33-fold higher risk of ICH than newborns in the general population, in the current study.

The researchers performed a literature review and assessed 45 studies that represented 54,470 patients, 809,151 person-years and 5,326 live births of patients with hemophilia. Pooled ICH incidence and mortality were calculated for three age groups: persons of all ages with hemophilia; children and young adults below 25 years of age with hemophilia; and neonates with hemophilia.
 

Overall results

Among the persons of all ages, the pooled ICH incidence and mortality rates were 2.3 (95% confidence interval, 1.2-4.8) and 0.8 (95% CI, 0.5-1.2) per 1,000 person-years, respectively, according to the authors. They found that in children and young adults, the pooled ICH incidence and mortality rates were 7.4 (95% CI, 4.9-11.1) and 0.5 (95% CI, 0.3-0.9) per 1,000 person-years, respectively. In neonates, the pooled cumulative ICH incidence was 2.1% (95% CI, 1.5-2.8) per 100 live births and the pooled ICH cumulative mortality was 0.2% (95% CI, 0.0-1.2) per 100 live births.

Overall, the occurrence of ICH was classified as spontaneous in 35%-58% of cases.
 

Neonates at risk

The observed ICH rates in hemophilia were higher compared to the general populations among the age groups assessed. Neonates showed the highest risk of ICH, which is confirmed by other studies in severe hemophilia demonstrating that neonates were at 11.2 times higher risk for ICH compared with 1- to 12-month-old children, and is also strongly increased compared to neonates in the general populations, the researchers stated.

A previous large study of term infants reported 361 intracranial bleeding episodes per 583,340 live births (0.062% per 100 live births), and comparing this to the current pooled estimate of 2.1% per 100 live births, neonates with hemophilia showed a 33-fold higher risk of ICH than newborns in the general population, according to the researchers.
 

Monitoring and follow-up

“Our findings suggest that adequate follow-up and monitoring of patients is warranted among all ages, especially in the presence of risk factors. Prophylaxis seems to halve ICH risk in children and adults with severe hemophilia, which supports existing recommendations encouraging early initiation of prophylactic treatment,” the authors advised.

Accurate capture of the true frequency of ICH is challenged by considerable clinical heterogeneity, limiting the precision and generalizability of the pooled estimates, leading to the likelihood that ICH and mortality were underdiagnosed in this analysis, according to the authors.

“We found high ICH incidence and mortality rates in patients with hemophilia. Our findings suggest that ICH is still an important problem in hemophilia requiring adequate counseling of patients of all ages,” the researchers concluded.

This work was supported by a grant from Sobi. Some of the authors reported research, consulting or lecturing fees from a variety of pharmaceutical companies, including Sobi.

[email protected]

A new study may help doctors assess the long-term risk for major bleeding if anticoagulation for unprovoked venous thromboembolisms (VTE) is continued beyond 3-6 months.

The meta-analysis of data from 27 studies with 17,202 patients was published in the Annals of Internal Medicine. According to two of the paper’s coauthors, Faizan Khan, MSc, and Marc A. Rodger, MD, it “provides best available estimates of long-term bleeding risk with different anticoagulants in patients with unprovoked VTE,” including subgroups at increased risk.

Patients at increased risk for major bleeding include those who are older; those using antiplatelet therapy; and patients with kidney disease, a history of bleeding, or anemia, noted the coauthors, who work for the Ottawa Hospital Research Institute.

The researchers focused on randomized controlled trials (RCTs) and prospective cohort studies that reported major bleeding among patients with a first unprovoked or weakly provoked VTE who received oral anticoagulation for at least 6 months beyond an initial anticoagulant treatment course of at least 3 months.

The investigators analyzed data from 14 RCTs and 13 cohort studies. In all, 9,982 patients received a vitamin K antagonist (VKA), and 7,220 received a direct oral anticoagulant (DOAC).

The incidence of major bleeding per 100 person-years was 1.7 events with VKAs, compared with 1.1 events with DOACs. The researchers estimated that the 5-year cumulative incidence of major bleeding with VKAs was 6.3%. The available data for DOACs were insufficient to estimate the incidence of major bleeding beyond 1 year.

“This information can help clinicians counsel patients and inform shared decision-making about extended therapy,” the researchers said.

Risks of serious bleeding ‘not trivial’

Margaret Fang, MD, with the University of California, San Francisco, agreed that the study can help clinicians and patients weigh the risks of extended anticoagulation for common types of VTE.

The study also “highlights that the risks of serious bleeding are not trivial” and points out gaps in the literature regarding the long-term use of DOACs for extended VTE therapy, Dr. Fang said.

Better ways to predict which patients will develop bleeding on anticoagulants are needed, Dr. Fang added. “It will also be important to establish which of the various therapies for preventing recurrent VTE – full dose versus lowered dose, or even aspirin – has the best balance of safety and efficacy,” she said.

‘Standardized approach’ for identifying high-risk patients lacking

Clinical practice guidelines recommend indefinite anticoagulation for an unprovoked VTE, except when patients are at high risk of bleeding, the authors noted. But clinicians lack a “standardized approach to identify patients at high risk of bleeding,” Mr. Khan and Dr. Rodger said. “Evidence from randomized trials on net long-term benefit of extended therapy is limited, and current guideline recommendations are largely based on expert consensus opinion. Major bleeding events are two to three times more likely to be fatal than recurrent VTE events, so extended therapy is not always associated with a net mortality benefit, particularly in patients at low risk of recurrent VTE or high risk of bleeding.”

The analysis indicates that there is “a clinically meaningful difference in long-term risk for anticoagulant-related major bleeding among patients with a first unprovoked VTE stratified according to presence or absence of the following risk factors: age older than 65 years, creatinine clearance less than 50 mL/min, history of bleeding, concomitant use of antiplatelet therapy, and hemoglobin level less than 100 g/L,” the authors said.

For example, the researchers found that the incidence of major bleeding was higher among those older than 65 years, compared with younger patients (incidence rate ratio, 1.84 with VKAs and 2.92 with DOACs), and among those with creatinine clearance less than 50 mL/min (IRR, 2.83 with VKAs and 3.71 with DOACs).

The case-fatality rate of major bleeding was 8.3% with VKAs and 9.7% with DOACs.

The study received funding from the Canadian Institutes of Health Research. Some of the coauthors are employees of or have financial ties to pharmaceutical companies. Mr. Khan, Dr. Rodger, and Dr. Fang had no relevant disclosures.

[email protected]

A new study may help doctors assess the long-term risk for major bleeding if anticoagulation for unprovoked venous thromboembolisms (VTE) is continued beyond 3-6 months.

The meta-analysis of data from 27 studies with 17,202 patients was published in the Annals of Internal Medicine. According to two of the paper’s coauthors, Faizan Khan, MSc, and Marc A. Rodger, MD, it “provides best available estimates of long-term bleeding risk with different anticoagulants in patients with unprovoked VTE,” including subgroups at increased risk.

Patients at increased risk for major bleeding include those who are older; those using antiplatelet therapy; and patients with kidney disease, a history of bleeding, or anemia, noted the coauthors, who work for the Ottawa Hospital Research Institute.

The researchers focused on randomized controlled trials (RCTs) and prospective cohort studies that reported major bleeding among patients with a first unprovoked or weakly provoked VTE who received oral anticoagulation for at least 6 months beyond an initial anticoagulant treatment course of at least 3 months.

The investigators analyzed data from 14 RCTs and 13 cohort studies. In all, 9,982 patients received a vitamin K antagonist (VKA), and 7,220 received a direct oral anticoagulant (DOAC).

The incidence of major bleeding per 100 person-years was 1.7 events with VKAs, compared with 1.1 events with DOACs. The researchers estimated that the 5-year cumulative incidence of major bleeding with VKAs was 6.3%. The available data for DOACs were insufficient to estimate the incidence of major bleeding beyond 1 year.

“This information can help clinicians counsel patients and inform shared decision-making about extended therapy,” the researchers said.

Risks of serious bleeding ‘not trivial’

Margaret Fang, MD, with the University of California, San Francisco, agreed that the study can help clinicians and patients weigh the risks of extended anticoagulation for common types of VTE.

The study also “highlights that the risks of serious bleeding are not trivial” and points out gaps in the literature regarding the long-term use of DOACs for extended VTE therapy, Dr. Fang said.

Better ways to predict which patients will develop bleeding on anticoagulants are needed, Dr. Fang added. “It will also be important to establish which of the various therapies for preventing recurrent VTE – full dose versus lowered dose, or even aspirin – has the best balance of safety and efficacy,” she said.

‘Standardized approach’ for identifying high-risk patients lacking

Clinical practice guidelines recommend indefinite anticoagulation for an unprovoked VTE, except when patients are at high risk of bleeding, the authors noted. But clinicians lack a “standardized approach to identify patients at high risk of bleeding,” Mr. Khan and Dr. Rodger said. “Evidence from randomized trials on net long-term benefit of extended therapy is limited, and current guideline recommendations are largely based on expert consensus opinion. Major bleeding events are two to three times more likely to be fatal than recurrent VTE events, so extended therapy is not always associated with a net mortality benefit, particularly in patients at low risk of recurrent VTE or high risk of bleeding.”

The analysis indicates that there is “a clinically meaningful difference in long-term risk for anticoagulant-related major bleeding among patients with a first unprovoked VTE stratified according to presence or absence of the following risk factors: age older than 65 years, creatinine clearance less than 50 mL/min, history of bleeding, concomitant use of antiplatelet therapy, and hemoglobin level less than 100 g/L,” the authors said.

For example, the researchers found that the incidence of major bleeding was higher among those older than 65 years, compared with younger patients (incidence rate ratio, 1.84 with VKAs and 2.92 with DOACs), and among those with creatinine clearance less than 50 mL/min (IRR, 2.83 with VKAs and 3.71 with DOACs).

The case-fatality rate of major bleeding was 8.3% with VKAs and 9.7% with DOACs.

The study received funding from the Canadian Institutes of Health Research. Some of the coauthors are employees of or have financial ties to pharmaceutical companies. Mr. Khan, Dr. Rodger, and Dr. Fang had no relevant disclosures.

[email protected]

A new study may help doctors assess the long-term risk for major bleeding if anticoagulation for unprovoked venous thromboembolisms (VTE) is continued beyond 3-6 months.

The meta-analysis of data from 27 studies with 17,202 patients was published in the Annals of Internal Medicine. According to two of the paper’s coauthors, Faizan Khan, MSc, and Marc A. Rodger, MD, it “provides best available estimates of long-term bleeding risk with different anticoagulants in patients with unprovoked VTE,” including subgroups at increased risk.

Patients at increased risk for major bleeding include those who are older; those using antiplatelet therapy; and patients with kidney disease, a history of bleeding, or anemia, noted the coauthors, who work for the Ottawa Hospital Research Institute.

The researchers focused on randomized controlled trials (RCTs) and prospective cohort studies that reported major bleeding among patients with a first unprovoked or weakly provoked VTE who received oral anticoagulation for at least 6 months beyond an initial anticoagulant treatment course of at least 3 months.

The investigators analyzed data from 14 RCTs and 13 cohort studies. In all, 9,982 patients received a vitamin K antagonist (VKA), and 7,220 received a direct oral anticoagulant (DOAC).

The incidence of major bleeding per 100 person-years was 1.7 events with VKAs, compared with 1.1 events with DOACs. The researchers estimated that the 5-year cumulative incidence of major bleeding with VKAs was 6.3%. The available data for DOACs were insufficient to estimate the incidence of major bleeding beyond 1 year.

“This information can help clinicians counsel patients and inform shared decision-making about extended therapy,” the researchers said.

Risks of serious bleeding ‘not trivial’

Margaret Fang, MD, with the University of California, San Francisco, agreed that the study can help clinicians and patients weigh the risks of extended anticoagulation for common types of VTE.

The study also “highlights that the risks of serious bleeding are not trivial” and points out gaps in the literature regarding the long-term use of DOACs for extended VTE therapy, Dr. Fang said.

Better ways to predict which patients will develop bleeding on anticoagulants are needed, Dr. Fang added. “It will also be important to establish which of the various therapies for preventing recurrent VTE – full dose versus lowered dose, or even aspirin – has the best balance of safety and efficacy,” she said.

‘Standardized approach’ for identifying high-risk patients lacking

Clinical practice guidelines recommend indefinite anticoagulation for an unprovoked VTE, except when patients are at high risk of bleeding, the authors noted. But clinicians lack a “standardized approach to identify patients at high risk of bleeding,” Mr. Khan and Dr. Rodger said. “Evidence from randomized trials on net long-term benefit of extended therapy is limited, and current guideline recommendations are largely based on expert consensus opinion. Major bleeding events are two to three times more likely to be fatal than recurrent VTE events, so extended therapy is not always associated with a net mortality benefit, particularly in patients at low risk of recurrent VTE or high risk of bleeding.”

The analysis indicates that there is “a clinically meaningful difference in long-term risk for anticoagulant-related major bleeding among patients with a first unprovoked VTE stratified according to presence or absence of the following risk factors: age older than 65 years, creatinine clearance less than 50 mL/min, history of bleeding, concomitant use of antiplatelet therapy, and hemoglobin level less than 100 g/L,” the authors said.

For example, the researchers found that the incidence of major bleeding was higher among those older than 65 years, compared with younger patients (incidence rate ratio, 1.84 with VKAs and 2.92 with DOACs), and among those with creatinine clearance less than 50 mL/min (IRR, 2.83 with VKAs and 3.71 with DOACs).

The case-fatality rate of major bleeding was 8.3% with VKAs and 9.7% with DOACs.

The study received funding from the Canadian Institutes of Health Research. Some of the coauthors are employees of or have financial ties to pharmaceutical companies. Mr. Khan, Dr. Rodger, and Dr. Fang had no relevant disclosures.

[email protected]

Hemophagocytic lymphohistiocytosis (HLH) is a rare and deadly disease in which unregulated proliferation of histiocytes and T-cell infiltration takes place. It is known as a pediatric disease in which gene defects result in impaired cytotoxic NK- and T-cell function. It has been associated with autosomal recessive inheritance pattern. Without therapy, survival for these patients with active familial HLH is approximately 2 months.

Recognition of the disease has increased over the years, and as a result the diagnosis of HLH in adults also has increased. An acquired form can be triggered by viruses like Epstein-Barr virus, influenza, HIV, lymphoid malignancies, rheumatologic disorders, or immunodeficiency disorders. Survival rates for untreated HLH have been reported at < 5%.¹ Despite early recognition and adequate treatment, HLH carries an overall mortality of 50% in the initial presentation, 90% die in the first 8 weeks of treatment due to uncontrolled disease.²

Case Presentation

A 56-year-old man with no active medical issues except for a remote history of non-Hodgkin lymphoma treated with chemotherapy and splenectomy in 1990 presented to the Veterans Affairs Caribbean Healthcare System in San Juan, Puerto Rico. He was admitted to the medicine ward due to community acquired pneumonia. Three days into admission his clinical status deteriorated, and the patient was transferred to the intensive care unit (ICU) due to acute respiratory failure and sepsis secondary to worsening pneumonia. Chest imaging demonstrated rapidly progressing diffuse bilateral infiltrates. Due to the severity of the chest imaging, a diagnostic bronchoscopy was performed.

The patient’s antibiotics regimen was empirically escalated to vancomycin 1500 mg IV every 12 hours and meropenem 2 g IV every 8 hours. Despite optimization of therapy, the patient did not show clinical signs of improvement. Febrile episodes persisted, pulmonary infiltrates and hypoxemia worsened, and the patient required a neuromuscular blockade. Since the bronchoscopy was nondiagnostic and deterioration persistent, the differential diagnosis was broadened. This led to the ordering of inflammatory markers. Laboratory testing showed ferritin levels > 16,000 ng/mL, pointing to HLH as a possible diagnosis. Further workup was remarkable for triglycerides of 1234 mg/dL and a fibrinogen of 0.77 g/L. In the setting of bicytopenia and persistent fever, HLH-94 regimen was started with dexamethasone 40 mg daily and etoposide 100 mg/m². CD25 levels of 154,701 pg/mL were demonstrated as well as a decreased immunoglobulin (Ig) G levels with absent IgM and IgA. Bone marrow biopsy was consistent with hemophagocytosis. The patient eventually was extubated and sent to the oncology ward to continue chemotherapy.

Discussion

A high clinical suspicion is warranted for rapid diagnosis and treatment as HLH evolves in most cases to multiorgan failure and death. The diagnostic criteria for HLH was developed by the Histiocyte Society in 1991 and then restructured in 2004.^3,4 In the first diagnostic tool developed in 1991, diagnosis was based on 5 criteria (fever, splenomegaly, bicytopenia, hypertriglyceridemia and/or hypofibrinogenemia, and hemophagocytosis). Three additional laboratory findings were also described as part of HLH diagnosis since 2004: low or absent NK-cell-activity, hyperferritinemia of > 500 ng/dL, and high-soluble interleukin-2-receptor levels (CD25) > 2400 U/mL. Overall, 5 of 8 criteria are needed for the HLH diagnosis.

Despite the common use of these diagnostic criteria, they were developed for the pediatric population but have not been validated for adult patients.⁵ For adult patients, the HScore was developed in 2014. It has 9 variables: 3 are based on clinical findings (known underlying immunosuppression, high temperature, and organomegaly; 5 are based on laboratory values (ferritin, serum glutamic oxaloacetic transaminase, cytopenia, triglycerides, and fibrinogen levels); the last variable uses cytologic findings in the bone marrow. In the initial study, probability of having HLH ranged from < 1% with an HScore of ≤ 90% to > 99% with an HScore of ≥ 250 in noncritically ill adults.⁵ A recently published retrospective study demonstrated the diagnostic reliability of both the HLH-2004 criteria and HScore in critically ill adult patients. This study concluded that the best prediction accuracy of HLH diagnosis for a cutoff of 4 fulfilled HLH-2004 criteria had a 95.0% sensitivity and 93.6% specificity and HScore cutoff of 168 reached a 100% sensitivity and 94.1% specificity.⁶

Conclusions

HLH is a rare and deadly disease increasingly more present in adults. Our patient who initially presented with a sepsis diagnosis was suspected of having a hematologic etiology for his clinical findings due to markedly elevated ferritin levels. In our patient, the HLH-94 treatment protocol was used, yielding favorable results. Given the lack of specific scientific data backing updated protocols such as HLH-2004 and a comparatively favorable safety profile, current guidelines still recommend using the HLH-94 treatment protocol. Decreasing ferritin levels may be used in conjunction with clinical improvement to demonstrate therapeutic response. Persistence of disease despite standard treatment may warrant novel therapies, such as emapalumab or HCT. Physicians need to be wary of an HLH diagnosis as early identification and treatment may improve its otherwise grim prognosis.

Hemophagocytic lymphohistiocytosis (HLH) is a rare and deadly disease in which unregulated proliferation of histiocytes and T-cell infiltration takes place. It is known as a pediatric disease in which gene defects result in impaired cytotoxic NK- and T-cell function. It has been associated with autosomal recessive inheritance pattern. Without therapy, survival for these patients with active familial HLH is approximately 2 months.

Recognition of the disease has increased over the years, and as a result the diagnosis of HLH in adults also has increased. An acquired form can be triggered by viruses like Epstein-Barr virus, influenza, HIV, lymphoid malignancies, rheumatologic disorders, or immunodeficiency disorders. Survival rates for untreated HLH have been reported at < 5%.¹ Despite early recognition and adequate treatment, HLH carries an overall mortality of 50% in the initial presentation, 90% die in the first 8 weeks of treatment due to uncontrolled disease.²

Case Presentation

A 56-year-old man with no active medical issues except for a remote history of non-Hodgkin lymphoma treated with chemotherapy and splenectomy in 1990 presented to the Veterans Affairs Caribbean Healthcare System in San Juan, Puerto Rico. He was admitted to the medicine ward due to community acquired pneumonia. Three days into admission his clinical status deteriorated, and the patient was transferred to the intensive care unit (ICU) due to acute respiratory failure and sepsis secondary to worsening pneumonia. Chest imaging demonstrated rapidly progressing diffuse bilateral infiltrates. Due to the severity of the chest imaging, a diagnostic bronchoscopy was performed.

The patient’s antibiotics regimen was empirically escalated to vancomycin 1500 mg IV every 12 hours and meropenem 2 g IV every 8 hours. Despite optimization of therapy, the patient did not show clinical signs of improvement. Febrile episodes persisted, pulmonary infiltrates and hypoxemia worsened, and the patient required a neuromuscular blockade. Since the bronchoscopy was nondiagnostic and deterioration persistent, the differential diagnosis was broadened. This led to the ordering of inflammatory markers. Laboratory testing showed ferritin levels > 16,000 ng/mL, pointing to HLH as a possible diagnosis. Further workup was remarkable for triglycerides of 1234 mg/dL and a fibrinogen of 0.77 g/L. In the setting of bicytopenia and persistent fever, HLH-94 regimen was started with dexamethasone 40 mg daily and etoposide 100 mg/m². CD25 levels of 154,701 pg/mL were demonstrated as well as a decreased immunoglobulin (Ig) G levels with absent IgM and IgA. Bone marrow biopsy was consistent with hemophagocytosis. The patient eventually was extubated and sent to the oncology ward to continue chemotherapy.

Discussion

A high clinical suspicion is warranted for rapid diagnosis and treatment as HLH evolves in most cases to multiorgan failure and death. The diagnostic criteria for HLH was developed by the Histiocyte Society in 1991 and then restructured in 2004.^3,4 In the first diagnostic tool developed in 1991, diagnosis was based on 5 criteria (fever, splenomegaly, bicytopenia, hypertriglyceridemia and/or hypofibrinogenemia, and hemophagocytosis). Three additional laboratory findings were also described as part of HLH diagnosis since 2004: low or absent NK-cell-activity, hyperferritinemia of > 500 ng/dL, and high-soluble interleukin-2-receptor levels (CD25) > 2400 U/mL. Overall, 5 of 8 criteria are needed for the HLH diagnosis.

Despite the common use of these diagnostic criteria, they were developed for the pediatric population but have not been validated for adult patients.⁵ For adult patients, the HScore was developed in 2014. It has 9 variables: 3 are based on clinical findings (known underlying immunosuppression, high temperature, and organomegaly; 5 are based on laboratory values (ferritin, serum glutamic oxaloacetic transaminase, cytopenia, triglycerides, and fibrinogen levels); the last variable uses cytologic findings in the bone marrow. In the initial study, probability of having HLH ranged from < 1% with an HScore of ≤ 90% to > 99% with an HScore of ≥ 250 in noncritically ill adults.⁵ A recently published retrospective study demonstrated the diagnostic reliability of both the HLH-2004 criteria and HScore in critically ill adult patients. This study concluded that the best prediction accuracy of HLH diagnosis for a cutoff of 4 fulfilled HLH-2004 criteria had a 95.0% sensitivity and 93.6% specificity and HScore cutoff of 168 reached a 100% sensitivity and 94.1% specificity.⁶

Conclusions

HLH is a rare and deadly disease increasingly more present in adults. Our patient who initially presented with a sepsis diagnosis was suspected of having a hematologic etiology for his clinical findings due to markedly elevated ferritin levels. In our patient, the HLH-94 treatment protocol was used, yielding favorable results. Given the lack of specific scientific data backing updated protocols such as HLH-2004 and a comparatively favorable safety profile, current guidelines still recommend using the HLH-94 treatment protocol. Decreasing ferritin levels may be used in conjunction with clinical improvement to demonstrate therapeutic response. Persistence of disease despite standard treatment may warrant novel therapies, such as emapalumab or HCT. Physicians need to be wary of an HLH diagnosis as early identification and treatment may improve its otherwise grim prognosis.

Hemophagocytic lymphohistiocytosis (HLH) is a rare and deadly disease in which unregulated proliferation of histiocytes and T-cell infiltration takes place. It is known as a pediatric disease in which gene defects result in impaired cytotoxic NK- and T-cell function. It has been associated with autosomal recessive inheritance pattern. Without therapy, survival for these patients with active familial HLH is approximately 2 months.

Recognition of the disease has increased over the years, and as a result the diagnosis of HLH in adults also has increased. An acquired form can be triggered by viruses like Epstein-Barr virus, influenza, HIV, lymphoid malignancies, rheumatologic disorders, or immunodeficiency disorders. Survival rates for untreated HLH have been reported at < 5%.¹ Despite early recognition and adequate treatment, HLH carries an overall mortality of 50% in the initial presentation, 90% die in the first 8 weeks of treatment due to uncontrolled disease.²

Case Presentation

A 56-year-old man with no active medical issues except for a remote history of non-Hodgkin lymphoma treated with chemotherapy and splenectomy in 1990 presented to the Veterans Affairs Caribbean Healthcare System in San Juan, Puerto Rico. He was admitted to the medicine ward due to community acquired pneumonia. Three days into admission his clinical status deteriorated, and the patient was transferred to the intensive care unit (ICU) due to acute respiratory failure and sepsis secondary to worsening pneumonia. Chest imaging demonstrated rapidly progressing diffuse bilateral infiltrates. Due to the severity of the chest imaging, a diagnostic bronchoscopy was performed.

The patient’s antibiotics regimen was empirically escalated to vancomycin 1500 mg IV every 12 hours and meropenem 2 g IV every 8 hours. Despite optimization of therapy, the patient did not show clinical signs of improvement. Febrile episodes persisted, pulmonary infiltrates and hypoxemia worsened, and the patient required a neuromuscular blockade. Since the bronchoscopy was nondiagnostic and deterioration persistent, the differential diagnosis was broadened. This led to the ordering of inflammatory markers. Laboratory testing showed ferritin levels > 16,000 ng/mL, pointing to HLH as a possible diagnosis. Further workup was remarkable for triglycerides of 1234 mg/dL and a fibrinogen of 0.77 g/L. In the setting of bicytopenia and persistent fever, HLH-94 regimen was started with dexamethasone 40 mg daily and etoposide 100 mg/m². CD25 levels of 154,701 pg/mL were demonstrated as well as a decreased immunoglobulin (Ig) G levels with absent IgM and IgA. Bone marrow biopsy was consistent with hemophagocytosis. The patient eventually was extubated and sent to the oncology ward to continue chemotherapy.

Discussion

A high clinical suspicion is warranted for rapid diagnosis and treatment as HLH evolves in most cases to multiorgan failure and death. The diagnostic criteria for HLH was developed by the Histiocyte Society in 1991 and then restructured in 2004.^3,4 In the first diagnostic tool developed in 1991, diagnosis was based on 5 criteria (fever, splenomegaly, bicytopenia, hypertriglyceridemia and/or hypofibrinogenemia, and hemophagocytosis). Three additional laboratory findings were also described as part of HLH diagnosis since 2004: low or absent NK-cell-activity, hyperferritinemia of > 500 ng/dL, and high-soluble interleukin-2-receptor levels (CD25) > 2400 U/mL. Overall, 5 of 8 criteria are needed for the HLH diagnosis.

Despite the common use of these diagnostic criteria, they were developed for the pediatric population but have not been validated for adult patients.⁵ For adult patients, the HScore was developed in 2014. It has 9 variables: 3 are based on clinical findings (known underlying immunosuppression, high temperature, and organomegaly; 5 are based on laboratory values (ferritin, serum glutamic oxaloacetic transaminase, cytopenia, triglycerides, and fibrinogen levels); the last variable uses cytologic findings in the bone marrow. In the initial study, probability of having HLH ranged from < 1% with an HScore of ≤ 90% to > 99% with an HScore of ≥ 250 in noncritically ill adults.⁵ A recently published retrospective study demonstrated the diagnostic reliability of both the HLH-2004 criteria and HScore in critically ill adult patients. This study concluded that the best prediction accuracy of HLH diagnosis for a cutoff of 4 fulfilled HLH-2004 criteria had a 95.0% sensitivity and 93.6% specificity and HScore cutoff of 168 reached a 100% sensitivity and 94.1% specificity.⁶

Conclusions

HLH is a rare and deadly disease increasingly more present in adults. Our patient who initially presented with a sepsis diagnosis was suspected of having a hematologic etiology for his clinical findings due to markedly elevated ferritin levels. In our patient, the HLH-94 treatment protocol was used, yielding favorable results. Given the lack of specific scientific data backing updated protocols such as HLH-2004 and a comparatively favorable safety profile, current guidelines still recommend using the HLH-94 treatment protocol. Decreasing ferritin levels may be used in conjunction with clinical improvement to demonstrate therapeutic response. Persistence of disease despite standard treatment may warrant novel therapies, such as emapalumab or HCT. Physicians need to be wary of an HLH diagnosis as early identification and treatment may improve its otherwise grim prognosis.

Many pregnant patients are not being screened for iron deficiency despite it being a common cause of anemia in pregnancy that could increase the risk of maternal and infant death.

Researchers analyzed data from 44,552 pregnant patients in Ontario, Canada, collected between 2013 and 2018 to determine the prevalence of ferritin testing, the standard test for iron deficiency, over the course of 5 years.

Their study, published in Blood Advances, revealed that only 59.4% of pregnant persons received a ferritin test, the standard test for iron deficiency. Of those pregnant persons, 25.2% were iron insufficient and 52.8% were iron deficient at least once during pregnancy.

They also found that 71% of these iron tests were ordered during the first trimester, when the risk of iron deficiency is lowest.

“We are not only missing a very large proportion of women who are iron deficient going into pregnancy, but we’re missing those that become iron deficient later on in their pregnancies,” study author Dr. Jennifer Teichman, hematology resident at the University of Toronto, said in an interview. Researchers said iron deficiency during pregnancy is associated with maternal fatigue, cognitive dysfunction, depression, low birth weight, and poor brain development of the child.

Dr. Teichman explained that if iron deficiency during pregnancy is identified early enough, doctors would have enough time to treat the condition with iron supplements before the patient goes into delivery. She also explained prenatal vitamins, which contain some iron, do not contain enough of the mineral to fix iron deficiency.

“One really important point is that the amount of iron contained in a prenatal vitamin is really low,” Dr. Teichman explained. “It’s enough to make up the difference of the additional iron that she needs to sustain her pregnancy, but it’s not enough to treat a woman who’s already got low iron going into pregnancy. So there’s a difference between a prenatal vitamin and true iron supplementation.”

Researchers also found that those who came from a household with a low annual income were even less likely to receive a ferritin test, which was a troubling finding since women of lower socioeconomic status are more likely to be iron deficient in pregnancy. 

“[This] says something about how we as health care providers are contributing to this gap in care,” Dr. Teichman said. “Women of lower socioeconomic status sort of have a triple whammy: They’re more likely to be iron deficient, they’re less likely to have it diagnosed, and they’re less likely to have it corrected.”

Dr. Teichman and her colleagues took a unique approach by looking at isolated ferritin levels as opposed to complete blood counts, which is the typical screening for anemia in pregnancy, said Lissette Tanner, MD, MPH, FACOG, who was not involved with the study.

“Those who meet the criteria for anemia should be evaluated for the cause with initial suspicion for iron deficiency anemia, as that is the most common etiology,” said Dr. Tanner, assistant professor of gynecology and obstetrics at Emory University, Atlanta.

The Centers for Disease Control and Prevention recommends screening for iron deficiency anemia in pregnant persons, in addition to universal iron supplementation to meet the iron requirements of pregnancy.  

Additionally, the American College of Obstetricians and Gynecologists recommends that all pregnant persons be screened for anemia with a complete blood count in the first trimester and again between 24 and 28 weeks of pregnancy.

However, iron deficiency is completely missed by ACOG’s recommendations, said Michael Auerbach, MD, of the department of medicine, Georgetown University, Washington. 

“They recommend a [complete blood count] on all presenting pregnant women, but they do not recommend iron parameters, including a ferritin test, unless the mother is anemic,” said Dr. Auerbach, who was not involved in the study. “I think those guidelines are in need of revision.”

Dr. Teichman hopes her team’s findings will motivate change in obstetric and hematologic guidelines that recommend routine prenatal testing.

“I think ferritin should be a part of routine prenatal testing,” Dr. Teichman said. “And I also think that patients need to be empowered to ask what their iron levels are in pregnancy and providers need to know what a normal iron level is.”

None of the experts interviewed for this story had financial conflicts of interest.

Many pregnant patients are not being screened for iron deficiency despite it being a common cause of anemia in pregnancy that could increase the risk of maternal and infant death.

Researchers analyzed data from 44,552 pregnant patients in Ontario, Canada, collected between 2013 and 2018 to determine the prevalence of ferritin testing, the standard test for iron deficiency, over the course of 5 years.

Their study, published in Blood Advances, revealed that only 59.4% of pregnant persons received a ferritin test, the standard test for iron deficiency. Of those pregnant persons, 25.2% were iron insufficient and 52.8% were iron deficient at least once during pregnancy.

They also found that 71% of these iron tests were ordered during the first trimester, when the risk of iron deficiency is lowest.

“We are not only missing a very large proportion of women who are iron deficient going into pregnancy, but we’re missing those that become iron deficient later on in their pregnancies,” study author Dr. Jennifer Teichman, hematology resident at the University of Toronto, said in an interview. Researchers said iron deficiency during pregnancy is associated with maternal fatigue, cognitive dysfunction, depression, low birth weight, and poor brain development of the child.

Dr. Teichman explained that if iron deficiency during pregnancy is identified early enough, doctors would have enough time to treat the condition with iron supplements before the patient goes into delivery. She also explained prenatal vitamins, which contain some iron, do not contain enough of the mineral to fix iron deficiency.

“One really important point is that the amount of iron contained in a prenatal vitamin is really low,” Dr. Teichman explained. “It’s enough to make up the difference of the additional iron that she needs to sustain her pregnancy, but it’s not enough to treat a woman who’s already got low iron going into pregnancy. So there’s a difference between a prenatal vitamin and true iron supplementation.”

Researchers also found that those who came from a household with a low annual income were even less likely to receive a ferritin test, which was a troubling finding since women of lower socioeconomic status are more likely to be iron deficient in pregnancy. 

“[This] says something about how we as health care providers are contributing to this gap in care,” Dr. Teichman said. “Women of lower socioeconomic status sort of have a triple whammy: They’re more likely to be iron deficient, they’re less likely to have it diagnosed, and they’re less likely to have it corrected.”

Dr. Teichman and her colleagues took a unique approach by looking at isolated ferritin levels as opposed to complete blood counts, which is the typical screening for anemia in pregnancy, said Lissette Tanner, MD, MPH, FACOG, who was not involved with the study.

“Those who meet the criteria for anemia should be evaluated for the cause with initial suspicion for iron deficiency anemia, as that is the most common etiology,” said Dr. Tanner, assistant professor of gynecology and obstetrics at Emory University, Atlanta.

The Centers for Disease Control and Prevention recommends screening for iron deficiency anemia in pregnant persons, in addition to universal iron supplementation to meet the iron requirements of pregnancy.  

Additionally, the American College of Obstetricians and Gynecologists recommends that all pregnant persons be screened for anemia with a complete blood count in the first trimester and again between 24 and 28 weeks of pregnancy.

However, iron deficiency is completely missed by ACOG’s recommendations, said Michael Auerbach, MD, of the department of medicine, Georgetown University, Washington. 

“They recommend a [complete blood count] on all presenting pregnant women, but they do not recommend iron parameters, including a ferritin test, unless the mother is anemic,” said Dr. Auerbach, who was not involved in the study. “I think those guidelines are in need of revision.”

Dr. Teichman hopes her team’s findings will motivate change in obstetric and hematologic guidelines that recommend routine prenatal testing.

“I think ferritin should be a part of routine prenatal testing,” Dr. Teichman said. “And I also think that patients need to be empowered to ask what their iron levels are in pregnancy and providers need to know what a normal iron level is.”

None of the experts interviewed for this story had financial conflicts of interest.

Many pregnant patients are not being screened for iron deficiency despite it being a common cause of anemia in pregnancy that could increase the risk of maternal and infant death.

Researchers analyzed data from 44,552 pregnant patients in Ontario, Canada, collected between 2013 and 2018 to determine the prevalence of ferritin testing, the standard test for iron deficiency, over the course of 5 years.

Their study, published in Blood Advances, revealed that only 59.4% of pregnant persons received a ferritin test, the standard test for iron deficiency. Of those pregnant persons, 25.2% were iron insufficient and 52.8% were iron deficient at least once during pregnancy.

They also found that 71% of these iron tests were ordered during the first trimester, when the risk of iron deficiency is lowest.

“We are not only missing a very large proportion of women who are iron deficient going into pregnancy, but we’re missing those that become iron deficient later on in their pregnancies,” study author Dr. Jennifer Teichman, hematology resident at the University of Toronto, said in an interview. Researchers said iron deficiency during pregnancy is associated with maternal fatigue, cognitive dysfunction, depression, low birth weight, and poor brain development of the child.

Dr. Teichman explained that if iron deficiency during pregnancy is identified early enough, doctors would have enough time to treat the condition with iron supplements before the patient goes into delivery. She also explained prenatal vitamins, which contain some iron, do not contain enough of the mineral to fix iron deficiency.

“One really important point is that the amount of iron contained in a prenatal vitamin is really low,” Dr. Teichman explained. “It’s enough to make up the difference of the additional iron that she needs to sustain her pregnancy, but it’s not enough to treat a woman who’s already got low iron going into pregnancy. So there’s a difference between a prenatal vitamin and true iron supplementation.”

Researchers also found that those who came from a household with a low annual income were even less likely to receive a ferritin test, which was a troubling finding since women of lower socioeconomic status are more likely to be iron deficient in pregnancy. 

“[This] says something about how we as health care providers are contributing to this gap in care,” Dr. Teichman said. “Women of lower socioeconomic status sort of have a triple whammy: They’re more likely to be iron deficient, they’re less likely to have it diagnosed, and they’re less likely to have it corrected.”

Dr. Teichman and her colleagues took a unique approach by looking at isolated ferritin levels as opposed to complete blood counts, which is the typical screening for anemia in pregnancy, said Lissette Tanner, MD, MPH, FACOG, who was not involved with the study.

“Those who meet the criteria for anemia should be evaluated for the cause with initial suspicion for iron deficiency anemia, as that is the most common etiology,” said Dr. Tanner, assistant professor of gynecology and obstetrics at Emory University, Atlanta.

The Centers for Disease Control and Prevention recommends screening for iron deficiency anemia in pregnant persons, in addition to universal iron supplementation to meet the iron requirements of pregnancy.  

Additionally, the American College of Obstetricians and Gynecologists recommends that all pregnant persons be screened for anemia with a complete blood count in the first trimester and again between 24 and 28 weeks of pregnancy.

However, iron deficiency is completely missed by ACOG’s recommendations, said Michael Auerbach, MD, of the department of medicine, Georgetown University, Washington. 

“They recommend a [complete blood count] on all presenting pregnant women, but they do not recommend iron parameters, including a ferritin test, unless the mother is anemic,” said Dr. Auerbach, who was not involved in the study. “I think those guidelines are in need of revision.”

Dr. Teichman hopes her team’s findings will motivate change in obstetric and hematologic guidelines that recommend routine prenatal testing.

“I think ferritin should be a part of routine prenatal testing,” Dr. Teichman said. “And I also think that patients need to be empowered to ask what their iron levels are in pregnancy and providers need to know what a normal iron level is.”

None of the experts interviewed for this story had financial conflicts of interest.

Due to the high cost of newer chemotherapy agents, institutions search for strategies to minimize drug cost and drug waste. Programmed death-1 (PD-1) inhibitors, nivolumab and pembrolizumab, are commonly used in the treatment of solid tumors; however, the agents cost thousands of dollars per dose. Nivolumab and pembrolizumab were initially approved using weight-based dosing, but package labeling for both agents now includes fixed dosing.^1,2 A combination of these 2 dosing strategies could be used by institutions depending on individual patient’s weight to maximize cost savings, minimize drug waste, and maintain safety and efficacy of PD-1 inhibitors. Irrespective of dosing strategy, the development of immune-related adverse events (IrAEs) has been demonstrated with PD-1 inhibitors as a result of the mechanism of action.

PD-1 expression suppresses T cell activity to prevent the development of autoimmunity; however, this is also a mechanism in which tumor cells can evade the host immune system.^3-5 Binding of PD-1 and programmed death-ligand 1 (PD-L1) suppresses T cell activity, whereas the inhibition of PD-1 and PD-L1 results in T cell activation.^4,5 Increased T cell activity elicits the anticancer effect, but also contributes to the development of IrAEs^.4,5 Hypothyroidism is one of the most common IrAEs, with a reported incidence of 9% with nivolumab therapy and 8.5% with pembrolizumab.^1,2

Data from the US Department of Veterans Affairs (VA) medical centers is stored in the centralized Corporate Data Warehouse (CDW). VA researchers can obtain approval to use CDW data, which allows for large scale retrospective review of veterans who have received care at VA medical centers (VAMCs). This study aimed to describe the PD-1 inhibitor dosing used within VAMCs and identify actual and potential cost savings. Due to the frequency of immunemediated hypothyroidism and objective data that can be obtained from CDW reports, the study estimated the incidence of immune-mediated hypothyroidism within the veteran population as a safety outcome.

Background

The US Food and Drug Administration (FDA) initially approved dosing for IV nivolumab at 3 mg/kg of patient body weight every 2 weeks and for IV pembrolizumab 2 mg/kg of patient body weight every 3 weeks.^1,2 Subsequent pharmacokinetic studies found that these agents have similar exposure and efficacy with fixed doses of nivolumab 240 mg IV every 2 weeks and pembrolizumab 200 mg IV every 3 weeks; in 2016, FDA labeling shifted from weight-based dosing to fixed dosing for most solid tumor indications.^6-9 Depending on patient weight, a combination of weightbased and fixed dosing could be used by institutions to maximize cost-savings opportunities, minimize drug waste, and maintain clinical efficacy with PD-1 inhibitors. For example, a patient initiating nivolumab who weighs 80 kg would receive 240 mg for both weight-based (3 mg/kg x 80 kg = 240 mg) and fixed dosing; therefore, no cost-savings opportunities would be available. However, for a patient who weighs ≤ 73.3 kg, it would be more costeffective to use weight-based dosing vs the fixed dose. Since nivolumab is available in 40- mg, 100-mg, and 240-mg vials with similar unit prices, a combination of vial sizes could be used to minimize drug waste. Alternatively, for a patient who weighs ≥ 86.7 kg, it would be more cost-effective to administer the fixed, 240 mg dose when compared with the weightbased dose. Pembrolizumab is available only in a 100-mg vial; therefore, weight-based dosing may result in drug waste.

IrAEs can be seen with PD-1 inhibitors due to increased T cell activity, which is independent of dosing strategy and can affect any organ system. However, immune-mediated hypothyroidism has been commonly seen with PD-1 inhibitors. For patients with immunemediated hypothyroidism, levothyroxine can be considered for asymptomatic patients with thyroid- stimulating hormone (TSH) > 10 uIU/mL with normal thyroxine (T4), or patients with clinical primary hypothyroidism (TSH > 10 uIU/mL with low free T4 and clinical symptoms). Additionally, since hypothyroidism usually follows immunotherapy induced thyrotoxicosis, thyroid function tests should be monitored and levothyroxine initiated if TSH is > 10 uIU/mL for these patients.^10,11

Hypothyroidism also can be graded according to the National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events. Hypothyroidism is considered grade 1 when hypothyroidism is demonstrated through clinical or diagnostic observations only and the patient is asymptomatic and no intervention needed. Grade 2 occurs when the patient is symptomatic and limits instrumental activities of daily living (ADLs), prompting thyroid replacement therapy. In grade 3, patients experience severe symptoms that restrict self-care ADLs, and hospitalization is indicated. Grade 4 has life-threatening consequences, and urgent intervention is indicated. Grade 5 results in the death of the patient.¹²

Electronic health records (EHRs) of veterans who receive care at a VAMC are stored in CDW and available through the VA Informatics and Computing Infrastructure (VINCI), which provides access to data while ensuring veterans’ privacy and data security. This feature of the VA EHR allows for analysis of data across the VA health care system, and larger data sets can be used for retrospective chart reviews.

Using reports from CDW, the primary objective of this study was to describe the dosing strategy used for PD-1 inhibitors, and the primary safety outcome was to determine the incidence of immune-mediated hypothyroidism. The secondary objective was to estimate potential cost-savings opportunities using a combination of PD-1 inhibitor dosing strategies.

Methods

This was a retrospective study including data stored in CDW. The study was approved by the Durham VA Health Care System Institutional Review Board and VINCI/Data Access request tracker. Data were limited to nivolumab and pembrolizumab because they received earlier FDA approval, had multiple solid tumor indications, and 2 FDA-approved dosing strategies. The incidence of IrAEs was limited to hypothyroidism, which could be objectively verified with laboratory monitoring of thyroid function tests, including TSH, free or total T4, and triiodothyronine (T3), all of which were available in CDW data. Additionally, most patients with hypothyroidism initiate treatment with levothyroxine. Prescription refill history could also be retrieved using CDW reports.

Hypothyroidism was defined as T4 below lower limit of normal (LLN), TSH above upper limit of normal (ULN), or any increase in levothyroxine dosage. Patients were excluded if they received PD-1 inhibitor for an indication other than solid tumor treatment, such as hematologic malignancy, or if dosing did not follow weight-based or fixed-dosing strategies, such as nivolumab 1 mg/kg when used in combination with ipilimumab, or pembrolizumab 10 mg/kg. The primary endpoint was the percentage of orders for each dosing strategy, and the primary safety outcome was the incidence of immune-mediated hypothyroidism. Secondary endpoints included estimated cost savings and cost-savings opportunities through nivolumab dose rounding and incidence of levothyroxine initiation or dose change. Descriptive statistics were used for the primary and secondary endpoints.

A report in CDW identified patients who received a dose of nivolumab or pembrolizumab between January 1, 2015 and July 1, 2017 at any VAMC. The CDW report obtained weight at time of PD-1 inhibitor therapy initiation, dose of PD-1 inhibitor given, administration date of PD-1 inhibitor, and VA site. Depending on PD-1 inhibitor administered, weight in kg was multiplied by 3 mg/kg or 2 mg/kg to obtain patient’s anticipated weight-based nivolumab and pembrolizumab dose, respectively. The calculated weight-based dose, fixed dose, and administered dose were compared to infer dosing strategy used at the time of ordering. If the patient’s weight-based dose was within 10% of the fixed dose, the order was categorized as converging because the doses were too similar to determine which dosing strategy was intended.

After determination of dosing strategy, the nivolumab orders were evaluated for actual vs missed cost savings. The cost-savings evaluation included only nivolumab orders because nivolumab is available in a 40-mg, 100-mg, and 240-mg vials and, therefore, has more potential for dose-rounding opportunities with minimal drug waste compared with pembrolizumab, which is available only in a 100-mg vial. Actual cost savings included patients who weighed ≤ 73.3 kg and received nivolumab dose based on 3 mg/kg or patients who weighed ≥ 86.7 kg and received nivolumab 240 mg (fixed dose). Missed cost savings comprised patients who weighed ≤ 73.3 kg who received 240 mg nivolumab or patients who weighed ≥ 86.7 kg and received a nivolumab dose > 240 mg. The cost difference between the dose given and theoretical cost-effective dose was calculated to determine actual and potential cost savings. Converging orders were not included in the cost-savings analysis as the intended nivolumab dose could not be determined. An additional cost analysis of nivolumab orders prescribed between September 1, 2016 and July 1, 2017 was also performed because nivolumab fixed dosing was FDA-approved for most solid tumor indications in September 2016.

To determine the incidence of immunemediated hypothyroidism for patients who received a dose of a PD-1 inhibitor at a VAMC, a CDW report with thyroid function laboratory values (TSH, T4, or T3), including reference range values based on specific VA site, and levothyroxine prescriptions issued during PD-1 inhibitor therapy was obtained. A patient was considered to have experienced immune-mediated hypothyroidism if the patient’s laboratory values demonstrated T4 below the LLN, TSH above the ULN, or if the medication fill history demonstrated levothyroxine initiation or a levothyroxine dose increase.

Results 

The CDW report identified 32,769 total PD-1 inhibitor orders. There were 3982 orders that did not meet inclusion criteria or inadequate data were obtained with CDW report and were excluded (Figure). The remaining 28,787 PD-1 inhibitor orders were evaluated for actual or missed cost savings. The distribution of dosing strategies can be found in Table 1.

Nivolumab accounted for 81.5% of all PD-1 inhibitor orders. Using the most cost-effective nivolumab dosing, the actual cost savings was estimated to be $8,514,300 with potential additional $5,591,250 of missed cost-savings opportunities. There were 8013 nivolumab orders written between September 1, 2016 and July 1, 2017. Cost-effective dosing was used in 4687 of these orders, which accounted for a cost savings of $5,198,570. The remaining 3326 orders had a missed cost-savings opportunity, which accounted for an additional $2,907,180 potential cost savings (Table 2).

PD-1 inhibitors were used for the treatment of 3249 unique patients. Based on abnormal thyroid function tests and levothyroxine initiation or dose increase, it is estimated that 514 (15.8%) patients experienced hypothyroidism during PD-1 inhibitor therapy. However, prior to PD-1 inhibitor therapy, 274 patients were receiving levothyroxine, suggesting baseline thyroid dysfunction. Of these patients, 152 (55.5%) patients maintained the same levothyroxine dose during PD-1 inhibitor therapy, but 91 (33.2%) required a levothyroxine dose increase. There were 187 patients who initiated levothyroxine during PD-1 inhibitor therapy (Table 3).

Discussion

Changes in FDA-approved dosing for PD-1 inhibitors allowed a combination of dosing strategies. Depending on patient weight, a weight-based or fixed-dosing strategy can be used to reduce drug cost while maintaining equivalent efficacy. This study evaluated use of dose rounding for PD-1 inhibitors within the VA health care system to identify actual and potential cost savings. To our knowledge, this is the first study to demonstrate cost savings through use of a combination of PD-1 inhibitor dosing strategies. Using CDW, researchers were able to review PD-1 dosing from all VAMCs and include a larger number of orders in a single retrospective study.

Nivolumab was the primary agent used within VAMCs. Depending on the indication, pembrolizumab requires PD-1 expression testing prior to its use in several solid tumor indications. Consequently, additional testing and patient eligibility is needed prior to use. Both PD-1 inhibitors were primarily dosed based on patient weight since this was the first FDAapproved dosing strategy. Nivolumab had more orders categorized as converging, which may be due to the therapeutic weight-based dose of 3 mg/kg for nivolumab vs 2 mg/kg for pembrolizumab. The calculated weight-based dose of nivolumab for an 80-kg patient is 240 mg, which also is the fixed dose. A 80-kg patient on pembrolizumab at 2 mg/kg would receive a 160-mg dose, whereas the fixed dose of pembrolizumab is 200 mg. Pembrolizumab is available only in a 100-mg vial, which limits opportunities for dose rounding without drug waste and could explain the higher amount of pembrolizumab orders in the fixed-dose category.

In this review of PD-1 inhibitor orders over approximately a 2.5-year study period, we identified $8,514,300 estimated cost savings with $5,591,250 estimated missed cost savings. When looking at orders administered after FDA approval for nivolumab-fixed dosing in September 2016, there was substantial cost savings of $5,198,570 with the potential for an additional $2,907,180 missed cost savings. Due to lower drug acquisition costs within the VA health care system, there may be higher cost-savings opportunities within other health care systems.

Through review of abnormal thyroid laboratory values and levothyroxine initiation or dose changes, this study estimated the incidence of hypothyroidism in patients receiving PD-1 inhibitor therapy at the VA. The incidence of primary hypothyroidism identified in this study was slightly higher at 15.8% compared with the 8.5 to 9.0% incidence reported from clinical trials.^1,2 There are several reasons why the incidence of hypothyroidism appeared higher in this study. Abnormal laboratory values were not assessed for the degree of deviation from the reference range; any TSH above the ULN, T4 below the LLN, or levothyroxine dose increase was included as thyroid dysfunction in this review. There is also the potential for endogenous age-related thyroid fluctuation, and the development of hypothyroidism may not have been related to PD-1 inhibitor therapy. Within this patient population, 8.4% were receiving levothyroxine prior to PD-1 inhibitor initiation indicating baseline thyroid dysfunction, and it is unclear whether levothyroxine dose increases were due to PD-1 inhibitor or endogenous fluctuation.

Limitations

There are several limitations to acknowledge. The dosing strategy and apparent dose rounding was determined by investigator inference and may not accurately represent the intended dosing strategy. This study did not address efficacy of PD-1 inhibitor and dosing strategy; however, clinical trials have demonstrated equivalent efficacy to generate the change in FDA-approved dosing. Additionally, FDA approval for nivolumab fixed dosing was indication specific. Starting in September 2016, many solid tumor indications had fixed dosing approved, but this approval was not necessarily all encompassing.

While the use of CDW allowed for a greater number of PD-1 inhibitor orders to be included in retrospective review, there also were limitations of the CDW report. The patient weight was limited to weight at time of therapy initiation. Due to the potential for weight changes, nivolumab dosing may have seemed inappropriate to investigators, and thereby excluded. Based on data available from CDW reports, hypothyroidism could not be graded according to NCI Common Terminology Criteria for Adverse Events, and the incidence of clinically significant hypothyroidism could not be determined.

Conclusions

With increasing drug acquisition costs, particularly among antineoplastic agents, health care systems frequently seek out cost-savings opportunities. Using a combination of weightbased and fixed-dosing strategies for PD-1 inhibitors can be a mechanism to achieve costsavings. Through the identification of the dosing strategy used for PD-1 inhibitors, we were able to identify and report instances for potential cost-savings opportunities among veterans treated within VA health care system. Use of CDW allows for data from all VAMCs to be evaluated in a single retrospective chart review, which allows for the inclusion of a larger sample size. This study identified a substantial cost savings for nivolumab through a combination of weight-based and fixed-dosing strategies. Due to the novel mechanism of action, ongoing realworld evaluation of adverse events and IrAEs is warranted.

Dosing strategies with nivolumab and pembrolizumab continue to evolve. In March 2018, nivolumab 480 mg IV every 4 weeks was FDA approved and in April 2020, pembrolizumab 400 mg IV every 6 weeks was FDA approved.^13,14 While the drug costs will remain the same, extended interval dosing strategies have cost avoidance such as fewer clinic appointments, resulting in decreased staffing costs and decreased patient travel. Additional studies will be needed to evaluate the cost and safety of the recently approved dosing strategies

Due to the high cost of newer chemotherapy agents, institutions search for strategies to minimize drug cost and drug waste. Programmed death-1 (PD-1) inhibitors, nivolumab and pembrolizumab, are commonly used in the treatment of solid tumors; however, the agents cost thousands of dollars per dose. Nivolumab and pembrolizumab were initially approved using weight-based dosing, but package labeling for both agents now includes fixed dosing.^1,2 A combination of these 2 dosing strategies could be used by institutions depending on individual patient’s weight to maximize cost savings, minimize drug waste, and maintain safety and efficacy of PD-1 inhibitors. Irrespective of dosing strategy, the development of immune-related adverse events (IrAEs) has been demonstrated with PD-1 inhibitors as a result of the mechanism of action.

PD-1 expression suppresses T cell activity to prevent the development of autoimmunity; however, this is also a mechanism in which tumor cells can evade the host immune system.^3-5 Binding of PD-1 and programmed death-ligand 1 (PD-L1) suppresses T cell activity, whereas the inhibition of PD-1 and PD-L1 results in T cell activation.^4,5 Increased T cell activity elicits the anticancer effect, but also contributes to the development of IrAEs^.4,5 Hypothyroidism is one of the most common IrAEs, with a reported incidence of 9% with nivolumab therapy and 8.5% with pembrolizumab.^1,2

Data from the US Department of Veterans Affairs (VA) medical centers is stored in the centralized Corporate Data Warehouse (CDW). VA researchers can obtain approval to use CDW data, which allows for large scale retrospective review of veterans who have received care at VA medical centers (VAMCs). This study aimed to describe the PD-1 inhibitor dosing used within VAMCs and identify actual and potential cost savings. Due to the frequency of immunemediated hypothyroidism and objective data that can be obtained from CDW reports, the study estimated the incidence of immune-mediated hypothyroidism within the veteran population as a safety outcome.

Background

The US Food and Drug Administration (FDA) initially approved dosing for IV nivolumab at 3 mg/kg of patient body weight every 2 weeks and for IV pembrolizumab 2 mg/kg of patient body weight every 3 weeks.^1,2 Subsequent pharmacokinetic studies found that these agents have similar exposure and efficacy with fixed doses of nivolumab 240 mg IV every 2 weeks and pembrolizumab 200 mg IV every 3 weeks; in 2016, FDA labeling shifted from weight-based dosing to fixed dosing for most solid tumor indications.^6-9 Depending on patient weight, a combination of weightbased and fixed dosing could be used by institutions to maximize cost-savings opportunities, minimize drug waste, and maintain clinical efficacy with PD-1 inhibitors. For example, a patient initiating nivolumab who weighs 80 kg would receive 240 mg for both weight-based (3 mg/kg x 80 kg = 240 mg) and fixed dosing; therefore, no cost-savings opportunities would be available. However, for a patient who weighs ≤ 73.3 kg, it would be more costeffective to use weight-based dosing vs the fixed dose. Since nivolumab is available in 40- mg, 100-mg, and 240-mg vials with similar unit prices, a combination of vial sizes could be used to minimize drug waste. Alternatively, for a patient who weighs ≥ 86.7 kg, it would be more cost-effective to administer the fixed, 240 mg dose when compared with the weightbased dose. Pembrolizumab is available only in a 100-mg vial; therefore, weight-based dosing may result in drug waste.

IrAEs can be seen with PD-1 inhibitors due to increased T cell activity, which is independent of dosing strategy and can affect any organ system. However, immune-mediated hypothyroidism has been commonly seen with PD-1 inhibitors. For patients with immunemediated hypothyroidism, levothyroxine can be considered for asymptomatic patients with thyroid- stimulating hormone (TSH) > 10 uIU/mL with normal thyroxine (T4), or patients with clinical primary hypothyroidism (TSH > 10 uIU/mL with low free T4 and clinical symptoms). Additionally, since hypothyroidism usually follows immunotherapy induced thyrotoxicosis, thyroid function tests should be monitored and levothyroxine initiated if TSH is > 10 uIU/mL for these patients.^10,11

Hypothyroidism also can be graded according to the National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events. Hypothyroidism is considered grade 1 when hypothyroidism is demonstrated through clinical or diagnostic observations only and the patient is asymptomatic and no intervention needed. Grade 2 occurs when the patient is symptomatic and limits instrumental activities of daily living (ADLs), prompting thyroid replacement therapy. In grade 3, patients experience severe symptoms that restrict self-care ADLs, and hospitalization is indicated. Grade 4 has life-threatening consequences, and urgent intervention is indicated. Grade 5 results in the death of the patient.¹²

Electronic health records (EHRs) of veterans who receive care at a VAMC are stored in CDW and available through the VA Informatics and Computing Infrastructure (VINCI), which provides access to data while ensuring veterans’ privacy and data security. This feature of the VA EHR allows for analysis of data across the VA health care system, and larger data sets can be used for retrospective chart reviews.

Using reports from CDW, the primary objective of this study was to describe the dosing strategy used for PD-1 inhibitors, and the primary safety outcome was to determine the incidence of immune-mediated hypothyroidism. The secondary objective was to estimate potential cost-savings opportunities using a combination of PD-1 inhibitor dosing strategies.

Methods

This was a retrospective study including data stored in CDW. The study was approved by the Durham VA Health Care System Institutional Review Board and VINCI/Data Access request tracker. Data were limited to nivolumab and pembrolizumab because they received earlier FDA approval, had multiple solid tumor indications, and 2 FDA-approved dosing strategies. The incidence of IrAEs was limited to hypothyroidism, which could be objectively verified with laboratory monitoring of thyroid function tests, including TSH, free or total T4, and triiodothyronine (T3), all of which were available in CDW data. Additionally, most patients with hypothyroidism initiate treatment with levothyroxine. Prescription refill history could also be retrieved using CDW reports.

Hypothyroidism was defined as T4 below lower limit of normal (LLN), TSH above upper limit of normal (ULN), or any increase in levothyroxine dosage. Patients were excluded if they received PD-1 inhibitor for an indication other than solid tumor treatment, such as hematologic malignancy, or if dosing did not follow weight-based or fixed-dosing strategies, such as nivolumab 1 mg/kg when used in combination with ipilimumab, or pembrolizumab 10 mg/kg. The primary endpoint was the percentage of orders for each dosing strategy, and the primary safety outcome was the incidence of immune-mediated hypothyroidism. Secondary endpoints included estimated cost savings and cost-savings opportunities through nivolumab dose rounding and incidence of levothyroxine initiation or dose change. Descriptive statistics were used for the primary and secondary endpoints.

A report in CDW identified patients who received a dose of nivolumab or pembrolizumab between January 1, 2015 and July 1, 2017 at any VAMC. The CDW report obtained weight at time of PD-1 inhibitor therapy initiation, dose of PD-1 inhibitor given, administration date of PD-1 inhibitor, and VA site. Depending on PD-1 inhibitor administered, weight in kg was multiplied by 3 mg/kg or 2 mg/kg to obtain patient’s anticipated weight-based nivolumab and pembrolizumab dose, respectively. The calculated weight-based dose, fixed dose, and administered dose were compared to infer dosing strategy used at the time of ordering. If the patient’s weight-based dose was within 10% of the fixed dose, the order was categorized as converging because the doses were too similar to determine which dosing strategy was intended.

After determination of dosing strategy, the nivolumab orders were evaluated for actual vs missed cost savings. The cost-savings evaluation included only nivolumab orders because nivolumab is available in a 40-mg, 100-mg, and 240-mg vials and, therefore, has more potential for dose-rounding opportunities with minimal drug waste compared with pembrolizumab, which is available only in a 100-mg vial. Actual cost savings included patients who weighed ≤ 73.3 kg and received nivolumab dose based on 3 mg/kg or patients who weighed ≥ 86.7 kg and received nivolumab 240 mg (fixed dose). Missed cost savings comprised patients who weighed ≤ 73.3 kg who received 240 mg nivolumab or patients who weighed ≥ 86.7 kg and received a nivolumab dose > 240 mg. The cost difference between the dose given and theoretical cost-effective dose was calculated to determine actual and potential cost savings. Converging orders were not included in the cost-savings analysis as the intended nivolumab dose could not be determined. An additional cost analysis of nivolumab orders prescribed between September 1, 2016 and July 1, 2017 was also performed because nivolumab fixed dosing was FDA-approved for most solid tumor indications in September 2016.

To determine the incidence of immunemediated hypothyroidism for patients who received a dose of a PD-1 inhibitor at a VAMC, a CDW report with thyroid function laboratory values (TSH, T4, or T3), including reference range values based on specific VA site, and levothyroxine prescriptions issued during PD-1 inhibitor therapy was obtained. A patient was considered to have experienced immune-mediated hypothyroidism if the patient’s laboratory values demonstrated T4 below the LLN, TSH above the ULN, or if the medication fill history demonstrated levothyroxine initiation or a levothyroxine dose increase.

Results 

The CDW report identified 32,769 total PD-1 inhibitor orders. There were 3982 orders that did not meet inclusion criteria or inadequate data were obtained with CDW report and were excluded (Figure). The remaining 28,787 PD-1 inhibitor orders were evaluated for actual or missed cost savings. The distribution of dosing strategies can be found in Table 1.

Nivolumab accounted for 81.5% of all PD-1 inhibitor orders. Using the most cost-effective nivolumab dosing, the actual cost savings was estimated to be $8,514,300 with potential additional $5,591,250 of missed cost-savings opportunities. There were 8013 nivolumab orders written between September 1, 2016 and July 1, 2017. Cost-effective dosing was used in 4687 of these orders, which accounted for a cost savings of $5,198,570. The remaining 3326 orders had a missed cost-savings opportunity, which accounted for an additional $2,907,180 potential cost savings (Table 2).

PD-1 inhibitors were used for the treatment of 3249 unique patients. Based on abnormal thyroid function tests and levothyroxine initiation or dose increase, it is estimated that 514 (15.8%) patients experienced hypothyroidism during PD-1 inhibitor therapy. However, prior to PD-1 inhibitor therapy, 274 patients were receiving levothyroxine, suggesting baseline thyroid dysfunction. Of these patients, 152 (55.5%) patients maintained the same levothyroxine dose during PD-1 inhibitor therapy, but 91 (33.2%) required a levothyroxine dose increase. There were 187 patients who initiated levothyroxine during PD-1 inhibitor therapy (Table 3).

Discussion

Changes in FDA-approved dosing for PD-1 inhibitors allowed a combination of dosing strategies. Depending on patient weight, a weight-based or fixed-dosing strategy can be used to reduce drug cost while maintaining equivalent efficacy. This study evaluated use of dose rounding for PD-1 inhibitors within the VA health care system to identify actual and potential cost savings. To our knowledge, this is the first study to demonstrate cost savings through use of a combination of PD-1 inhibitor dosing strategies. Using CDW, researchers were able to review PD-1 dosing from all VAMCs and include a larger number of orders in a single retrospective study.

Nivolumab was the primary agent used within VAMCs. Depending on the indication, pembrolizumab requires PD-1 expression testing prior to its use in several solid tumor indications. Consequently, additional testing and patient eligibility is needed prior to use. Both PD-1 inhibitors were primarily dosed based on patient weight since this was the first FDAapproved dosing strategy. Nivolumab had more orders categorized as converging, which may be due to the therapeutic weight-based dose of 3 mg/kg for nivolumab vs 2 mg/kg for pembrolizumab. The calculated weight-based dose of nivolumab for an 80-kg patient is 240 mg, which also is the fixed dose. A 80-kg patient on pembrolizumab at 2 mg/kg would receive a 160-mg dose, whereas the fixed dose of pembrolizumab is 200 mg. Pembrolizumab is available only in a 100-mg vial, which limits opportunities for dose rounding without drug waste and could explain the higher amount of pembrolizumab orders in the fixed-dose category.

In this review of PD-1 inhibitor orders over approximately a 2.5-year study period, we identified $8,514,300 estimated cost savings with $5,591,250 estimated missed cost savings. When looking at orders administered after FDA approval for nivolumab-fixed dosing in September 2016, there was substantial cost savings of $5,198,570 with the potential for an additional $2,907,180 missed cost savings. Due to lower drug acquisition costs within the VA health care system, there may be higher cost-savings opportunities within other health care systems.

Through review of abnormal thyroid laboratory values and levothyroxine initiation or dose changes, this study estimated the incidence of hypothyroidism in patients receiving PD-1 inhibitor therapy at the VA. The incidence of primary hypothyroidism identified in this study was slightly higher at 15.8% compared with the 8.5 to 9.0% incidence reported from clinical trials.^1,2 There are several reasons why the incidence of hypothyroidism appeared higher in this study. Abnormal laboratory values were not assessed for the degree of deviation from the reference range; any TSH above the ULN, T4 below the LLN, or levothyroxine dose increase was included as thyroid dysfunction in this review. There is also the potential for endogenous age-related thyroid fluctuation, and the development of hypothyroidism may not have been related to PD-1 inhibitor therapy. Within this patient population, 8.4% were receiving levothyroxine prior to PD-1 inhibitor initiation indicating baseline thyroid dysfunction, and it is unclear whether levothyroxine dose increases were due to PD-1 inhibitor or endogenous fluctuation.

Limitations

There are several limitations to acknowledge. The dosing strategy and apparent dose rounding was determined by investigator inference and may not accurately represent the intended dosing strategy. This study did not address efficacy of PD-1 inhibitor and dosing strategy; however, clinical trials have demonstrated equivalent efficacy to generate the change in FDA-approved dosing. Additionally, FDA approval for nivolumab fixed dosing was indication specific. Starting in September 2016, many solid tumor indications had fixed dosing approved, but this approval was not necessarily all encompassing.

While the use of CDW allowed for a greater number of PD-1 inhibitor orders to be included in retrospective review, there also were limitations of the CDW report. The patient weight was limited to weight at time of therapy initiation. Due to the potential for weight changes, nivolumab dosing may have seemed inappropriate to investigators, and thereby excluded. Based on data available from CDW reports, hypothyroidism could not be graded according to NCI Common Terminology Criteria for Adverse Events, and the incidence of clinically significant hypothyroidism could not be determined.

Conclusions

With increasing drug acquisition costs, particularly among antineoplastic agents, health care systems frequently seek out cost-savings opportunities. Using a combination of weightbased and fixed-dosing strategies for PD-1 inhibitors can be a mechanism to achieve costsavings. Through the identification of the dosing strategy used for PD-1 inhibitors, we were able to identify and report instances for potential cost-savings opportunities among veterans treated within VA health care system. Use of CDW allows for data from all VAMCs to be evaluated in a single retrospective chart review, which allows for the inclusion of a larger sample size. This study identified a substantial cost savings for nivolumab through a combination of weight-based and fixed-dosing strategies. Due to the novel mechanism of action, ongoing realworld evaluation of adverse events and IrAEs is warranted.

Dosing strategies with nivolumab and pembrolizumab continue to evolve. In March 2018, nivolumab 480 mg IV every 4 weeks was FDA approved and in April 2020, pembrolizumab 400 mg IV every 6 weeks was FDA approved.^13,14 While the drug costs will remain the same, extended interval dosing strategies have cost avoidance such as fewer clinic appointments, resulting in decreased staffing costs and decreased patient travel. Additional studies will be needed to evaluate the cost and safety of the recently approved dosing strategies

Due to the high cost of newer chemotherapy agents, institutions search for strategies to minimize drug cost and drug waste. Programmed death-1 (PD-1) inhibitors, nivolumab and pembrolizumab, are commonly used in the treatment of solid tumors; however, the agents cost thousands of dollars per dose. Nivolumab and pembrolizumab were initially approved using weight-based dosing, but package labeling for both agents now includes fixed dosing.^1,2 A combination of these 2 dosing strategies could be used by institutions depending on individual patient’s weight to maximize cost savings, minimize drug waste, and maintain safety and efficacy of PD-1 inhibitors. Irrespective of dosing strategy, the development of immune-related adverse events (IrAEs) has been demonstrated with PD-1 inhibitors as a result of the mechanism of action.

PD-1 expression suppresses T cell activity to prevent the development of autoimmunity; however, this is also a mechanism in which tumor cells can evade the host immune system.^3-5 Binding of PD-1 and programmed death-ligand 1 (PD-L1) suppresses T cell activity, whereas the inhibition of PD-1 and PD-L1 results in T cell activation.^4,5 Increased T cell activity elicits the anticancer effect, but also contributes to the development of IrAEs^.4,5 Hypothyroidism is one of the most common IrAEs, with a reported incidence of 9% with nivolumab therapy and 8.5% with pembrolizumab.^1,2

Data from the US Department of Veterans Affairs (VA) medical centers is stored in the centralized Corporate Data Warehouse (CDW). VA researchers can obtain approval to use CDW data, which allows for large scale retrospective review of veterans who have received care at VA medical centers (VAMCs). This study aimed to describe the PD-1 inhibitor dosing used within VAMCs and identify actual and potential cost savings. Due to the frequency of immunemediated hypothyroidism and objective data that can be obtained from CDW reports, the study estimated the incidence of immune-mediated hypothyroidism within the veteran population as a safety outcome.

Background

The US Food and Drug Administration (FDA) initially approved dosing for IV nivolumab at 3 mg/kg of patient body weight every 2 weeks and for IV pembrolizumab 2 mg/kg of patient body weight every 3 weeks.^1,2 Subsequent pharmacokinetic studies found that these agents have similar exposure and efficacy with fixed doses of nivolumab 240 mg IV every 2 weeks and pembrolizumab 200 mg IV every 3 weeks; in 2016, FDA labeling shifted from weight-based dosing to fixed dosing for most solid tumor indications.^6-9 Depending on patient weight, a combination of weightbased and fixed dosing could be used by institutions to maximize cost-savings opportunities, minimize drug waste, and maintain clinical efficacy with PD-1 inhibitors. For example, a patient initiating nivolumab who weighs 80 kg would receive 240 mg for both weight-based (3 mg/kg x 80 kg = 240 mg) and fixed dosing; therefore, no cost-savings opportunities would be available. However, for a patient who weighs ≤ 73.3 kg, it would be more costeffective to use weight-based dosing vs the fixed dose. Since nivolumab is available in 40- mg, 100-mg, and 240-mg vials with similar unit prices, a combination of vial sizes could be used to minimize drug waste. Alternatively, for a patient who weighs ≥ 86.7 kg, it would be more cost-effective to administer the fixed, 240 mg dose when compared with the weightbased dose. Pembrolizumab is available only in a 100-mg vial; therefore, weight-based dosing may result in drug waste.

IrAEs can be seen with PD-1 inhibitors due to increased T cell activity, which is independent of dosing strategy and can affect any organ system. However, immune-mediated hypothyroidism has been commonly seen with PD-1 inhibitors. For patients with immunemediated hypothyroidism, levothyroxine can be considered for asymptomatic patients with thyroid- stimulating hormone (TSH) > 10 uIU/mL with normal thyroxine (T4), or patients with clinical primary hypothyroidism (TSH > 10 uIU/mL with low free T4 and clinical symptoms). Additionally, since hypothyroidism usually follows immunotherapy induced thyrotoxicosis, thyroid function tests should be monitored and levothyroxine initiated if TSH is > 10 uIU/mL for these patients.^10,11

Hypothyroidism also can be graded according to the National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events. Hypothyroidism is considered grade 1 when hypothyroidism is demonstrated through clinical or diagnostic observations only and the patient is asymptomatic and no intervention needed. Grade 2 occurs when the patient is symptomatic and limits instrumental activities of daily living (ADLs), prompting thyroid replacement therapy. In grade 3, patients experience severe symptoms that restrict self-care ADLs, and hospitalization is indicated. Grade 4 has life-threatening consequences, and urgent intervention is indicated. Grade 5 results in the death of the patient.¹²

Electronic health records (EHRs) of veterans who receive care at a VAMC are stored in CDW and available through the VA Informatics and Computing Infrastructure (VINCI), which provides access to data while ensuring veterans’ privacy and data security. This feature of the VA EHR allows for analysis of data across the VA health care system, and larger data sets can be used for retrospective chart reviews.

Using reports from CDW, the primary objective of this study was to describe the dosing strategy used for PD-1 inhibitors, and the primary safety outcome was to determine the incidence of immune-mediated hypothyroidism. The secondary objective was to estimate potential cost-savings opportunities using a combination of PD-1 inhibitor dosing strategies.

Methods

This was a retrospective study including data stored in CDW. The study was approved by the Durham VA Health Care System Institutional Review Board and VINCI/Data Access request tracker. Data were limited to nivolumab and pembrolizumab because they received earlier FDA approval, had multiple solid tumor indications, and 2 FDA-approved dosing strategies. The incidence of IrAEs was limited to hypothyroidism, which could be objectively verified with laboratory monitoring of thyroid function tests, including TSH, free or total T4, and triiodothyronine (T3), all of which were available in CDW data. Additionally, most patients with hypothyroidism initiate treatment with levothyroxine. Prescription refill history could also be retrieved using CDW reports.

Hypothyroidism was defined as T4 below lower limit of normal (LLN), TSH above upper limit of normal (ULN), or any increase in levothyroxine dosage. Patients were excluded if they received PD-1 inhibitor for an indication other than solid tumor treatment, such as hematologic malignancy, or if dosing did not follow weight-based or fixed-dosing strategies, such as nivolumab 1 mg/kg when used in combination with ipilimumab, or pembrolizumab 10 mg/kg. The primary endpoint was the percentage of orders for each dosing strategy, and the primary safety outcome was the incidence of immune-mediated hypothyroidism. Secondary endpoints included estimated cost savings and cost-savings opportunities through nivolumab dose rounding and incidence of levothyroxine initiation or dose change. Descriptive statistics were used for the primary and secondary endpoints.

A report in CDW identified patients who received a dose of nivolumab or pembrolizumab between January 1, 2015 and July 1, 2017 at any VAMC. The CDW report obtained weight at time of PD-1 inhibitor therapy initiation, dose of PD-1 inhibitor given, administration date of PD-1 inhibitor, and VA site. Depending on PD-1 inhibitor administered, weight in kg was multiplied by 3 mg/kg or 2 mg/kg to obtain patient’s anticipated weight-based nivolumab and pembrolizumab dose, respectively. The calculated weight-based dose, fixed dose, and administered dose were compared to infer dosing strategy used at the time of ordering. If the patient’s weight-based dose was within 10% of the fixed dose, the order was categorized as converging because the doses were too similar to determine which dosing strategy was intended.

After determination of dosing strategy, the nivolumab orders were evaluated for actual vs missed cost savings. The cost-savings evaluation included only nivolumab orders because nivolumab is available in a 40-mg, 100-mg, and 240-mg vials and, therefore, has more potential for dose-rounding opportunities with minimal drug waste compared with pembrolizumab, which is available only in a 100-mg vial. Actual cost savings included patients who weighed ≤ 73.3 kg and received nivolumab dose based on 3 mg/kg or patients who weighed ≥ 86.7 kg and received nivolumab 240 mg (fixed dose). Missed cost savings comprised patients who weighed ≤ 73.3 kg who received 240 mg nivolumab or patients who weighed ≥ 86.7 kg and received a nivolumab dose > 240 mg. The cost difference between the dose given and theoretical cost-effective dose was calculated to determine actual and potential cost savings. Converging orders were not included in the cost-savings analysis as the intended nivolumab dose could not be determined. An additional cost analysis of nivolumab orders prescribed between September 1, 2016 and July 1, 2017 was also performed because nivolumab fixed dosing was FDA-approved for most solid tumor indications in September 2016.

To determine the incidence of immunemediated hypothyroidism for patients who received a dose of a PD-1 inhibitor at a VAMC, a CDW report with thyroid function laboratory values (TSH, T4, or T3), including reference range values based on specific VA site, and levothyroxine prescriptions issued during PD-1 inhibitor therapy was obtained. A patient was considered to have experienced immune-mediated hypothyroidism if the patient’s laboratory values demonstrated T4 below the LLN, TSH above the ULN, or if the medication fill history demonstrated levothyroxine initiation or a levothyroxine dose increase.

Results 

The CDW report identified 32,769 total PD-1 inhibitor orders. There were 3982 orders that did not meet inclusion criteria or inadequate data were obtained with CDW report and were excluded (Figure). The remaining 28,787 PD-1 inhibitor orders were evaluated for actual or missed cost savings. The distribution of dosing strategies can be found in Table 1.

Nivolumab accounted for 81.5% of all PD-1 inhibitor orders. Using the most cost-effective nivolumab dosing, the actual cost savings was estimated to be $8,514,300 with potential additional $5,591,250 of missed cost-savings opportunities. There were 8013 nivolumab orders written between September 1, 2016 and July 1, 2017. Cost-effective dosing was used in 4687 of these orders, which accounted for a cost savings of $5,198,570. The remaining 3326 orders had a missed cost-savings opportunity, which accounted for an additional $2,907,180 potential cost savings (Table 2).

PD-1 inhibitors were used for the treatment of 3249 unique patients. Based on abnormal thyroid function tests and levothyroxine initiation or dose increase, it is estimated that 514 (15.8%) patients experienced hypothyroidism during PD-1 inhibitor therapy. However, prior to PD-1 inhibitor therapy, 274 patients were receiving levothyroxine, suggesting baseline thyroid dysfunction. Of these patients, 152 (55.5%) patients maintained the same levothyroxine dose during PD-1 inhibitor therapy, but 91 (33.2%) required a levothyroxine dose increase. There were 187 patients who initiated levothyroxine during PD-1 inhibitor therapy (Table 3).

Discussion

Changes in FDA-approved dosing for PD-1 inhibitors allowed a combination of dosing strategies. Depending on patient weight, a weight-based or fixed-dosing strategy can be used to reduce drug cost while maintaining equivalent efficacy. This study evaluated use of dose rounding for PD-1 inhibitors within the VA health care system to identify actual and potential cost savings. To our knowledge, this is the first study to demonstrate cost savings through use of a combination of PD-1 inhibitor dosing strategies. Using CDW, researchers were able to review PD-1 dosing from all VAMCs and include a larger number of orders in a single retrospective study.

Nivolumab was the primary agent used within VAMCs. Depending on the indication, pembrolizumab requires PD-1 expression testing prior to its use in several solid tumor indications. Consequently, additional testing and patient eligibility is needed prior to use. Both PD-1 inhibitors were primarily dosed based on patient weight since this was the first FDAapproved dosing strategy. Nivolumab had more orders categorized as converging, which may be due to the therapeutic weight-based dose of 3 mg/kg for nivolumab vs 2 mg/kg for pembrolizumab. The calculated weight-based dose of nivolumab for an 80-kg patient is 240 mg, which also is the fixed dose. A 80-kg patient on pembrolizumab at 2 mg/kg would receive a 160-mg dose, whereas the fixed dose of pembrolizumab is 200 mg. Pembrolizumab is available only in a 100-mg vial, which limits opportunities for dose rounding without drug waste and could explain the higher amount of pembrolizumab orders in the fixed-dose category.

In this review of PD-1 inhibitor orders over approximately a 2.5-year study period, we identified $8,514,300 estimated cost savings with $5,591,250 estimated missed cost savings. When looking at orders administered after FDA approval for nivolumab-fixed dosing in September 2016, there was substantial cost savings of $5,198,570 with the potential for an additional $2,907,180 missed cost savings. Due to lower drug acquisition costs within the VA health care system, there may be higher cost-savings opportunities within other health care systems.

Through review of abnormal thyroid laboratory values and levothyroxine initiation or dose changes, this study estimated the incidence of hypothyroidism in patients receiving PD-1 inhibitor therapy at the VA. The incidence of primary hypothyroidism identified in this study was slightly higher at 15.8% compared with the 8.5 to 9.0% incidence reported from clinical trials.^1,2 There are several reasons why the incidence of hypothyroidism appeared higher in this study. Abnormal laboratory values were not assessed for the degree of deviation from the reference range; any TSH above the ULN, T4 below the LLN, or levothyroxine dose increase was included as thyroid dysfunction in this review. There is also the potential for endogenous age-related thyroid fluctuation, and the development of hypothyroidism may not have been related to PD-1 inhibitor therapy. Within this patient population, 8.4% were receiving levothyroxine prior to PD-1 inhibitor initiation indicating baseline thyroid dysfunction, and it is unclear whether levothyroxine dose increases were due to PD-1 inhibitor or endogenous fluctuation.

Limitations

There are several limitations to acknowledge. The dosing strategy and apparent dose rounding was determined by investigator inference and may not accurately represent the intended dosing strategy. This study did not address efficacy of PD-1 inhibitor and dosing strategy; however, clinical trials have demonstrated equivalent efficacy to generate the change in FDA-approved dosing. Additionally, FDA approval for nivolumab fixed dosing was indication specific. Starting in September 2016, many solid tumor indications had fixed dosing approved, but this approval was not necessarily all encompassing.

While the use of CDW allowed for a greater number of PD-1 inhibitor orders to be included in retrospective review, there also were limitations of the CDW report. The patient weight was limited to weight at time of therapy initiation. Due to the potential for weight changes, nivolumab dosing may have seemed inappropriate to investigators, and thereby excluded. Based on data available from CDW reports, hypothyroidism could not be graded according to NCI Common Terminology Criteria for Adverse Events, and the incidence of clinically significant hypothyroidism could not be determined.

Conclusions

With increasing drug acquisition costs, particularly among antineoplastic agents, health care systems frequently seek out cost-savings opportunities. Using a combination of weightbased and fixed-dosing strategies for PD-1 inhibitors can be a mechanism to achieve costsavings. Through the identification of the dosing strategy used for PD-1 inhibitors, we were able to identify and report instances for potential cost-savings opportunities among veterans treated within VA health care system. Use of CDW allows for data from all VAMCs to be evaluated in a single retrospective chart review, which allows for the inclusion of a larger sample size. This study identified a substantial cost savings for nivolumab through a combination of weight-based and fixed-dosing strategies. Due to the novel mechanism of action, ongoing realworld evaluation of adverse events and IrAEs is warranted.

Dosing strategies with nivolumab and pembrolizumab continue to evolve. In March 2018, nivolumab 480 mg IV every 4 weeks was FDA approved and in April 2020, pembrolizumab 400 mg IV every 6 weeks was FDA approved.^13,14 While the drug costs will remain the same, extended interval dosing strategies have cost avoidance such as fewer clinic appointments, resulting in decreased staffing costs and decreased patient travel. Additional studies will be needed to evaluate the cost and safety of the recently approved dosing strategies

Sickle cell disease (SCD) was associated with a greater than fourfold excess risk for COVID-19–related hospitalization and a greater than twofold risk for COVID-19–related death, according to a big-data analysis from the United Kingdom.

SCD was associated with an adjusted hazard ratio (HR) of 4.11 (95% confidence interval, 2.98-5.66) for admission to hospital and an HR of 2.55 (95% CI, 1.36-4.75) for death, report Ashley K. Clift, MBBS, a clinical research fellow at the University of Oxford, and colleagues. The results were published online July 20 in Annals of Internal Medicine.

Even those who carry just one copy of the sickle cell gene – the carrier status for sickle cell disease – appeared to be at heightened risk for these outcomes (HR for hospitalization, 1.38; 95% CI, 1.12-1.70; HR for death, 1.51; 95% CI, 1.13-2.00).

“Given the well-known ethnic patterning of sickle cell disorders, the predisposition they pose to other infections, and early evidence from smaller registries, we thought this would be an important analysis to run at the population level,” Dr. Clift said in an interview.

“Our data suggest that people living with sickle cell disorders are a group at higher risk from this infection, and this is important from a public health perspective in terms of vaccination strategies and advice on nonpharmacological interventions,” he said.

“The best course of action for managing risk in this group is vaccination,” said Enrico M. Novelli, MD, director of the adult sickle cell program at the University of Pittsburgh Medical Center. Dr. Novelli, who is also section chief of benign hematology in the university’s School of Medicine, was not involved in the study. “To date, there are no specific studies of the effect of COVID-19 vaccination in patients with SCD, but there is no reason to believe it would be less effective or more risky in this patient population,” he said.

In addition, common-sense measures, such as masking and physical distancing, particularly at large, indoor gatherings, should be encouraged, Dr. Novelli added. Keeping SCD under good control with available treatments is also important. “Any patient with SCD who contracts COVID-19 should undergo close, outpatient monitoring with pulse oxygen measurements. If sick, they should be hospitalized in a center familiar with the care of SCD patients.”

The U.K. results are in line with and expand on earlier evidence from specialist centers and registries, but the association with sickle cell trait has been unclear and is notable in these findings, Dr. Clift said.

“The finding of the association with sickle cell trait is somewhat unexpected,” pediatric hematologist/oncologist Rabi Hanna, MD, director of pediatric bone marrow transplantation at Cleveland Clinic Children’s, told this news organization. “But I would question the accuracy of the numbers, since not all people with the trait realize they have it. In other respects, the study confirms earlier hypotheses and data from single-center studies.” Dr. Hanna did not participate in the U.K. study.
 

Study details

The SCD cohort consisted of 5,059 persons with SCD and 25,682 carriers, those with just one copy of the trait. Data were drawn from the United Kingdom’s large primary-care QResearch database. Follow-up for hospitalizations was conducted from Jan. 24, 2020 to Sept. 30, 2020; follow-up for deaths was conducted from Jan. 24, 2020 to Jan. 18, 2021. Among adults with SCD, there were 40 hospitalizations and 10 deaths. Among those with sickle cell trait, there were 98 hospitalizations and 50 deaths. No children died, and only a few (<5) required hospitalization.

Previous registry research showed similarly elevated risks for severe disease and fatality among patients with SCD who were infected with SARS-CoV-2.

Because SCD affects 8 to 12 million people globally – 100,000 in the United States – the authors say their results are important for policymakers and for prioritizing vaccination. They also note that trait carriers may be underdiagnosed.

“While SCD is part of newborn screening, there may be undiagnosed older people with the trait in the general population, but it’s difficult to quantify how much this is undiagnosed,” Dr. Clift said. “But now we have these results, it’s not that surprising that sickle cell trait is also associated with increased risk, albeit to a lower extent. This could suggest an almost dose-like effect of the sickle mutations on COVID hospitalization risk.”

Neonatal screening for the most common form of SCD is currently mandatory in the United States, but the Centers for Disease Control and Prevention has no clear data on how many people are aware they are carriers, Dr. Hanna said. “The states didn’t all begin screening at the same time – some started in the 1990s, others started in the 2000s – so many young adults may be unaware they have the trait,” he said.

Dr. Clift said the multiorgan complications of SCD, such as cardiac and immune problems, may be contributing to the heightened risk in individuals infected with SARS-CoV-2. “For example, we know that people with sickle cell disease are more susceptible to other viral infections. There is also some pathophysiological overlap between SCD disease and severe COVID, such as clotting dysfunction, so that may be worth further exploration,” he said.

The overlapping clotting problems associated with both COVID-19 and SCD could increase the risk for severe venous thromboembolism. In addition, experts noted that patients with SCD often have pre-COVID endothelial damage and baseline inflammation and are very sensitive to hypoxia; as well, a sizable proportion have lung disease.

The message to patients and physicians counseling patients is twofold, said Dr. Hanna: “SCD patients are at higher risk of COVID complications, and these are preventable with vaccination.”

The study was supported by the UK Medical Research Council. Dr. Clift is supported by Cancer Research UK. Coauthor Dr. Hippisley-Cox has received fees from ClinRisk and nonfinancial support from QResearch outside of the submitted work. Dr. Hanna has disclosed no relevant financial relationships. Dr. Novelli is a consultant for Novartis.

A version of this article first appeared on Medscape.com.

Sickle cell disease (SCD) was associated with a greater than fourfold excess risk for COVID-19–related hospitalization and a greater than twofold risk for COVID-19–related death, according to a big-data analysis from the United Kingdom.

SCD was associated with an adjusted hazard ratio (HR) of 4.11 (95% confidence interval, 2.98-5.66) for admission to hospital and an HR of 2.55 (95% CI, 1.36-4.75) for death, report Ashley K. Clift, MBBS, a clinical research fellow at the University of Oxford, and colleagues. The results were published online July 20 in Annals of Internal Medicine.

Even those who carry just one copy of the sickle cell gene – the carrier status for sickle cell disease – appeared to be at heightened risk for these outcomes (HR for hospitalization, 1.38; 95% CI, 1.12-1.70; HR for death, 1.51; 95% CI, 1.13-2.00).

“Given the well-known ethnic patterning of sickle cell disorders, the predisposition they pose to other infections, and early evidence from smaller registries, we thought this would be an important analysis to run at the population level,” Dr. Clift said in an interview.

“Our data suggest that people living with sickle cell disorders are a group at higher risk from this infection, and this is important from a public health perspective in terms of vaccination strategies and advice on nonpharmacological interventions,” he said.

“The best course of action for managing risk in this group is vaccination,” said Enrico M. Novelli, MD, director of the adult sickle cell program at the University of Pittsburgh Medical Center. Dr. Novelli, who is also section chief of benign hematology in the university’s School of Medicine, was not involved in the study. “To date, there are no specific studies of the effect of COVID-19 vaccination in patients with SCD, but there is no reason to believe it would be less effective or more risky in this patient population,” he said.

In addition, common-sense measures, such as masking and physical distancing, particularly at large, indoor gatherings, should be encouraged, Dr. Novelli added. Keeping SCD under good control with available treatments is also important. “Any patient with SCD who contracts COVID-19 should undergo close, outpatient monitoring with pulse oxygen measurements. If sick, they should be hospitalized in a center familiar with the care of SCD patients.”

The U.K. results are in line with and expand on earlier evidence from specialist centers and registries, but the association with sickle cell trait has been unclear and is notable in these findings, Dr. Clift said.

“The finding of the association with sickle cell trait is somewhat unexpected,” pediatric hematologist/oncologist Rabi Hanna, MD, director of pediatric bone marrow transplantation at Cleveland Clinic Children’s, told this news organization. “But I would question the accuracy of the numbers, since not all people with the trait realize they have it. In other respects, the study confirms earlier hypotheses and data from single-center studies.” Dr. Hanna did not participate in the U.K. study.
 

Study details

The SCD cohort consisted of 5,059 persons with SCD and 25,682 carriers, those with just one copy of the trait. Data were drawn from the United Kingdom’s large primary-care QResearch database. Follow-up for hospitalizations was conducted from Jan. 24, 2020 to Sept. 30, 2020; follow-up for deaths was conducted from Jan. 24, 2020 to Jan. 18, 2021. Among adults with SCD, there were 40 hospitalizations and 10 deaths. Among those with sickle cell trait, there were 98 hospitalizations and 50 deaths. No children died, and only a few (<5) required hospitalization.

Previous registry research showed similarly elevated risks for severe disease and fatality among patients with SCD who were infected with SARS-CoV-2.

Because SCD affects 8 to 12 million people globally – 100,000 in the United States – the authors say their results are important for policymakers and for prioritizing vaccination. They also note that trait carriers may be underdiagnosed.

“While SCD is part of newborn screening, there may be undiagnosed older people with the trait in the general population, but it’s difficult to quantify how much this is undiagnosed,” Dr. Clift said. “But now we have these results, it’s not that surprising that sickle cell trait is also associated with increased risk, albeit to a lower extent. This could suggest an almost dose-like effect of the sickle mutations on COVID hospitalization risk.”

Neonatal screening for the most common form of SCD is currently mandatory in the United States, but the Centers for Disease Control and Prevention has no clear data on how many people are aware they are carriers, Dr. Hanna said. “The states didn’t all begin screening at the same time – some started in the 1990s, others started in the 2000s – so many young adults may be unaware they have the trait,” he said.

Dr. Clift said the multiorgan complications of SCD, such as cardiac and immune problems, may be contributing to the heightened risk in individuals infected with SARS-CoV-2. “For example, we know that people with sickle cell disease are more susceptible to other viral infections. There is also some pathophysiological overlap between SCD disease and severe COVID, such as clotting dysfunction, so that may be worth further exploration,” he said.

The overlapping clotting problems associated with both COVID-19 and SCD could increase the risk for severe venous thromboembolism. In addition, experts noted that patients with SCD often have pre-COVID endothelial damage and baseline inflammation and are very sensitive to hypoxia; as well, a sizable proportion have lung disease.

The message to patients and physicians counseling patients is twofold, said Dr. Hanna: “SCD patients are at higher risk of COVID complications, and these are preventable with vaccination.”

The study was supported by the UK Medical Research Council. Dr. Clift is supported by Cancer Research UK. Coauthor Dr. Hippisley-Cox has received fees from ClinRisk and nonfinancial support from QResearch outside of the submitted work. Dr. Hanna has disclosed no relevant financial relationships. Dr. Novelli is a consultant for Novartis.

A version of this article first appeared on Medscape.com.

Sickle cell disease (SCD) was associated with a greater than fourfold excess risk for COVID-19–related hospitalization and a greater than twofold risk for COVID-19–related death, according to a big-data analysis from the United Kingdom.

SCD was associated with an adjusted hazard ratio (HR) of 4.11 (95% confidence interval, 2.98-5.66) for admission to hospital and an HR of 2.55 (95% CI, 1.36-4.75) for death, report Ashley K. Clift, MBBS, a clinical research fellow at the University of Oxford, and colleagues. The results were published online July 20 in Annals of Internal Medicine.

Even those who carry just one copy of the sickle cell gene – the carrier status for sickle cell disease – appeared to be at heightened risk for these outcomes (HR for hospitalization, 1.38; 95% CI, 1.12-1.70; HR for death, 1.51; 95% CI, 1.13-2.00).

“Given the well-known ethnic patterning of sickle cell disorders, the predisposition they pose to other infections, and early evidence from smaller registries, we thought this would be an important analysis to run at the population level,” Dr. Clift said in an interview.

“Our data suggest that people living with sickle cell disorders are a group at higher risk from this infection, and this is important from a public health perspective in terms of vaccination strategies and advice on nonpharmacological interventions,” he said.

“The best course of action for managing risk in this group is vaccination,” said Enrico M. Novelli, MD, director of the adult sickle cell program at the University of Pittsburgh Medical Center. Dr. Novelli, who is also section chief of benign hematology in the university’s School of Medicine, was not involved in the study. “To date, there are no specific studies of the effect of COVID-19 vaccination in patients with SCD, but there is no reason to believe it would be less effective or more risky in this patient population,” he said.

In addition, common-sense measures, such as masking and physical distancing, particularly at large, indoor gatherings, should be encouraged, Dr. Novelli added. Keeping SCD under good control with available treatments is also important. “Any patient with SCD who contracts COVID-19 should undergo close, outpatient monitoring with pulse oxygen measurements. If sick, they should be hospitalized in a center familiar with the care of SCD patients.”

The U.K. results are in line with and expand on earlier evidence from specialist centers and registries, but the association with sickle cell trait has been unclear and is notable in these findings, Dr. Clift said.

“The finding of the association with sickle cell trait is somewhat unexpected,” pediatric hematologist/oncologist Rabi Hanna, MD, director of pediatric bone marrow transplantation at Cleveland Clinic Children’s, told this news organization. “But I would question the accuracy of the numbers, since not all people with the trait realize they have it. In other respects, the study confirms earlier hypotheses and data from single-center studies.” Dr. Hanna did not participate in the U.K. study.
 

Study details

The SCD cohort consisted of 5,059 persons with SCD and 25,682 carriers, those with just one copy of the trait. Data were drawn from the United Kingdom’s large primary-care QResearch database. Follow-up for hospitalizations was conducted from Jan. 24, 2020 to Sept. 30, 2020; follow-up for deaths was conducted from Jan. 24, 2020 to Jan. 18, 2021. Among adults with SCD, there were 40 hospitalizations and 10 deaths. Among those with sickle cell trait, there were 98 hospitalizations and 50 deaths. No children died, and only a few (<5) required hospitalization.

Previous registry research showed similarly elevated risks for severe disease and fatality among patients with SCD who were infected with SARS-CoV-2.

Because SCD affects 8 to 12 million people globally – 100,000 in the United States – the authors say their results are important for policymakers and for prioritizing vaccination. They also note that trait carriers may be underdiagnosed.

“While SCD is part of newborn screening, there may be undiagnosed older people with the trait in the general population, but it’s difficult to quantify how much this is undiagnosed,” Dr. Clift said. “But now we have these results, it’s not that surprising that sickle cell trait is also associated with increased risk, albeit to a lower extent. This could suggest an almost dose-like effect of the sickle mutations on COVID hospitalization risk.”

Neonatal screening for the most common form of SCD is currently mandatory in the United States, but the Centers for Disease Control and Prevention has no clear data on how many people are aware they are carriers, Dr. Hanna said. “The states didn’t all begin screening at the same time – some started in the 1990s, others started in the 2000s – so many young adults may be unaware they have the trait,” he said.

Dr. Clift said the multiorgan complications of SCD, such as cardiac and immune problems, may be contributing to the heightened risk in individuals infected with SARS-CoV-2. “For example, we know that people with sickle cell disease are more susceptible to other viral infections. There is also some pathophysiological overlap between SCD disease and severe COVID, such as clotting dysfunction, so that may be worth further exploration,” he said.

The overlapping clotting problems associated with both COVID-19 and SCD could increase the risk for severe venous thromboembolism. In addition, experts noted that patients with SCD often have pre-COVID endothelial damage and baseline inflammation and are very sensitive to hypoxia; as well, a sizable proportion have lung disease.

The message to patients and physicians counseling patients is twofold, said Dr. Hanna: “SCD patients are at higher risk of COVID complications, and these are preventable with vaccination.”

The study was supported by the UK Medical Research Council. Dr. Clift is supported by Cancer Research UK. Coauthor Dr. Hippisley-Cox has received fees from ClinRisk and nonfinancial support from QResearch outside of the submitted work. Dr. Hanna has disclosed no relevant financial relationships. Dr. Novelli is a consultant for Novartis.

A version of this article first appeared on Medscape.com.