Federal Practitioner

WASHINGTON, DC – A mouth rinse used to identify oral microbiome composition could serve as an early-detection tool for gastric cancer, new evidence suggests.

Researchers found distinct bacterial composition differences in patient samples that point to the potential for oral microbial signatures to be used as biomarkers for assessing gastric cancer risk. 

“Too many patients are being diagnosed too late. There are no formal screening guidelines for gastric cancer, and more than half of patients with gastric cancer do not receive a diagnosis until their cancer is already at an advanced stage,” said Shruthi Reddy Perati, MD, a general surgery resident at Rutgers University Robert Wood Johnson School of Medicine in New Brunswick, New Jersey.

Detecting gastric cancer now generally requires an invasive procedure, such as endoscopy. Therefore, a noninvasive “swish and spit” test could be more accessible and allow for more widespread screening, Dr. Perati said at a May 8 press briefing during which her research (Abstract 949) was previewed for Digestive Disease Week^® (DDW).

Gastric cancer, also known as stomach cancer, is the fourth most common cause of cancer-related death in the world. The United States can expect 26,890 new cases and 10,880 deaths from this type of cancer in 2024, the American Cancer Society estimates.
 

Microbial Signatures Found

Dr. Perati and colleagues collected oral rinse samples from 98 patients: 30 known to have gastric cancer , 30 with precancerous gastric conditions (pre–gastric cancer), and 38 control participants without pre-gastric or gastric cancer. Sixty-two percent were women, 32% were Hispanic, 31% had diabetes, and 18% were smokers.

The researchers analyzed the samples for alpha and beta diversity and conducted differential analysis using the framework called analysis of compositions of microbiomes.

They found distinct differences between the oral microbiomes of the healthy group and those of the groups with gastric cancer and pre–gastric cancer. In addition, the microbiomes of participants with cancer and of those with precancerous conditions were similar.

The results suggest that the microbiome changes may occur as soon as the stomach environment starts to undergo changes that can eventually turn into cancer.

“The oral microbiome may serve as a window into the composition of the stomach environment,” Dr. Perati said.

The investigators created a screening model to detect the most relevant 13 bacterial genera that differed between the control group and the gastric cancer and pre–gastric cancer groups. The tenfold cross-validation model demonstrated good ability to discriminate using bacteria alone (area under the curve [AUC], 0.74) and was further improved with the addition of clinical variables, including demographics and comorbidities (AUC, 0.91), the researchers noted.

As the investigators noted, the model’s performance improved with the addition of clinical variables, said Loren Laine, MD, professor of medicine (digestive diseases) at Yale School of Medicine and chair of DDW 2024.

An AUC of 0.74 using bacteria alone, which increased to 0.91 by adding demographics and comorbidities, “[is] starting to be really meaningful,” Dr. Laine said.

Further studies should evaluate the test’s sensitivity and specificity, Dr. Laine added.
 

Additional Considerations

The microbiome can vary between people and within the same individual over time. Probiotics, antibiotics, and diet can lead to changes in the microbiome, Dr. Perati said.

When asked how these changes could affect the accuracy of an oral rinse test, Dr. Perati said “it’s known that, in general, dietary modifications can have an impact on the diversity and the prevalence of certain bacteria throughout the GI tract.”

Though variance is expected, we’re hoping to see that the differences in the microbiome composition between the malignant groups and the control groups are more significant than those lower-level background changes due to dietary modifications, for example, she added.

The research is in its early days, and the results need to be validated in a larger study, Dr. Perati said.

Ninety-eight patients is “still a very small number,” said Dr. Laine, who co-moderated the press briefing. “More research is needed.”

Still, the study “has huge implications that could eventually lead to the development of noninvasive and accessible early screening for gastric cancer,” she said.

Dr. Perati and Dr. Laine reported no relevant financial relationships. The study was independently supported.

A version of this article appeared on Medscape.com.

WASHINGTON, DC – A mouth rinse used to identify oral microbiome composition could serve as an early-detection tool for gastric cancer, new evidence suggests.

Researchers found distinct bacterial composition differences in patient samples that point to the potential for oral microbial signatures to be used as biomarkers for assessing gastric cancer risk. 

“Too many patients are being diagnosed too late. There are no formal screening guidelines for gastric cancer, and more than half of patients with gastric cancer do not receive a diagnosis until their cancer is already at an advanced stage,” said Shruthi Reddy Perati, MD, a general surgery resident at Rutgers University Robert Wood Johnson School of Medicine in New Brunswick, New Jersey.

Detecting gastric cancer now generally requires an invasive procedure, such as endoscopy. Therefore, a noninvasive “swish and spit” test could be more accessible and allow for more widespread screening, Dr. Perati said at a May 8 press briefing during which her research (Abstract 949) was previewed for Digestive Disease Week^® (DDW).

Gastric cancer, also known as stomach cancer, is the fourth most common cause of cancer-related death in the world. The United States can expect 26,890 new cases and 10,880 deaths from this type of cancer in 2024, the American Cancer Society estimates.
 

Microbial Signatures Found

Dr. Perati and colleagues collected oral rinse samples from 98 patients: 30 known to have gastric cancer , 30 with precancerous gastric conditions (pre–gastric cancer), and 38 control participants without pre-gastric or gastric cancer. Sixty-two percent were women, 32% were Hispanic, 31% had diabetes, and 18% were smokers.

The researchers analyzed the samples for alpha and beta diversity and conducted differential analysis using the framework called analysis of compositions of microbiomes.

They found distinct differences between the oral microbiomes of the healthy group and those of the groups with gastric cancer and pre–gastric cancer. In addition, the microbiomes of participants with cancer and of those with precancerous conditions were similar.

The results suggest that the microbiome changes may occur as soon as the stomach environment starts to undergo changes that can eventually turn into cancer.

“The oral microbiome may serve as a window into the composition of the stomach environment,” Dr. Perati said.

The investigators created a screening model to detect the most relevant 13 bacterial genera that differed between the control group and the gastric cancer and pre–gastric cancer groups. The tenfold cross-validation model demonstrated good ability to discriminate using bacteria alone (area under the curve [AUC], 0.74) and was further improved with the addition of clinical variables, including demographics and comorbidities (AUC, 0.91), the researchers noted.

As the investigators noted, the model’s performance improved with the addition of clinical variables, said Loren Laine, MD, professor of medicine (digestive diseases) at Yale School of Medicine and chair of DDW 2024.

An AUC of 0.74 using bacteria alone, which increased to 0.91 by adding demographics and comorbidities, “[is] starting to be really meaningful,” Dr. Laine said.

Further studies should evaluate the test’s sensitivity and specificity, Dr. Laine added.
 

Additional Considerations

The microbiome can vary between people and within the same individual over time. Probiotics, antibiotics, and diet can lead to changes in the microbiome, Dr. Perati said.

When asked how these changes could affect the accuracy of an oral rinse test, Dr. Perati said “it’s known that, in general, dietary modifications can have an impact on the diversity and the prevalence of certain bacteria throughout the GI tract.”

Though variance is expected, we’re hoping to see that the differences in the microbiome composition between the malignant groups and the control groups are more significant than those lower-level background changes due to dietary modifications, for example, she added.

The research is in its early days, and the results need to be validated in a larger study, Dr. Perati said.

Ninety-eight patients is “still a very small number,” said Dr. Laine, who co-moderated the press briefing. “More research is needed.”

Still, the study “has huge implications that could eventually lead to the development of noninvasive and accessible early screening for gastric cancer,” she said.

Dr. Perati and Dr. Laine reported no relevant financial relationships. The study was independently supported.

A version of this article appeared on Medscape.com.

WASHINGTON, DC – A mouth rinse used to identify oral microbiome composition could serve as an early-detection tool for gastric cancer, new evidence suggests.

Researchers found distinct bacterial composition differences in patient samples that point to the potential for oral microbial signatures to be used as biomarkers for assessing gastric cancer risk. 

“Too many patients are being diagnosed too late. There are no formal screening guidelines for gastric cancer, and more than half of patients with gastric cancer do not receive a diagnosis until their cancer is already at an advanced stage,” said Shruthi Reddy Perati, MD, a general surgery resident at Rutgers University Robert Wood Johnson School of Medicine in New Brunswick, New Jersey.

Detecting gastric cancer now generally requires an invasive procedure, such as endoscopy. Therefore, a noninvasive “swish and spit” test could be more accessible and allow for more widespread screening, Dr. Perati said at a May 8 press briefing during which her research (Abstract 949) was previewed for Digestive Disease Week^® (DDW).

Gastric cancer, also known as stomach cancer, is the fourth most common cause of cancer-related death in the world. The United States can expect 26,890 new cases and 10,880 deaths from this type of cancer in 2024, the American Cancer Society estimates.
 

Microbial Signatures Found

Dr. Perati and colleagues collected oral rinse samples from 98 patients: 30 known to have gastric cancer , 30 with precancerous gastric conditions (pre–gastric cancer), and 38 control participants without pre-gastric or gastric cancer. Sixty-two percent were women, 32% were Hispanic, 31% had diabetes, and 18% were smokers.

The researchers analyzed the samples for alpha and beta diversity and conducted differential analysis using the framework called analysis of compositions of microbiomes.

They found distinct differences between the oral microbiomes of the healthy group and those of the groups with gastric cancer and pre–gastric cancer. In addition, the microbiomes of participants with cancer and of those with precancerous conditions were similar.

The results suggest that the microbiome changes may occur as soon as the stomach environment starts to undergo changes that can eventually turn into cancer.

“The oral microbiome may serve as a window into the composition of the stomach environment,” Dr. Perati said.

The investigators created a screening model to detect the most relevant 13 bacterial genera that differed between the control group and the gastric cancer and pre–gastric cancer groups. The tenfold cross-validation model demonstrated good ability to discriminate using bacteria alone (area under the curve [AUC], 0.74) and was further improved with the addition of clinical variables, including demographics and comorbidities (AUC, 0.91), the researchers noted.

As the investigators noted, the model’s performance improved with the addition of clinical variables, said Loren Laine, MD, professor of medicine (digestive diseases) at Yale School of Medicine and chair of DDW 2024.

An AUC of 0.74 using bacteria alone, which increased to 0.91 by adding demographics and comorbidities, “[is] starting to be really meaningful,” Dr. Laine said.

Further studies should evaluate the test’s sensitivity and specificity, Dr. Laine added.
 

Additional Considerations

The microbiome can vary between people and within the same individual over time. Probiotics, antibiotics, and diet can lead to changes in the microbiome, Dr. Perati said.

When asked how these changes could affect the accuracy of an oral rinse test, Dr. Perati said “it’s known that, in general, dietary modifications can have an impact on the diversity and the prevalence of certain bacteria throughout the GI tract.”

Though variance is expected, we’re hoping to see that the differences in the microbiome composition between the malignant groups and the control groups are more significant than those lower-level background changes due to dietary modifications, for example, she added.

The research is in its early days, and the results need to be validated in a larger study, Dr. Perati said.

Ninety-eight patients is “still a very small number,” said Dr. Laine, who co-moderated the press briefing. “More research is needed.”

Still, the study “has huge implications that could eventually lead to the development of noninvasive and accessible early screening for gastric cancer,” she said.

Dr. Perati and Dr. Laine reported no relevant financial relationships. The study was independently supported.

A version of this article appeared on Medscape.com.

TOPLINE:

A hypofractionated intensity-modulated radiotherapy (IMRT) may be safe and well-tolerated in women with cervical cancer undergoing pelvic irradiation with concurrent chemotherapy following surgical resection, results from the phase 2 POHIM-CCRT trial suggested.

METHODOLOGY:

• To date, no studies have assessed the treatment outcomes and toxic effects of hypofractionated IMRT following radical hysterectomy in patients with cervical cancer undergoing curative radiotherapy.
• The team analyzed outcomes from 79 patients undergoing hypofractionated IMRT for cervical cancer after radical hysterectomy and pelvic lymph node dissection.
• Patients were a median age of 48; 29.5% had stage IB to IIA disease, another 29.5% had stage IIB disease, and 41% had stage III disease. Patients also had at least one of the following criteria following radical hysterectomy and pelvic lymph node dissection: lymph node metastasis (39.7%), parametrial invasion (54.4%), and positive resection margin (5.1%).
• The prescribed dose to the planning target volume was 40 Gy, delivered in 16 fractions to the whole pelvis, with any type of IMRT permitted. Overall, 71 patients also underwent concurrent weekly cisplatin (40 mg/m² of body surface area for three cycles), and eight received fluorouracil (1000 mg/m² on days 1-5) with cisplatin (60 mg/m² for two cycles).
• The primary endpoint was the incidence of acute grade 3 or higher gastrointestinal tract, genitourinary, and hematologic toxic effects during radiotherapy or within 3 months of completing radiotherapy.

TAKEAWAY:

• After radiotherapy, only two patients (2.5%) experienced acute grade 3 or higher toxic effects. One was hospitalized for enterocolitis on the last day of radiotherapy and developed grade 3 anemia 3 months after completing radiotherapy; the other experienced hematologic toxic effects and also developed grade 3 anemia 3 months after completing radiotherapy.
• No patients experienced late grade 3 or higher toxic effects.
• When assessing toxic effects of any grade, acute and late gastrointestinal tract toxicities occurred in 76% and 31.6% of patients, respectively; acute and late genitourinary toxicities, all grade 1, occurred in 19% and 24.1% of patients, respectively; and hematologic toxicities occurred in 29.1% and 6.3% of patients, respectively.
• Overall, at 3 years, 79.3% of patients were disease-free and 98% were alive. After a median follow-up of 43 months, 16 patients (20.3%) experienced disease recurrence, four of whom were salvaged and three of whom died.

IN PRACTICE:

“This nonrandomized controlled trial is the first prospective trial, to our knowledge, to show acceptable acute toxic effects of hypofractionated IMRT for cervical cancer in a postoperative concurrent chemoradiotherapy setting,” the authors said, adding that the rate of grade 3 or higher acute toxic effects of 2.5% reported in this study was “substantially lower than our initial hypothesis of less than 15%.”

However , in an accompanying editorial, Mark E. Bernard, MD, of the University of Kentucky College of Medicine, Lexington, highlighted caveats to the study design and raised two core questions: “Should acute toxic effects be the primary endpoint of a single-group, phase 2 study using hypofractionation with fewer cycles of concurrent chemotherapy? Should the primary endpoint rather have been a cancer control endpoint, such as disease-free survival, overall survival, or local control?”

Still, Dr. Bernard wrote, “This trial does help lay the foundation for future pelvic hypofractionated trials with concurrent chemotherapy, especially for gynecological malignant tumors.”

SOURCE:

The research, led by Won Park, MD, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea, was published in JAMA Oncology.

LIMITATIONS:

The trial is a single-arm study, with a short follow-up time. In the editorial, Bernard listed several limitations, including the fact that patients received fewer cycles of concurrent chemotherapy than what’s typically given in this population.

DISCLOSURES:

No funding or relevant financial relationships were declared.

A version of this article appeared on Medscape.com.

TOPLINE:

A hypofractionated intensity-modulated radiotherapy (IMRT) may be safe and well-tolerated in women with cervical cancer undergoing pelvic irradiation with concurrent chemotherapy following surgical resection, results from the phase 2 POHIM-CCRT trial suggested.

METHODOLOGY:

• To date, no studies have assessed the treatment outcomes and toxic effects of hypofractionated IMRT following radical hysterectomy in patients with cervical cancer undergoing curative radiotherapy.
• The team analyzed outcomes from 79 patients undergoing hypofractionated IMRT for cervical cancer after radical hysterectomy and pelvic lymph node dissection.
• Patients were a median age of 48; 29.5% had stage IB to IIA disease, another 29.5% had stage IIB disease, and 41% had stage III disease. Patients also had at least one of the following criteria following radical hysterectomy and pelvic lymph node dissection: lymph node metastasis (39.7%), parametrial invasion (54.4%), and positive resection margin (5.1%).
• The prescribed dose to the planning target volume was 40 Gy, delivered in 16 fractions to the whole pelvis, with any type of IMRT permitted. Overall, 71 patients also underwent concurrent weekly cisplatin (40 mg/m² of body surface area for three cycles), and eight received fluorouracil (1000 mg/m² on days 1-5) with cisplatin (60 mg/m² for two cycles).
• The primary endpoint was the incidence of acute grade 3 or higher gastrointestinal tract, genitourinary, and hematologic toxic effects during radiotherapy or within 3 months of completing radiotherapy.

TAKEAWAY:

• After radiotherapy, only two patients (2.5%) experienced acute grade 3 or higher toxic effects. One was hospitalized for enterocolitis on the last day of radiotherapy and developed grade 3 anemia 3 months after completing radiotherapy; the other experienced hematologic toxic effects and also developed grade 3 anemia 3 months after completing radiotherapy.
• No patients experienced late grade 3 or higher toxic effects.
• When assessing toxic effects of any grade, acute and late gastrointestinal tract toxicities occurred in 76% and 31.6% of patients, respectively; acute and late genitourinary toxicities, all grade 1, occurred in 19% and 24.1% of patients, respectively; and hematologic toxicities occurred in 29.1% and 6.3% of patients, respectively.
• Overall, at 3 years, 79.3% of patients were disease-free and 98% were alive. After a median follow-up of 43 months, 16 patients (20.3%) experienced disease recurrence, four of whom were salvaged and three of whom died.

IN PRACTICE:

“This nonrandomized controlled trial is the first prospective trial, to our knowledge, to show acceptable acute toxic effects of hypofractionated IMRT for cervical cancer in a postoperative concurrent chemoradiotherapy setting,” the authors said, adding that the rate of grade 3 or higher acute toxic effects of 2.5% reported in this study was “substantially lower than our initial hypothesis of less than 15%.”

However , in an accompanying editorial, Mark E. Bernard, MD, of the University of Kentucky College of Medicine, Lexington, highlighted caveats to the study design and raised two core questions: “Should acute toxic effects be the primary endpoint of a single-group, phase 2 study using hypofractionation with fewer cycles of concurrent chemotherapy? Should the primary endpoint rather have been a cancer control endpoint, such as disease-free survival, overall survival, or local control?”

Still, Dr. Bernard wrote, “This trial does help lay the foundation for future pelvic hypofractionated trials with concurrent chemotherapy, especially for gynecological malignant tumors.”

SOURCE:

The research, led by Won Park, MD, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea, was published in JAMA Oncology.

LIMITATIONS:

The trial is a single-arm study, with a short follow-up time. In the editorial, Bernard listed several limitations, including the fact that patients received fewer cycles of concurrent chemotherapy than what’s typically given in this population.

DISCLOSURES:

No funding or relevant financial relationships were declared.

A version of this article appeared on Medscape.com.

TOPLINE:

A hypofractionated intensity-modulated radiotherapy (IMRT) may be safe and well-tolerated in women with cervical cancer undergoing pelvic irradiation with concurrent chemotherapy following surgical resection, results from the phase 2 POHIM-CCRT trial suggested.

METHODOLOGY:

• To date, no studies have assessed the treatment outcomes and toxic effects of hypofractionated IMRT following radical hysterectomy in patients with cervical cancer undergoing curative radiotherapy.
• The team analyzed outcomes from 79 patients undergoing hypofractionated IMRT for cervical cancer after radical hysterectomy and pelvic lymph node dissection.
• Patients were a median age of 48; 29.5% had stage IB to IIA disease, another 29.5% had stage IIB disease, and 41% had stage III disease. Patients also had at least one of the following criteria following radical hysterectomy and pelvic lymph node dissection: lymph node metastasis (39.7%), parametrial invasion (54.4%), and positive resection margin (5.1%).
• The prescribed dose to the planning target volume was 40 Gy, delivered in 16 fractions to the whole pelvis, with any type of IMRT permitted. Overall, 71 patients also underwent concurrent weekly cisplatin (40 mg/m² of body surface area for three cycles), and eight received fluorouracil (1000 mg/m² on days 1-5) with cisplatin (60 mg/m² for two cycles).
• The primary endpoint was the incidence of acute grade 3 or higher gastrointestinal tract, genitourinary, and hematologic toxic effects during radiotherapy or within 3 months of completing radiotherapy.

TAKEAWAY:

• After radiotherapy, only two patients (2.5%) experienced acute grade 3 or higher toxic effects. One was hospitalized for enterocolitis on the last day of radiotherapy and developed grade 3 anemia 3 months after completing radiotherapy; the other experienced hematologic toxic effects and also developed grade 3 anemia 3 months after completing radiotherapy.
• No patients experienced late grade 3 or higher toxic effects.
• When assessing toxic effects of any grade, acute and late gastrointestinal tract toxicities occurred in 76% and 31.6% of patients, respectively; acute and late genitourinary toxicities, all grade 1, occurred in 19% and 24.1% of patients, respectively; and hematologic toxicities occurred in 29.1% and 6.3% of patients, respectively.
• Overall, at 3 years, 79.3% of patients were disease-free and 98% were alive. After a median follow-up of 43 months, 16 patients (20.3%) experienced disease recurrence, four of whom were salvaged and three of whom died.

IN PRACTICE:

“This nonrandomized controlled trial is the first prospective trial, to our knowledge, to show acceptable acute toxic effects of hypofractionated IMRT for cervical cancer in a postoperative concurrent chemoradiotherapy setting,” the authors said, adding that the rate of grade 3 or higher acute toxic effects of 2.5% reported in this study was “substantially lower than our initial hypothesis of less than 15%.”

However , in an accompanying editorial, Mark E. Bernard, MD, of the University of Kentucky College of Medicine, Lexington, highlighted caveats to the study design and raised two core questions: “Should acute toxic effects be the primary endpoint of a single-group, phase 2 study using hypofractionation with fewer cycles of concurrent chemotherapy? Should the primary endpoint rather have been a cancer control endpoint, such as disease-free survival, overall survival, or local control?”

Still, Dr. Bernard wrote, “This trial does help lay the foundation for future pelvic hypofractionated trials with concurrent chemotherapy, especially for gynecological malignant tumors.”

SOURCE:

The research, led by Won Park, MD, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea, was published in JAMA Oncology.

LIMITATIONS:

The trial is a single-arm study, with a short follow-up time. In the editorial, Bernard listed several limitations, including the fact that patients received fewer cycles of concurrent chemotherapy than what’s typically given in this population.

DISCLOSURES:

No funding or relevant financial relationships were declared.

A version of this article appeared on Medscape.com.

BERLIN — To date, mRNA vaccines have had their largest global presence in combating the COVID-19 pandemic. Intensive research is underway on many other potential applications for this vaccine technology, which suggests a promising future. Martina Prelog, MD, a pediatric and adolescent medicine specialist at the University Hospital of Würzburg in Germany, reported on the principles, research status, and perspectives for these vaccines at the 25th Travel and Health Forum of the Center for Travel Medicine in Berlin.

To understand the future, the immunologist first examined the past. “The induction of cellular and humoral immune responses by externally injected mRNA was discovered in the 1990s,” she said.
 

Instability Challenge

Significant hurdles in mRNA vaccinations included the instability of mRNA and the immune system’s ability to identify foreign mRNA as a threat and destroy mRNA fragments. “The breakthrough toward vaccination came through Dr. Katalin Karikó, who, along with Dr. Drew Weissman, both of the University of Pennsylvania School of Medicine, discovered in 2005 that modifications of mRNA (replacing the nucleoside uridine with pseudouridine) enable better stability of mRNA, reduced immunogenicity, and higher translational capacity at the ribosomes,” said Dr. Prelog.

With this discovery, the two researchers paved the way for the development of mRNA vaccines against COVID-19 and other diseases. They were awarded the Nobel Prize in medicine for their discovery last year.
 

Improved Scalability

“Since 2009, mRNA vaccines have been studied as a treatment option for cancer,” said Dr. Prelog. “Since 2012, they have been studied for the influenza virus and respiratory syncytial virus [RSV].” Consequently, several mRNA vaccines are currently in development or in approval studies. “The mRNA technology offers the advantage of quickly and flexibly responding to new variants of pathogens and the ability to scale up production when there is high demand for a particular vaccine.”

Different forms and designations of mRNA vaccines are used, depending on the application and desired effect, said Dr. Prelog.

In nucleoside-modified mRNA vaccines, modifications in the mRNA sequence enable the mRNA to remain in the body longer and to induce protein synthesis more effectively.

Lipid nanoparticle (LNP)–encapsulated mRNA vaccines protect the coding mRNA sequences against degradation by the body’s enzymes and facilitate the uptake of mRNA into cells, where it then triggers the production of the desired protein. In addition, LNPs are involved in cell stimulation and support the self-adjuvant effect of mRNA vaccines, thus eliminating the need for adjuvants.

Self-amplifying mRNA vaccines include a special mRNA that replicates itself in the cell and contains a sequence for RNA replicase, in addition to the coding sequence for the protein. This composition enables increased production of the target protein without the need for a high amount of external mRNA administration. Such vaccines could trigger a longer and stronger immune response because the immune system has more time to interact with the protein.
 

Cancer Immunotherapy

Dr. Prelog also discussed personalized vaccines for cancer immunotherapy. Personalized mRNA vaccines are tailored to the patient’s genetic characteristics and antigens. They could be used in cancer immunotherapy to activate the immune system selectively against tumor cells.

Multivalent mRNA vaccines contain mRNA that codes for multiple antigens rather than just one protein to generate an immune response. These vaccines could be particularly useful in fighting pathogens with variable or changing surface structures or in eliciting protection against multiple pathogens simultaneously.

The technology of mRNA-encoded antibodies involves introducing mRNA into the cell, which creates light and heavy chains of antibodies. This step leads to the formation of antibodies targeted against toxins (eg, diphtheria and tetanus), animal venoms, infectious agents, or tumor cells.
 

Genetic Engineering

Dr. Prelog also reviewed genetic engineering techniques. In regenerative therapy or protein replacement therapy, skin fibroblasts or other cells are transfected with mRNA to enable conversion into induced pluripotent stem cells. This approach avoids the risk for DNA integration into the genome and associated mutation risks.

Another approach is making post-transcriptional modifications through RNA interference. For example, RNA structures can be used to inhibit the translation of disease-causing proteins. This technique is currently being tested against HIV and tumors such as melanoma.

In addition, mRNA technologies can be combined with CRISPR/Cas9 technology (“gene scissors”) to influence the creation of gene products even more precisely. The advantage of this technique is that mRNA is only transiently expressed, thus preventing unwanted side effects. Furthermore, mRNA is translated directly in the cytoplasm, leading to a faster initiation of gene editing.

Of the numerous ongoing clinical mRNA vaccine studies, around 70% focus on infections, about 12% on cancer, and the rest on autoimmune diseases and neurodegenerative disorders, said Dr. Prelog.
 

Research in Infections

Research in the fields of infectious diseases and oncology is the most advanced: mRNA vaccines against influenza and RSV are already in advanced clinical trials, Dr. Prelog told this news organization.

“Conventional influenza vaccines contain immunogenic surface molecules against hemagglutinin and neuraminidase in various combinations of influenza strains A and B and are produced in egg or cell cultures,” she said. “This is a time-consuming manufacturing process that takes months and, particularly with the egg-based process, bears the risk of changing the vaccine strain.”

“Additionally, influenza viruses undergo antigenic shift and drift through recombination, thus requiring annual adjustments to the vaccines. Thus, these influenza vaccines often lose accuracy in targeting circulating seasonal influenza strains.”

Several mRNA vaccines being tested contain not only coding sequences against hemagglutinin and neuraminidase but also for structural proteins of influenza viruses. “These are more conserved and mutate less easily, meaning they could serve as the basis for universal pandemic influenza vaccines,” said Dr. Prelog.

An advantage of mRNA vaccines, she added, is the strong cellular immune response that they elicit. This response is intended to provide additional protection alongside specific antibodies. An mRNA vaccine with coding sequences for the pre-fusion protein of RSV is in phase 3 trials for approval for vaccination in patients aged 60 years and older. It shows high effectiveness even in older patients and those with comorbidities.
 

Elaborate Purification Process

Bacterial origin plasmid DNA is used to produce mRNA vaccines. The mRNA vaccines for COVID-19 raised concerns that production-related DNA residues could pose a safety risk and cause autoimmune diseases.

These vaccines “typically undergo a very elaborate purification process,” said Dr. Prelog. “This involves enzymatic digestion with DNase to fragment and deplete plasmid DNA, followed by purification using chromatography columns, so that no safety-relevant DNA fragments should remain afterward.”

Thus, the Paul-Ehrlich-Institut also pointed out the very small, fragmented plasmid DNA residues of bacterial origin in mRNA COVID-19 vaccines pose no risk, unlike residual DNA from animal cell culture might pose in other vaccines.
 

Prevention and Therapy

In addition to the numerous advantages of mRNA vaccines (such as rapid adaptability to new or mutated pathogens, scalability, rapid production capability, self-adjuvant effect, strong induction of cellular immune responses, and safety), there are also challenges in RNA technology as a preventive and therapeutic measure, according to Dr. Prelog.

“Stability and storability, as well as the costs of new vaccine developments, play a role, as do the long-term effects regarding the persistence of antibody and cellular responses,” she said. The COVID-19 mRNA vaccines, for example, showed a well-maintained cellular immune response despite a tendency toward a rapid decline in humoral immune response.

“The experience with COVID-19 mRNA vaccines and the new vaccine developments based on mRNA technology give hope for an efficient and safe preventive and therapeutic use, particularly in the fields of infectious diseases and oncology,” Dr. Prelog concluded.

This story was translated from the Medscape German edition using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.

BERLIN — To date, mRNA vaccines have had their largest global presence in combating the COVID-19 pandemic. Intensive research is underway on many other potential applications for this vaccine technology, which suggests a promising future. Martina Prelog, MD, a pediatric and adolescent medicine specialist at the University Hospital of Würzburg in Germany, reported on the principles, research status, and perspectives for these vaccines at the 25th Travel and Health Forum of the Center for Travel Medicine in Berlin.

To understand the future, the immunologist first examined the past. “The induction of cellular and humoral immune responses by externally injected mRNA was discovered in the 1990s,” she said.
 

Instability Challenge

Significant hurdles in mRNA vaccinations included the instability of mRNA and the immune system’s ability to identify foreign mRNA as a threat and destroy mRNA fragments. “The breakthrough toward vaccination came through Dr. Katalin Karikó, who, along with Dr. Drew Weissman, both of the University of Pennsylvania School of Medicine, discovered in 2005 that modifications of mRNA (replacing the nucleoside uridine with pseudouridine) enable better stability of mRNA, reduced immunogenicity, and higher translational capacity at the ribosomes,” said Dr. Prelog.

With this discovery, the two researchers paved the way for the development of mRNA vaccines against COVID-19 and other diseases. They were awarded the Nobel Prize in medicine for their discovery last year.
 

Improved Scalability

“Since 2009, mRNA vaccines have been studied as a treatment option for cancer,” said Dr. Prelog. “Since 2012, they have been studied for the influenza virus and respiratory syncytial virus [RSV].” Consequently, several mRNA vaccines are currently in development or in approval studies. “The mRNA technology offers the advantage of quickly and flexibly responding to new variants of pathogens and the ability to scale up production when there is high demand for a particular vaccine.”

Different forms and designations of mRNA vaccines are used, depending on the application and desired effect, said Dr. Prelog.

In nucleoside-modified mRNA vaccines, modifications in the mRNA sequence enable the mRNA to remain in the body longer and to induce protein synthesis more effectively.

Lipid nanoparticle (LNP)–encapsulated mRNA vaccines protect the coding mRNA sequences against degradation by the body’s enzymes and facilitate the uptake of mRNA into cells, where it then triggers the production of the desired protein. In addition, LNPs are involved in cell stimulation and support the self-adjuvant effect of mRNA vaccines, thus eliminating the need for adjuvants.

Self-amplifying mRNA vaccines include a special mRNA that replicates itself in the cell and contains a sequence for RNA replicase, in addition to the coding sequence for the protein. This composition enables increased production of the target protein without the need for a high amount of external mRNA administration. Such vaccines could trigger a longer and stronger immune response because the immune system has more time to interact with the protein.
 

Cancer Immunotherapy

Dr. Prelog also discussed personalized vaccines for cancer immunotherapy. Personalized mRNA vaccines are tailored to the patient’s genetic characteristics and antigens. They could be used in cancer immunotherapy to activate the immune system selectively against tumor cells.

Multivalent mRNA vaccines contain mRNA that codes for multiple antigens rather than just one protein to generate an immune response. These vaccines could be particularly useful in fighting pathogens with variable or changing surface structures or in eliciting protection against multiple pathogens simultaneously.

The technology of mRNA-encoded antibodies involves introducing mRNA into the cell, which creates light and heavy chains of antibodies. This step leads to the formation of antibodies targeted against toxins (eg, diphtheria and tetanus), animal venoms, infectious agents, or tumor cells.
 

Genetic Engineering

Dr. Prelog also reviewed genetic engineering techniques. In regenerative therapy or protein replacement therapy, skin fibroblasts or other cells are transfected with mRNA to enable conversion into induced pluripotent stem cells. This approach avoids the risk for DNA integration into the genome and associated mutation risks.

Another approach is making post-transcriptional modifications through RNA interference. For example, RNA structures can be used to inhibit the translation of disease-causing proteins. This technique is currently being tested against HIV and tumors such as melanoma.

In addition, mRNA technologies can be combined with CRISPR/Cas9 technology (“gene scissors”) to influence the creation of gene products even more precisely. The advantage of this technique is that mRNA is only transiently expressed, thus preventing unwanted side effects. Furthermore, mRNA is translated directly in the cytoplasm, leading to a faster initiation of gene editing.

Of the numerous ongoing clinical mRNA vaccine studies, around 70% focus on infections, about 12% on cancer, and the rest on autoimmune diseases and neurodegenerative disorders, said Dr. Prelog.
 

Research in Infections

Research in the fields of infectious diseases and oncology is the most advanced: mRNA vaccines against influenza and RSV are already in advanced clinical trials, Dr. Prelog told this news organization.

“Conventional influenza vaccines contain immunogenic surface molecules against hemagglutinin and neuraminidase in various combinations of influenza strains A and B and are produced in egg or cell cultures,” she said. “This is a time-consuming manufacturing process that takes months and, particularly with the egg-based process, bears the risk of changing the vaccine strain.”

“Additionally, influenza viruses undergo antigenic shift and drift through recombination, thus requiring annual adjustments to the vaccines. Thus, these influenza vaccines often lose accuracy in targeting circulating seasonal influenza strains.”

Several mRNA vaccines being tested contain not only coding sequences against hemagglutinin and neuraminidase but also for structural proteins of influenza viruses. “These are more conserved and mutate less easily, meaning they could serve as the basis for universal pandemic influenza vaccines,” said Dr. Prelog.

An advantage of mRNA vaccines, she added, is the strong cellular immune response that they elicit. This response is intended to provide additional protection alongside specific antibodies. An mRNA vaccine with coding sequences for the pre-fusion protein of RSV is in phase 3 trials for approval for vaccination in patients aged 60 years and older. It shows high effectiveness even in older patients and those with comorbidities.
 

Elaborate Purification Process

Bacterial origin plasmid DNA is used to produce mRNA vaccines. The mRNA vaccines for COVID-19 raised concerns that production-related DNA residues could pose a safety risk and cause autoimmune diseases.

These vaccines “typically undergo a very elaborate purification process,” said Dr. Prelog. “This involves enzymatic digestion with DNase to fragment and deplete plasmid DNA, followed by purification using chromatography columns, so that no safety-relevant DNA fragments should remain afterward.”

Thus, the Paul-Ehrlich-Institut also pointed out the very small, fragmented plasmid DNA residues of bacterial origin in mRNA COVID-19 vaccines pose no risk, unlike residual DNA from animal cell culture might pose in other vaccines.
 

Prevention and Therapy

In addition to the numerous advantages of mRNA vaccines (such as rapid adaptability to new or mutated pathogens, scalability, rapid production capability, self-adjuvant effect, strong induction of cellular immune responses, and safety), there are also challenges in RNA technology as a preventive and therapeutic measure, according to Dr. Prelog.

“Stability and storability, as well as the costs of new vaccine developments, play a role, as do the long-term effects regarding the persistence of antibody and cellular responses,” she said. The COVID-19 mRNA vaccines, for example, showed a well-maintained cellular immune response despite a tendency toward a rapid decline in humoral immune response.

“The experience with COVID-19 mRNA vaccines and the new vaccine developments based on mRNA technology give hope for an efficient and safe preventive and therapeutic use, particularly in the fields of infectious diseases and oncology,” Dr. Prelog concluded.

This story was translated from the Medscape German edition using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.

BERLIN — To date, mRNA vaccines have had their largest global presence in combating the COVID-19 pandemic. Intensive research is underway on many other potential applications for this vaccine technology, which suggests a promising future. Martina Prelog, MD, a pediatric and adolescent medicine specialist at the University Hospital of Würzburg in Germany, reported on the principles, research status, and perspectives for these vaccines at the 25th Travel and Health Forum of the Center for Travel Medicine in Berlin.

To understand the future, the immunologist first examined the past. “The induction of cellular and humoral immune responses by externally injected mRNA was discovered in the 1990s,” she said.
 

Instability Challenge

Significant hurdles in mRNA vaccinations included the instability of mRNA and the immune system’s ability to identify foreign mRNA as a threat and destroy mRNA fragments. “The breakthrough toward vaccination came through Dr. Katalin Karikó, who, along with Dr. Drew Weissman, both of the University of Pennsylvania School of Medicine, discovered in 2005 that modifications of mRNA (replacing the nucleoside uridine with pseudouridine) enable better stability of mRNA, reduced immunogenicity, and higher translational capacity at the ribosomes,” said Dr. Prelog.

With this discovery, the two researchers paved the way for the development of mRNA vaccines against COVID-19 and other diseases. They were awarded the Nobel Prize in medicine for their discovery last year.
 

Improved Scalability

“Since 2009, mRNA vaccines have been studied as a treatment option for cancer,” said Dr. Prelog. “Since 2012, they have been studied for the influenza virus and respiratory syncytial virus [RSV].” Consequently, several mRNA vaccines are currently in development or in approval studies. “The mRNA technology offers the advantage of quickly and flexibly responding to new variants of pathogens and the ability to scale up production when there is high demand for a particular vaccine.”

Different forms and designations of mRNA vaccines are used, depending on the application and desired effect, said Dr. Prelog.

In nucleoside-modified mRNA vaccines, modifications in the mRNA sequence enable the mRNA to remain in the body longer and to induce protein synthesis more effectively.

Lipid nanoparticle (LNP)–encapsulated mRNA vaccines protect the coding mRNA sequences against degradation by the body’s enzymes and facilitate the uptake of mRNA into cells, where it then triggers the production of the desired protein. In addition, LNPs are involved in cell stimulation and support the self-adjuvant effect of mRNA vaccines, thus eliminating the need for adjuvants.

Self-amplifying mRNA vaccines include a special mRNA that replicates itself in the cell and contains a sequence for RNA replicase, in addition to the coding sequence for the protein. This composition enables increased production of the target protein without the need for a high amount of external mRNA administration. Such vaccines could trigger a longer and stronger immune response because the immune system has more time to interact with the protein.
 

Cancer Immunotherapy

Dr. Prelog also discussed personalized vaccines for cancer immunotherapy. Personalized mRNA vaccines are tailored to the patient’s genetic characteristics and antigens. They could be used in cancer immunotherapy to activate the immune system selectively against tumor cells.

Multivalent mRNA vaccines contain mRNA that codes for multiple antigens rather than just one protein to generate an immune response. These vaccines could be particularly useful in fighting pathogens with variable or changing surface structures or in eliciting protection against multiple pathogens simultaneously.

The technology of mRNA-encoded antibodies involves introducing mRNA into the cell, which creates light and heavy chains of antibodies. This step leads to the formation of antibodies targeted against toxins (eg, diphtheria and tetanus), animal venoms, infectious agents, or tumor cells.
 

Genetic Engineering

Dr. Prelog also reviewed genetic engineering techniques. In regenerative therapy or protein replacement therapy, skin fibroblasts or other cells are transfected with mRNA to enable conversion into induced pluripotent stem cells. This approach avoids the risk for DNA integration into the genome and associated mutation risks.

Another approach is making post-transcriptional modifications through RNA interference. For example, RNA structures can be used to inhibit the translation of disease-causing proteins. This technique is currently being tested against HIV and tumors such as melanoma.

In addition, mRNA technologies can be combined with CRISPR/Cas9 technology (“gene scissors”) to influence the creation of gene products even more precisely. The advantage of this technique is that mRNA is only transiently expressed, thus preventing unwanted side effects. Furthermore, mRNA is translated directly in the cytoplasm, leading to a faster initiation of gene editing.

Of the numerous ongoing clinical mRNA vaccine studies, around 70% focus on infections, about 12% on cancer, and the rest on autoimmune diseases and neurodegenerative disorders, said Dr. Prelog.
 

Research in Infections

Research in the fields of infectious diseases and oncology is the most advanced: mRNA vaccines against influenza and RSV are already in advanced clinical trials, Dr. Prelog told this news organization.

“Conventional influenza vaccines contain immunogenic surface molecules against hemagglutinin and neuraminidase in various combinations of influenza strains A and B and are produced in egg or cell cultures,” she said. “This is a time-consuming manufacturing process that takes months and, particularly with the egg-based process, bears the risk of changing the vaccine strain.”

“Additionally, influenza viruses undergo antigenic shift and drift through recombination, thus requiring annual adjustments to the vaccines. Thus, these influenza vaccines often lose accuracy in targeting circulating seasonal influenza strains.”

Several mRNA vaccines being tested contain not only coding sequences against hemagglutinin and neuraminidase but also for structural proteins of influenza viruses. “These are more conserved and mutate less easily, meaning they could serve as the basis for universal pandemic influenza vaccines,” said Dr. Prelog.

An advantage of mRNA vaccines, she added, is the strong cellular immune response that they elicit. This response is intended to provide additional protection alongside specific antibodies. An mRNA vaccine with coding sequences for the pre-fusion protein of RSV is in phase 3 trials for approval for vaccination in patients aged 60 years and older. It shows high effectiveness even in older patients and those with comorbidities.
 

Elaborate Purification Process

Bacterial origin plasmid DNA is used to produce mRNA vaccines. The mRNA vaccines for COVID-19 raised concerns that production-related DNA residues could pose a safety risk and cause autoimmune diseases.

These vaccines “typically undergo a very elaborate purification process,” said Dr. Prelog. “This involves enzymatic digestion with DNase to fragment and deplete plasmid DNA, followed by purification using chromatography columns, so that no safety-relevant DNA fragments should remain afterward.”

Thus, the Paul-Ehrlich-Institut also pointed out the very small, fragmented plasmid DNA residues of bacterial origin in mRNA COVID-19 vaccines pose no risk, unlike residual DNA from animal cell culture might pose in other vaccines.
 

Prevention and Therapy

In addition to the numerous advantages of mRNA vaccines (such as rapid adaptability to new or mutated pathogens, scalability, rapid production capability, self-adjuvant effect, strong induction of cellular immune responses, and safety), there are also challenges in RNA technology as a preventive and therapeutic measure, according to Dr. Prelog.

“Stability and storability, as well as the costs of new vaccine developments, play a role, as do the long-term effects regarding the persistence of antibody and cellular responses,” she said. The COVID-19 mRNA vaccines, for example, showed a well-maintained cellular immune response despite a tendency toward a rapid decline in humoral immune response.

“The experience with COVID-19 mRNA vaccines and the new vaccine developments based on mRNA technology give hope for an efficient and safe preventive and therapeutic use, particularly in the fields of infectious diseases and oncology,” Dr. Prelog concluded.

This story was translated from the Medscape German edition using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.

Cisplatin is a preferred treatment for a wide range of cancers, including breast, head and neck, lung, ovary, and more. However, its side effects — particularly nephrotoxicity — can be severe. Kidney injury on cisplatin is associated with higher mortality and can jeopardize a patient’s eligibility for other therapies.

Now, in a large study using data from six US cancer centers, researchers have developed a risk algorithm to predict acute kidney injury (AKI) after cisplatin administration.

A risk prediction calculator based on the algorithm is available online for patients and providers to determine an individual patient›s risk for kidney injury from cisplatin using readily available clinical data.

Other risk scores and risk prediction models have been developed to help clinicians assess in advance whether a patient might develop AKI after receiving cisplatin, so that more careful monitoring, dose adjustments, or an alternative treatment, if available, might be considered.

However, previous models were limited by factors such as small sample sizes, lack of external validation, older data, and liberal definitions of AKI, said Shruti Gupta, MD, MPH, director of onco-nephrology at Brigham and Women’s Hospital (BWH) and Dana-Farber Cancer Institute, and David E. Leaf, MD, MMSc, director of clinical and translational research in AKI, Division of Renal Medicine, BWH, Boston.

Dr. Gupta and Dr. Leaf believe their risk score for predicting severe AKI after intravenous (IV) cisplatin, published online in The BMJ, is “more accurate and generalizable than prior models for several reasons,” they told this news organization in a joint email.

“First, we externally validated our findings across cancer centers other than the one where it was developed,” they said. “Second, we focused on moderate to severe kidney injury, the most clinically relevant form of kidney damage, whereas prior models examined more mild forms of kidney injury. Third, we collected data on nearly 25,000 patients receiving their first dose of IV cisplatin, which is larger than all previous studies combined.”
 

‘Herculean Effort’

“We conceived of this study back in 2018, contacted collaborators at each participating cancer center, and had numerous meetings to try to gather granular data on patients treated with their first dose of intravenous (IV) cisplatin,” Dr. Gupta and Dr. Leaf explained. They also incorporated patient feedback from focus groups and surveys.

“This was truly a Herculean effort that involved physicians, programmers, research coordinators, and patients,” they said.

The multicenter study included 24,717 patients — 11,766 in the derivation cohort and 12,951 in the validation cohort. Overall, the median age was about 60 years, about 58% were men, and about 78% were White.

The primary outcome was cisplatin-induced AKI (CP-AKI), defined as a twofold or greater increase in serum creatinine or kidney replacement therapy within 14 days of a first dose of IV cisplatin.

The researchers found that the incidence of CP-AKI was 5.2% in the derivation cohort and 3.3% in the validation cohort. Their simple risk score consisting of nine covariates — age, hypertension, type 2 diabetes, hemoglobin level, white blood cell count, platelet count, serum albumin level, serum magnesium level, and cisplatin dose — predicted a higher risk for CP-AKI in both cohorts.

Notably, adding serum creatinine to the model did not change the area under the curve, and therefore, serum creatinine, though also an independent risk factor for CP-AKI, was not included in the score.

Patients in the highest risk category had 24-fold higher odds of CP-AKI in the derivation cohort and close to 18-fold higher odds in the validation cohort than those in the lowest risk category.

The primary model had a C statistic of 0.75 (95% CI, 0.73-0.76) and showed better discrimination for CP-AKI than previously published models, for which the C statistics ranged from 0.60 to 0.68. The first author of a paper on an earlier model, Shveta Motwani, MD, MMSc, of BWH and Dana-Farber Cancer Institute in Boston, is also a coauthor of the new study.

Greater severity of CP-AKI was associated with shorter 90-day survival (adjusted hazard ratio, 4.63; 95% CI, 3.56-6.02) for stage III CP-AKI vs no CP-AKI.
 

‘Definitive Work’

Joel M. Topf, MD, a nephrologist with expertise in chronic kidney disease in Detroit, who wasn’t involved in the development of the risk score, called the study “a definitive work on an important concept in oncology and nephrology.”

“While this is not the first attempt to devise a risk score, it is by far the biggest,” he told this news organization. Furthermore, the authors “used a diverse population, recruiting patients with a variety of cancers (previous attempts had often used a homogenous diagnosis, putting into question how generalizable the results were) from six different cancer centers.”

In addition, he said, “The authors did not restrict patients with chronic kidney disease or other significant comorbidities and used the geographic diversity to produce a cohort that has an age, gender, racial, and ethnic distribution, which is more representative of the US than previous, single-center attempts to risk score patients.”

An earlier model used the Kidney Disease: Improving Global Outcomes (KDIGO) consensus definition of AKI of an increase in serum creatinine of 0.3 mg/dL, he noted. “While a sensitive definition of AKI, it captures mild, hemodynamic increases in creatinine of questionable significance,” he said.

By contrast, the new score uses KDIGO stage II and above to define AKI. “This is a better choice, as we do not want to dissuade patients and doctors from choosing chemotherapy due to a fear of insignificant kidney damage,” he said.

All that said, Dr. Topf noted that neither the current score nor the earlier model included serum creatinine. “This is curious to me and may represent the small number of patients with representative elevated creatinine in the derivation cohort (only 1.3% with an estimated glomerular filtration rate [eGFR] < 45).”

“Since the cohort is made up of people who received cis-platinum, the low prevalence of eGFRs < 45 may be due to physicians steering away from cis-platinum in this group,” he suggested. “It would be unfortunate if this risk score gave an unintentional ‘green light’ to these patients, exposing them to predictable harm.”
 

‘Certainly Useful’

Anushree Shirali, MD, an associate professor in the Section of Nephrology and consulting physician, Yale Onco-Nephrology, Yale School of Medicine, in New Haven, Connecticut, said that having a prediction score for which patients are more likely to develop AKI after a single dose of cisplatin would be helpful for oncologists, as well as nephrologists.

As a nephrologist, Dr. Shirali mostly sees patients who already have AKI, she told this news organization. But there are circumstances in which the tool could still be helpful.

“Let’s say someone has abnormal kidney function at baseline — ie, creatinine is higher than the normal range — and they were on dialysis 5 years ago for something else, and now, they have cancer and may be given cisplatin. They worry about their chances of getting AKI and needing dialysis again,” she said. “That’s just one scenario in which I might be asked to answer that question and the tool would certainly be useful.”

Other scenarios could include someone who has just one kidney because they donated a kidney for transplant years ago, and now, they have a malignancy and wonder what their actual risk is of getting kidney issues on cisplatin.

Oncologists could use the tool to determine whether a patient should be treated with cisplatin, or if they’re at high risk, whether an alternative that’s not nephrotoxic might be used. By contrast, “if somebody’s low risk and an oncologist thinks cisplatin is the best agent they have, then they might want to go ahead and use it,” Dr. Shirali said.

Future research could take into consideration that CP-AKI is dose dependent, she suggested, because a prediction score that included the number of cisplatin doses could be even more helpful to determine risk. And, even though the derivation and validation cohorts for the new tool are representative of the US population, additional research should also include more racial/ethnic diversity, she said.

Dr. Gupta and Dr. Leaf hope their tool “will be utilized immediately by patients and providers to help predict an individual’s risk of cisplatin-associated kidney damage. It is easy to use, available for free online, and incorporates readily available clinical variables.”

If a patient is at high risk, the clinical team can consider preventive measures such as administering more IV fluids before receiving cisplatin or monitoring kidney function more closely afterward, they suggested.

Dr. Gupta reported research support from the National Institutes of Health (NIH) and the National Institute of Diabetes and Digestive and Kidney Diseases. She also reported research funding from BTG International, GE HealthCare, and AstraZeneca outside the submitted work. She is a member of GlaxoSmithKline’s Global Anemia Council, a consultant for Secretome and Proletariat Therapeutics, and founder and president emeritus of the American Society of Onconephrology (unpaid). Dr. Leaf is supported by NIH grants, reported research support from BioPorto, BTG International, and Metro International Biotech, and has served as a consultant. Dr. Topf reported an ownership stake in a few DaVita-run dialysis clinics. He also runs a vascular access center and has participated in advisory boards with Cara Therapeutics, Vifor, Astra Zeneca, Bayer, Renibus Therapeutics, Travere Therapeutics, and GlaxoSmithKline. He is president of NephJC, a nonprofit educational organization with no industry support. Dr. Shirali declared no competing interests.

A version of this article appeared on Medscape.com.

Cisplatin is a preferred treatment for a wide range of cancers, including breast, head and neck, lung, ovary, and more. However, its side effects — particularly nephrotoxicity — can be severe. Kidney injury on cisplatin is associated with higher mortality and can jeopardize a patient’s eligibility for other therapies.

Now, in a large study using data from six US cancer centers, researchers have developed a risk algorithm to predict acute kidney injury (AKI) after cisplatin administration.

A risk prediction calculator based on the algorithm is available online for patients and providers to determine an individual patient›s risk for kidney injury from cisplatin using readily available clinical data.

Other risk scores and risk prediction models have been developed to help clinicians assess in advance whether a patient might develop AKI after receiving cisplatin, so that more careful monitoring, dose adjustments, or an alternative treatment, if available, might be considered.

However, previous models were limited by factors such as small sample sizes, lack of external validation, older data, and liberal definitions of AKI, said Shruti Gupta, MD, MPH, director of onco-nephrology at Brigham and Women’s Hospital (BWH) and Dana-Farber Cancer Institute, and David E. Leaf, MD, MMSc, director of clinical and translational research in AKI, Division of Renal Medicine, BWH, Boston.

Dr. Gupta and Dr. Leaf believe their risk score for predicting severe AKI after intravenous (IV) cisplatin, published online in The BMJ, is “more accurate and generalizable than prior models for several reasons,” they told this news organization in a joint email.

“First, we externally validated our findings across cancer centers other than the one where it was developed,” they said. “Second, we focused on moderate to severe kidney injury, the most clinically relevant form of kidney damage, whereas prior models examined more mild forms of kidney injury. Third, we collected data on nearly 25,000 patients receiving their first dose of IV cisplatin, which is larger than all previous studies combined.”
 

‘Herculean Effort’

“We conceived of this study back in 2018, contacted collaborators at each participating cancer center, and had numerous meetings to try to gather granular data on patients treated with their first dose of intravenous (IV) cisplatin,” Dr. Gupta and Dr. Leaf explained. They also incorporated patient feedback from focus groups and surveys.

“This was truly a Herculean effort that involved physicians, programmers, research coordinators, and patients,” they said.

The multicenter study included 24,717 patients — 11,766 in the derivation cohort and 12,951 in the validation cohort. Overall, the median age was about 60 years, about 58% were men, and about 78% were White.

The primary outcome was cisplatin-induced AKI (CP-AKI), defined as a twofold or greater increase in serum creatinine or kidney replacement therapy within 14 days of a first dose of IV cisplatin.

The researchers found that the incidence of CP-AKI was 5.2% in the derivation cohort and 3.3% in the validation cohort. Their simple risk score consisting of nine covariates — age, hypertension, type 2 diabetes, hemoglobin level, white blood cell count, platelet count, serum albumin level, serum magnesium level, and cisplatin dose — predicted a higher risk for CP-AKI in both cohorts.

Notably, adding serum creatinine to the model did not change the area under the curve, and therefore, serum creatinine, though also an independent risk factor for CP-AKI, was not included in the score.

Patients in the highest risk category had 24-fold higher odds of CP-AKI in the derivation cohort and close to 18-fold higher odds in the validation cohort than those in the lowest risk category.

The primary model had a C statistic of 0.75 (95% CI, 0.73-0.76) and showed better discrimination for CP-AKI than previously published models, for which the C statistics ranged from 0.60 to 0.68. The first author of a paper on an earlier model, Shveta Motwani, MD, MMSc, of BWH and Dana-Farber Cancer Institute in Boston, is also a coauthor of the new study.

Greater severity of CP-AKI was associated with shorter 90-day survival (adjusted hazard ratio, 4.63; 95% CI, 3.56-6.02) for stage III CP-AKI vs no CP-AKI.
 

‘Definitive Work’

Joel M. Topf, MD, a nephrologist with expertise in chronic kidney disease in Detroit, who wasn’t involved in the development of the risk score, called the study “a definitive work on an important concept in oncology and nephrology.”

“While this is not the first attempt to devise a risk score, it is by far the biggest,” he told this news organization. Furthermore, the authors “used a diverse population, recruiting patients with a variety of cancers (previous attempts had often used a homogenous diagnosis, putting into question how generalizable the results were) from six different cancer centers.”

In addition, he said, “The authors did not restrict patients with chronic kidney disease or other significant comorbidities and used the geographic diversity to produce a cohort that has an age, gender, racial, and ethnic distribution, which is more representative of the US than previous, single-center attempts to risk score patients.”

An earlier model used the Kidney Disease: Improving Global Outcomes (KDIGO) consensus definition of AKI of an increase in serum creatinine of 0.3 mg/dL, he noted. “While a sensitive definition of AKI, it captures mild, hemodynamic increases in creatinine of questionable significance,” he said.

By contrast, the new score uses KDIGO stage II and above to define AKI. “This is a better choice, as we do not want to dissuade patients and doctors from choosing chemotherapy due to a fear of insignificant kidney damage,” he said.

All that said, Dr. Topf noted that neither the current score nor the earlier model included serum creatinine. “This is curious to me and may represent the small number of patients with representative elevated creatinine in the derivation cohort (only 1.3% with an estimated glomerular filtration rate [eGFR] < 45).”

“Since the cohort is made up of people who received cis-platinum, the low prevalence of eGFRs < 45 may be due to physicians steering away from cis-platinum in this group,” he suggested. “It would be unfortunate if this risk score gave an unintentional ‘green light’ to these patients, exposing them to predictable harm.”
 

‘Certainly Useful’

Anushree Shirali, MD, an associate professor in the Section of Nephrology and consulting physician, Yale Onco-Nephrology, Yale School of Medicine, in New Haven, Connecticut, said that having a prediction score for which patients are more likely to develop AKI after a single dose of cisplatin would be helpful for oncologists, as well as nephrologists.

As a nephrologist, Dr. Shirali mostly sees patients who already have AKI, she told this news organization. But there are circumstances in which the tool could still be helpful.

“Let’s say someone has abnormal kidney function at baseline — ie, creatinine is higher than the normal range — and they were on dialysis 5 years ago for something else, and now, they have cancer and may be given cisplatin. They worry about their chances of getting AKI and needing dialysis again,” she said. “That’s just one scenario in which I might be asked to answer that question and the tool would certainly be useful.”

Other scenarios could include someone who has just one kidney because they donated a kidney for transplant years ago, and now, they have a malignancy and wonder what their actual risk is of getting kidney issues on cisplatin.

Oncologists could use the tool to determine whether a patient should be treated with cisplatin, or if they’re at high risk, whether an alternative that’s not nephrotoxic might be used. By contrast, “if somebody’s low risk and an oncologist thinks cisplatin is the best agent they have, then they might want to go ahead and use it,” Dr. Shirali said.

Future research could take into consideration that CP-AKI is dose dependent, she suggested, because a prediction score that included the number of cisplatin doses could be even more helpful to determine risk. And, even though the derivation and validation cohorts for the new tool are representative of the US population, additional research should also include more racial/ethnic diversity, she said.

Dr. Gupta and Dr. Leaf hope their tool “will be utilized immediately by patients and providers to help predict an individual’s risk of cisplatin-associated kidney damage. It is easy to use, available for free online, and incorporates readily available clinical variables.”

If a patient is at high risk, the clinical team can consider preventive measures such as administering more IV fluids before receiving cisplatin or monitoring kidney function more closely afterward, they suggested.

Dr. Gupta reported research support from the National Institutes of Health (NIH) and the National Institute of Diabetes and Digestive and Kidney Diseases. She also reported research funding from BTG International, GE HealthCare, and AstraZeneca outside the submitted work. She is a member of GlaxoSmithKline’s Global Anemia Council, a consultant for Secretome and Proletariat Therapeutics, and founder and president emeritus of the American Society of Onconephrology (unpaid). Dr. Leaf is supported by NIH grants, reported research support from BioPorto, BTG International, and Metro International Biotech, and has served as a consultant. Dr. Topf reported an ownership stake in a few DaVita-run dialysis clinics. He also runs a vascular access center and has participated in advisory boards with Cara Therapeutics, Vifor, Astra Zeneca, Bayer, Renibus Therapeutics, Travere Therapeutics, and GlaxoSmithKline. He is president of NephJC, a nonprofit educational organization with no industry support. Dr. Shirali declared no competing interests.

A version of this article appeared on Medscape.com.

Cisplatin is a preferred treatment for a wide range of cancers, including breast, head and neck, lung, ovary, and more. However, its side effects — particularly nephrotoxicity — can be severe. Kidney injury on cisplatin is associated with higher mortality and can jeopardize a patient’s eligibility for other therapies.

Now, in a large study using data from six US cancer centers, researchers have developed a risk algorithm to predict acute kidney injury (AKI) after cisplatin administration.

A risk prediction calculator based on the algorithm is available online for patients and providers to determine an individual patient›s risk for kidney injury from cisplatin using readily available clinical data.

Other risk scores and risk prediction models have been developed to help clinicians assess in advance whether a patient might develop AKI after receiving cisplatin, so that more careful monitoring, dose adjustments, or an alternative treatment, if available, might be considered.

However, previous models were limited by factors such as small sample sizes, lack of external validation, older data, and liberal definitions of AKI, said Shruti Gupta, MD, MPH, director of onco-nephrology at Brigham and Women’s Hospital (BWH) and Dana-Farber Cancer Institute, and David E. Leaf, MD, MMSc, director of clinical and translational research in AKI, Division of Renal Medicine, BWH, Boston.

Dr. Gupta and Dr. Leaf believe their risk score for predicting severe AKI after intravenous (IV) cisplatin, published online in The BMJ, is “more accurate and generalizable than prior models for several reasons,” they told this news organization in a joint email.

“First, we externally validated our findings across cancer centers other than the one where it was developed,” they said. “Second, we focused on moderate to severe kidney injury, the most clinically relevant form of kidney damage, whereas prior models examined more mild forms of kidney injury. Third, we collected data on nearly 25,000 patients receiving their first dose of IV cisplatin, which is larger than all previous studies combined.”
 

‘Herculean Effort’

“We conceived of this study back in 2018, contacted collaborators at each participating cancer center, and had numerous meetings to try to gather granular data on patients treated with their first dose of intravenous (IV) cisplatin,” Dr. Gupta and Dr. Leaf explained. They also incorporated patient feedback from focus groups and surveys.

“This was truly a Herculean effort that involved physicians, programmers, research coordinators, and patients,” they said.

The multicenter study included 24,717 patients — 11,766 in the derivation cohort and 12,951 in the validation cohort. Overall, the median age was about 60 years, about 58% were men, and about 78% were White.

The primary outcome was cisplatin-induced AKI (CP-AKI), defined as a twofold or greater increase in serum creatinine or kidney replacement therapy within 14 days of a first dose of IV cisplatin.

The researchers found that the incidence of CP-AKI was 5.2% in the derivation cohort and 3.3% in the validation cohort. Their simple risk score consisting of nine covariates — age, hypertension, type 2 diabetes, hemoglobin level, white blood cell count, platelet count, serum albumin level, serum magnesium level, and cisplatin dose — predicted a higher risk for CP-AKI in both cohorts.

Notably, adding serum creatinine to the model did not change the area under the curve, and therefore, serum creatinine, though also an independent risk factor for CP-AKI, was not included in the score.

Patients in the highest risk category had 24-fold higher odds of CP-AKI in the derivation cohort and close to 18-fold higher odds in the validation cohort than those in the lowest risk category.

The primary model had a C statistic of 0.75 (95% CI, 0.73-0.76) and showed better discrimination for CP-AKI than previously published models, for which the C statistics ranged from 0.60 to 0.68. The first author of a paper on an earlier model, Shveta Motwani, MD, MMSc, of BWH and Dana-Farber Cancer Institute in Boston, is also a coauthor of the new study.

Greater severity of CP-AKI was associated with shorter 90-day survival (adjusted hazard ratio, 4.63; 95% CI, 3.56-6.02) for stage III CP-AKI vs no CP-AKI.
 

‘Definitive Work’

Joel M. Topf, MD, a nephrologist with expertise in chronic kidney disease in Detroit, who wasn’t involved in the development of the risk score, called the study “a definitive work on an important concept in oncology and nephrology.”

“While this is not the first attempt to devise a risk score, it is by far the biggest,” he told this news organization. Furthermore, the authors “used a diverse population, recruiting patients with a variety of cancers (previous attempts had often used a homogenous diagnosis, putting into question how generalizable the results were) from six different cancer centers.”

In addition, he said, “The authors did not restrict patients with chronic kidney disease or other significant comorbidities and used the geographic diversity to produce a cohort that has an age, gender, racial, and ethnic distribution, which is more representative of the US than previous, single-center attempts to risk score patients.”

An earlier model used the Kidney Disease: Improving Global Outcomes (KDIGO) consensus definition of AKI of an increase in serum creatinine of 0.3 mg/dL, he noted. “While a sensitive definition of AKI, it captures mild, hemodynamic increases in creatinine of questionable significance,” he said.

By contrast, the new score uses KDIGO stage II and above to define AKI. “This is a better choice, as we do not want to dissuade patients and doctors from choosing chemotherapy due to a fear of insignificant kidney damage,” he said.

All that said, Dr. Topf noted that neither the current score nor the earlier model included serum creatinine. “This is curious to me and may represent the small number of patients with representative elevated creatinine in the derivation cohort (only 1.3% with an estimated glomerular filtration rate [eGFR] < 45).”

“Since the cohort is made up of people who received cis-platinum, the low prevalence of eGFRs < 45 may be due to physicians steering away from cis-platinum in this group,” he suggested. “It would be unfortunate if this risk score gave an unintentional ‘green light’ to these patients, exposing them to predictable harm.”
 

‘Certainly Useful’

Anushree Shirali, MD, an associate professor in the Section of Nephrology and consulting physician, Yale Onco-Nephrology, Yale School of Medicine, in New Haven, Connecticut, said that having a prediction score for which patients are more likely to develop AKI after a single dose of cisplatin would be helpful for oncologists, as well as nephrologists.

As a nephrologist, Dr. Shirali mostly sees patients who already have AKI, she told this news organization. But there are circumstances in which the tool could still be helpful.

“Let’s say someone has abnormal kidney function at baseline — ie, creatinine is higher than the normal range — and they were on dialysis 5 years ago for something else, and now, they have cancer and may be given cisplatin. They worry about their chances of getting AKI and needing dialysis again,” she said. “That’s just one scenario in which I might be asked to answer that question and the tool would certainly be useful.”

Other scenarios could include someone who has just one kidney because they donated a kidney for transplant years ago, and now, they have a malignancy and wonder what their actual risk is of getting kidney issues on cisplatin.

Oncologists could use the tool to determine whether a patient should be treated with cisplatin, or if they’re at high risk, whether an alternative that’s not nephrotoxic might be used. By contrast, “if somebody’s low risk and an oncologist thinks cisplatin is the best agent they have, then they might want to go ahead and use it,” Dr. Shirali said.

Future research could take into consideration that CP-AKI is dose dependent, she suggested, because a prediction score that included the number of cisplatin doses could be even more helpful to determine risk. And, even though the derivation and validation cohorts for the new tool are representative of the US population, additional research should also include more racial/ethnic diversity, she said.

Dr. Gupta and Dr. Leaf hope their tool “will be utilized immediately by patients and providers to help predict an individual’s risk of cisplatin-associated kidney damage. It is easy to use, available for free online, and incorporates readily available clinical variables.”

If a patient is at high risk, the clinical team can consider preventive measures such as administering more IV fluids before receiving cisplatin or monitoring kidney function more closely afterward, they suggested.

Dr. Gupta reported research support from the National Institutes of Health (NIH) and the National Institute of Diabetes and Digestive and Kidney Diseases. She also reported research funding from BTG International, GE HealthCare, and AstraZeneca outside the submitted work. She is a member of GlaxoSmithKline’s Global Anemia Council, a consultant for Secretome and Proletariat Therapeutics, and founder and president emeritus of the American Society of Onconephrology (unpaid). Dr. Leaf is supported by NIH grants, reported research support from BioPorto, BTG International, and Metro International Biotech, and has served as a consultant. Dr. Topf reported an ownership stake in a few DaVita-run dialysis clinics. He also runs a vascular access center and has participated in advisory boards with Cara Therapeutics, Vifor, Astra Zeneca, Bayer, Renibus Therapeutics, Travere Therapeutics, and GlaxoSmithKline. He is president of NephJC, a nonprofit educational organization with no industry support. Dr. Shirali declared no competing interests.

A version of this article appeared on Medscape.com.

This discussion was recorded on March 29, 2024. The transcript has been edited for clarity.

Robert D. Glatter, MD: Joining me today to discuss the use of methoxyflurane (Penthrox), an inhaled nonopioid analgesic for the relief of acute pain, is Dr. William Kenneth (Ken) Milne, an emergency physician at Strathroy Middlesex General Hospital in Ontario, Canada, and the founder of the well-known podcast The Skeptics’ Guide to Emergency Medicine (SGEM).

Also joining me is Dr. Sergey Motov, an emergency physician and research director at Maimonides Medical Center in Brooklyn, New York, and an expert in pain management. I want to welcome both of you and thank you for joining me.
 

RAMPED Trial: Evaluating the Efficacy of Methoxyflurane

Dr. Glatter: Ken, your recent post on Twitter [now X] regarding the utility of Penthrox in the RAMPED trial really caught my attention. While the trial was from 2021, it really is relevant regarding the prehospital management of pain in the practice of emergency medicine, and certainly in-hospital practice. I was hoping you could review the study design but also get into the rationale behind the use of this novel agent.

William Kenneth (Ken) Milne, MD, MSc: Sure. I’d be happy to kick this episode off with talking about a study that was published in 2020 in Academic Emergency Medicine. It was an Australian study by Brichko et al., and they were doing a randomized controlled trial looking at methoxyflurane vs standard care.

They selected out a population of adults, which they defined as 18-75 years of age. They were in the prehospital setting and they had a pain score of greater than 8. They gave the participants methoxyflurane, which is also called the “green whistle.” They had the subjects take that for their prehospital pain, and they compared that with whatever your standard analgesic in the prehospital setting would be.

Their primary outcome was how many patients had at least 50% reduction in their pain score within 30 minutes. They recruited about 120 people, and they found that there was no statistical difference in the primary outcome between methoxyflurane and standard care. Again, that primary outcome was a reduction in pain score by greater than 50% at 30 minutes, and there wasn’t a statistical difference between the two.

There are obviously limits to any study, and it was a convenience sample. This was an unmasked trial, so people knew if they were getting this green whistle, which is popular in Australia. People would be familiar with this device, and they didn’t compare it with a sham or placebo group.

Pharmacology of Penthrox: Its Role and Mechanism of Action

Dr. Glatter: The primary outcome wasn’t met, but certainly secondary outcomes were. There was, again, a relatively small number of patients in this trial. That said, there was significant pain relief. I think there are issues with the trial, as with any trial limitations.

Getting to the pharmacology of Penthrox, can you describe this inhaled anesthetic and how we use it, specifically its role at the subanesthetic doses?

Sergey M. Motov, MD: Methoxyflurane is embedded in the green whistle package, and that whole contraption is called Penthrox. It’s an inhaled volatile fluorinated hydrocarbon anesthetic that was predominantly used, I’d say 40, 50 years ago, for general anesthesia and slowly but surely fell out of favor due to the fact that, when used for prolonged duration or in supratherapeutic doses, there were cases of severe or even fatal nephrotoxicity and hepatotoxicity.

In the late ‘70s and early ‘80s, all the fluranes came on board that are slightly different as general anesthetics, and methoxyflurane started slowly falling out of favor. Because of this paucity and then a subsequent slightly greater number of cases of nephrotoxicity and hepatotoxicity, [the US Food and Drug Administration] FDA made a decision to pull the drug off the market in 2005. FDA successfully accomplished its mission and since then has pretty much banned the use of inhaled methoxyflurane in any shape, form, or color in the United States.

Going back to the green whistle, it has been used in Australia probably for about 50-60 years, and has been used in Europe for probably 10-20 years. Ken can attest that it has been used in Canada for at least a decade and the track record is phenomenal.

We are using subanesthetic, even supratherapeutic doses that, based on available literature, has no incidence of this fatal hepatotoxicity or nephrotoxicity. We’re talking about 10 million doses administered worldwide, except in the United States. There are 40-plus randomized clinical trials with over 30,000 patients enrolled that prove efficacy and safety.

That’s where we are right now, in a conundrum. We have a great deal of data all over the world, except in the United States, that push for the use of this noninvasive, patient-controlled nonopioid inhaled anesthetic. We just don’t have the access in North America, with the exception of Canada.

Regulatory Hurdles: Challenges in FDA Approval

Dr. Glatter: Absolutely. The FDA wants to be cautious, but if you look at the evidence base of data on this, it really indicates otherwise. Do you think that these roadblocks can be somehow overcome?

Dr. Milne: In the 2000s and 2010s, everybody was focused on opioids and all the dangers and potential adverse events. Opioids are great drugs like many other drugs; it depends on dose and duration. If used properly, it’s an excellent drug. Well, here’s another excellent drug if it’s used properly, and the adverse events are dependent on their dose and duration. Penthrox, or methoxyflurane, is a subtherapeutic, small dose and there have been no reported cases of addiction or abuse related to these inhalers.

Dr. Glatter: That argues for the point — and I’ll turn this over to you, Sergey — of how can this not, in my mind, be an issue that the FDA can overcome.

Dr. Motov: I agree with you. It’s very hard for me to speak on behalf of the FDA, to allude to their thinking processes, but we need to be up to speed with the evidence. The first thing is, why don’t you study the drug in the United States? I’m not asking you to lift the ban, which you put in 2005, but why don’t you honor what has been done over two decades and at least open the door a little bit and let us do what we do best? Why don’t you allow us to do the research in a controlled setting with a carefully, properly selected group of patients without underlying renal or hepatic insufficiency and see where we’re at?

Let’s compare it against placebo. If that’s not ethical, let’s compare it against active comparators — God knows we have 15-20 drugs we can use — and let’s see where we’re at. Ken has been nothing short of superb when it comes to evidence. Let us put the evidence together.

Dr. Milne: If there were concerns decades ago, those need to be addressed. As science is iterative and as other information becomes available, the scientific method would say, Let’s reexamine this and let’s reexamine our position, and do that with evidence. To do that, it has to have validity within the US system. Someone like you doing the research, you are a pain research guru; you should be doing this research to say, “Does it work or not? Does this nonapproval still stand today in 2024?”

Dr. Motov: Thank you for the shout-out, and I agree with you. All of us, those who are interested, on the frontiers of emergency care — as present clinicians — we should be doing this. There is nothing that will convince the FDA more than properly and rightly conducted research, time to reassess the evidence, and time to be less rigid. I understand that you placed a ban 20 years ago, but let’s go with the science. We cannot be behind it.

Exploring the Ecological Footprint of Methoxyflurane

Dr. Milne: There was an Austrian study in 2022 and a very interesting study out of the UK looking at life-cycle impact assessment on the environment. If we’re not just concerned about patient care —obviously, we want to provide patients with a safe and effective product, compared with other products that are available that might not have as good a safety profile — this looks at the impact on the environment.

Dr. Glatter: Ken, can you tell me about some of your recent research regarding the environmental effects related to use of Penthrox, but also its utility pharmacologically and its mechanism of action?

Dr. Milne: There was a really interesting study published this year by Martindale in the Emergency Medicine Journal. It took a different approach to this question about could we be using this drug, and why should we be using this drug? Sergey and I have already talked about the potential benefits and the potential harms. I mentioned opioids and some of the concerns about that. For this drug, if we’re using it in the prehospital setting in this little green whistle, the potential benefits look really good, and we haven’t seen any of the potential harms come through in the literature.

This was another line of evidence of why this might be a good drug, because of the environmental impact of this low-dose methoxyflurane. They compared it with nitrous oxide and said, “Well, what about the life-cycle impact on the environment of using this and the overall cradle-to-grave environmental impacts?”

Obviously, Sergey and I are interested in patient care, and we treat patients one at a time. But we have a larger responsibility to social determinants of health, like our environment. If you look at the overall cradle-to-grave environmental impact of this drug, it was better than for nitrous oxide when looking specifically at climate-change impact. That might be another reason, another line of argument, that could be put forward in the United States to say, “We want to have a healthy environment and a healthy option for patients.”

I’ll let Sergey speak to mechanisms of action and those types of things.

Dr. Motov: As a general anesthetic and hydrocarbonated volatile ones, I’m just going to say that it causes this generalized diffuse cortical depression, and there are no particular channels, receptors, or enzymes we need to worry much about. In short, it’s an inhaled gas used to put patients or people to sleep.

Over the past 30 or 40 years — and I’ll go back to the past decade — there have been numerous studies in different countries (outside of the United States, of course), and with the recent study that Ken just cited, there were comparisons for managing predominantly acute traumatic injuries in pediatric and adult populations presenting to EDs in various regions of the world that compared Penthrox, or the green whistle, with either placebo or active comparators, which included parenteral opioids, oral opioids, and NSAIDs.

The recent systematic review by Fabbri, out of Italy, showed that for ultra–short-term pain — we’re talking about 5, 10, or 15 minutes — inhaled methoxyflurane was found to be equal or even superior to standard of care, primarily related to parenteral opioids, and safety was off the hook. Interestingly, with respect to analgesia, they found that geriatric patients seemed to be responding more, with respect to changing pain score, than younger adults — we’re talking about ages 18-64 vs 65 or older. Again, we need to make sure that we carefully select those elderly people without underlying renal or hepatic insufficiency.

To wrap this up, there is evidence clearly supporting its analgesic efficacy and safety, even in comparison to commonly used and traditionally accepted analgesic modalities that we use for managing acute pain.

US Military Use and Implications for Civilian Practice

Dr. Glatter: Do you think that methoxyflurane’s use in the military will help propel its use in clinical settings in the US, and possibly convince the FDA to look at this closer? The military is currently using it in deployed combat veterans in an ongoing fashion.

Dr. Motov: I’m excited that the Department of Defense in the United States has taken the lead, and they’re being very progressive. There are data that we’ve adapted to the civilian environment by use of intranasal opioids and intranasal ketamine with more doctors who came out of the military. In the military, it’s a kingdom within a kingdom. I don’t know their relationship with the FDA, but I support the military’s pharmacologic initiative by honoring and disseminating their research once it becomes available.

For us nonmilitary folks, we still need to work with the FDA. We need to convince the FDA to let us study the drug, and then we need to pile the evidence within the United States so that the FDA will start looking at this favorably. It wouldn’t hurt and it wouldn’t harm. Any piece of evidence will add to the existing body of literature that we need to allow this medication to be available to us.

Safety Considerations and Aerosolization Concerns

Dr. Glatter: Its safety in children is well established in Australia and throughout the world. I think it deserves a careful look, and the evidence that you’ve both presented argues for the use of this prehospital but also in hospital. I guess there was concern in the hospital with underventilation and healthcare workers being exposed to the fumes, and then getting headaches, dizziness, and so forth. I don’t know if that’s borne out, Ken, in any of your experience in Canada at all.

Dr. Milne: We currently don’t have it in our shop. It’s being used in British Columbia right now in the prehospital setting, and I’m not aware of anybody using it in their department. It’s used prehospital as far as I know.

Dr. Motov: I can attest to it, if I may, because I had familiarized myself with the device. I actually was able to hold it in my hands. I have not used it yet but I had the prototype. The way it’s set up, there is an activated charcoal chamber that sits right on top of the device, which serves as the scavenger for exhaled air that contains particles of methoxyflurane. In theory, but I’m telling how it is in practicality, it significantly reduces occupational exposure, based on data that lacks specifics.

Although most of the researchers did not measure the concentration of methoxyflurane in ambient air within the treatment room in the EDs, I believe the additional data sources clearly stating that it’s within or even below the detectable level that would cause any harm. Once again, we need to honor pathology. We need to make sure that pregnant women will not be exposed to it.

Dr. Milne: In 2024, we also need to be concerned about aerosolizing procedures and aerosolizing treatments, and just take that into account because we should be considering all the potential benefits and all the potential harms. Going through the COVID-19 pandemic, there was concern about transmission and whether or not it was droplet or aerosolized.

There was an observational study published in 2022 in Austria by Trimmel in BMC Emergency Medicine showing similar results. It seemed to work well and potential harms didn’t get picked up. They had to stop the study early because of COVID-19.

We need to always focus in on the potential benefits, the potential harms; where does the science land? Where do the data lie? Then we move forward from that and make informed decisions.

Final Thoughts

Dr. Glatter: Are there any key takeaways you’d like to share with our audience?

Dr. Milne: One of the takeaways from this whole conversation is that science is iterative and science changes. When new evidence becomes available, and we’ve seen it accumulate around the world, we as scientists, as a researcher, as somebody committed to great patient care should revisit our positions on this. Since there is a prohibition against this medication, I think it’s time to reassess that stance and move forward to see if it still is accurate today.

Dr. Motov: I wholeheartedly agree with this. Thank you, Ken, for bringing this up. Good point.

Dr. Glatter: This has been a really informative discussion. I think our audience will certainly embrace this. Thank you very much for your time; it’s much appreciated.
 

Dr. Glatter is an assistant professor of emergency medicine at Zucker School of Medicine at Hofstra/Northwell in Hempstead, New York. He is a medical adviser for Medscape and hosts the Hot Topics in EM series. Dr. Milne is an emergency physician at Strathroy Middlesex General Hospital in Ontario, Canada, and the founder of the well-known podcast The Skeptics’ Guide to Emergency Medicine (SGEM). Dr. Motov is professor of emergency medicine and director of research in the Department of Emergency Medicine at Maimonides Medical Center in Brooklyn, New York. He is passionate about safe and effective pain management in the emergency department, and has numerous publications on the subject of opioid alternatives in pain management. Dr. Glatter, Dr. Milne, and Dr. Motov had no conflicts of interest to disclose.

A version of this article appeared on Medscape.com.

This discussion was recorded on March 29, 2024. The transcript has been edited for clarity.

Robert D. Glatter, MD: Joining me today to discuss the use of methoxyflurane (Penthrox), an inhaled nonopioid analgesic for the relief of acute pain, is Dr. William Kenneth (Ken) Milne, an emergency physician at Strathroy Middlesex General Hospital in Ontario, Canada, and the founder of the well-known podcast The Skeptics’ Guide to Emergency Medicine (SGEM).

Also joining me is Dr. Sergey Motov, an emergency physician and research director at Maimonides Medical Center in Brooklyn, New York, and an expert in pain management. I want to welcome both of you and thank you for joining me.
 

RAMPED Trial: Evaluating the Efficacy of Methoxyflurane

Dr. Glatter: Ken, your recent post on Twitter [now X] regarding the utility of Penthrox in the RAMPED trial really caught my attention. While the trial was from 2021, it really is relevant regarding the prehospital management of pain in the practice of emergency medicine, and certainly in-hospital practice. I was hoping you could review the study design but also get into the rationale behind the use of this novel agent.

William Kenneth (Ken) Milne, MD, MSc: Sure. I’d be happy to kick this episode off with talking about a study that was published in 2020 in Academic Emergency Medicine. It was an Australian study by Brichko et al., and they were doing a randomized controlled trial looking at methoxyflurane vs standard care.

They selected out a population of adults, which they defined as 18-75 years of age. They were in the prehospital setting and they had a pain score of greater than 8. They gave the participants methoxyflurane, which is also called the “green whistle.” They had the subjects take that for their prehospital pain, and they compared that with whatever your standard analgesic in the prehospital setting would be.

Their primary outcome was how many patients had at least 50% reduction in their pain score within 30 minutes. They recruited about 120 people, and they found that there was no statistical difference in the primary outcome between methoxyflurane and standard care. Again, that primary outcome was a reduction in pain score by greater than 50% at 30 minutes, and there wasn’t a statistical difference between the two.

There are obviously limits to any study, and it was a convenience sample. This was an unmasked trial, so people knew if they were getting this green whistle, which is popular in Australia. People would be familiar with this device, and they didn’t compare it with a sham or placebo group.

Pharmacology of Penthrox: Its Role and Mechanism of Action

Dr. Glatter: The primary outcome wasn’t met, but certainly secondary outcomes were. There was, again, a relatively small number of patients in this trial. That said, there was significant pain relief. I think there are issues with the trial, as with any trial limitations.

Getting to the pharmacology of Penthrox, can you describe this inhaled anesthetic and how we use it, specifically its role at the subanesthetic doses?

Sergey M. Motov, MD: Methoxyflurane is embedded in the green whistle package, and that whole contraption is called Penthrox. It’s an inhaled volatile fluorinated hydrocarbon anesthetic that was predominantly used, I’d say 40, 50 years ago, for general anesthesia and slowly but surely fell out of favor due to the fact that, when used for prolonged duration or in supratherapeutic doses, there were cases of severe or even fatal nephrotoxicity and hepatotoxicity.

In the late ‘70s and early ‘80s, all the fluranes came on board that are slightly different as general anesthetics, and methoxyflurane started slowly falling out of favor. Because of this paucity and then a subsequent slightly greater number of cases of nephrotoxicity and hepatotoxicity, [the US Food and Drug Administration] FDA made a decision to pull the drug off the market in 2005. FDA successfully accomplished its mission and since then has pretty much banned the use of inhaled methoxyflurane in any shape, form, or color in the United States.

Going back to the green whistle, it has been used in Australia probably for about 50-60 years, and has been used in Europe for probably 10-20 years. Ken can attest that it has been used in Canada for at least a decade and the track record is phenomenal.

We are using subanesthetic, even supratherapeutic doses that, based on available literature, has no incidence of this fatal hepatotoxicity or nephrotoxicity. We’re talking about 10 million doses administered worldwide, except in the United States. There are 40-plus randomized clinical trials with over 30,000 patients enrolled that prove efficacy and safety.

That’s where we are right now, in a conundrum. We have a great deal of data all over the world, except in the United States, that push for the use of this noninvasive, patient-controlled nonopioid inhaled anesthetic. We just don’t have the access in North America, with the exception of Canada.

Regulatory Hurdles: Challenges in FDA Approval

Dr. Glatter: Absolutely. The FDA wants to be cautious, but if you look at the evidence base of data on this, it really indicates otherwise. Do you think that these roadblocks can be somehow overcome?

Dr. Milne: In the 2000s and 2010s, everybody was focused on opioids and all the dangers and potential adverse events. Opioids are great drugs like many other drugs; it depends on dose and duration. If used properly, it’s an excellent drug. Well, here’s another excellent drug if it’s used properly, and the adverse events are dependent on their dose and duration. Penthrox, or methoxyflurane, is a subtherapeutic, small dose and there have been no reported cases of addiction or abuse related to these inhalers.

Dr. Glatter: That argues for the point — and I’ll turn this over to you, Sergey — of how can this not, in my mind, be an issue that the FDA can overcome.

Dr. Motov: I agree with you. It’s very hard for me to speak on behalf of the FDA, to allude to their thinking processes, but we need to be up to speed with the evidence. The first thing is, why don’t you study the drug in the United States? I’m not asking you to lift the ban, which you put in 2005, but why don’t you honor what has been done over two decades and at least open the door a little bit and let us do what we do best? Why don’t you allow us to do the research in a controlled setting with a carefully, properly selected group of patients without underlying renal or hepatic insufficiency and see where we’re at?

Let’s compare it against placebo. If that’s not ethical, let’s compare it against active comparators — God knows we have 15-20 drugs we can use — and let’s see where we’re at. Ken has been nothing short of superb when it comes to evidence. Let us put the evidence together.

Dr. Milne: If there were concerns decades ago, those need to be addressed. As science is iterative and as other information becomes available, the scientific method would say, Let’s reexamine this and let’s reexamine our position, and do that with evidence. To do that, it has to have validity within the US system. Someone like you doing the research, you are a pain research guru; you should be doing this research to say, “Does it work or not? Does this nonapproval still stand today in 2024?”

Dr. Motov: Thank you for the shout-out, and I agree with you. All of us, those who are interested, on the frontiers of emergency care — as present clinicians — we should be doing this. There is nothing that will convince the FDA more than properly and rightly conducted research, time to reassess the evidence, and time to be less rigid. I understand that you placed a ban 20 years ago, but let’s go with the science. We cannot be behind it.

Exploring the Ecological Footprint of Methoxyflurane

Dr. Milne: There was an Austrian study in 2022 and a very interesting study out of the UK looking at life-cycle impact assessment on the environment. If we’re not just concerned about patient care —obviously, we want to provide patients with a safe and effective product, compared with other products that are available that might not have as good a safety profile — this looks at the impact on the environment.

Dr. Glatter: Ken, can you tell me about some of your recent research regarding the environmental effects related to use of Penthrox, but also its utility pharmacologically and its mechanism of action?

Dr. Milne: There was a really interesting study published this year by Martindale in the Emergency Medicine Journal. It took a different approach to this question about could we be using this drug, and why should we be using this drug? Sergey and I have already talked about the potential benefits and the potential harms. I mentioned opioids and some of the concerns about that. For this drug, if we’re using it in the prehospital setting in this little green whistle, the potential benefits look really good, and we haven’t seen any of the potential harms come through in the literature.

This was another line of evidence of why this might be a good drug, because of the environmental impact of this low-dose methoxyflurane. They compared it with nitrous oxide and said, “Well, what about the life-cycle impact on the environment of using this and the overall cradle-to-grave environmental impacts?”

Obviously, Sergey and I are interested in patient care, and we treat patients one at a time. But we have a larger responsibility to social determinants of health, like our environment. If you look at the overall cradle-to-grave environmental impact of this drug, it was better than for nitrous oxide when looking specifically at climate-change impact. That might be another reason, another line of argument, that could be put forward in the United States to say, “We want to have a healthy environment and a healthy option for patients.”

I’ll let Sergey speak to mechanisms of action and those types of things.

Dr. Motov: As a general anesthetic and hydrocarbonated volatile ones, I’m just going to say that it causes this generalized diffuse cortical depression, and there are no particular channels, receptors, or enzymes we need to worry much about. In short, it’s an inhaled gas used to put patients or people to sleep.

Over the past 30 or 40 years — and I’ll go back to the past decade — there have been numerous studies in different countries (outside of the United States, of course), and with the recent study that Ken just cited, there were comparisons for managing predominantly acute traumatic injuries in pediatric and adult populations presenting to EDs in various regions of the world that compared Penthrox, or the green whistle, with either placebo or active comparators, which included parenteral opioids, oral opioids, and NSAIDs.

The recent systematic review by Fabbri, out of Italy, showed that for ultra–short-term pain — we’re talking about 5, 10, or 15 minutes — inhaled methoxyflurane was found to be equal or even superior to standard of care, primarily related to parenteral opioids, and safety was off the hook. Interestingly, with respect to analgesia, they found that geriatric patients seemed to be responding more, with respect to changing pain score, than younger adults — we’re talking about ages 18-64 vs 65 or older. Again, we need to make sure that we carefully select those elderly people without underlying renal or hepatic insufficiency.

To wrap this up, there is evidence clearly supporting its analgesic efficacy and safety, even in comparison to commonly used and traditionally accepted analgesic modalities that we use for managing acute pain.

US Military Use and Implications for Civilian Practice

Dr. Glatter: Do you think that methoxyflurane’s use in the military will help propel its use in clinical settings in the US, and possibly convince the FDA to look at this closer? The military is currently using it in deployed combat veterans in an ongoing fashion.

Dr. Motov: I’m excited that the Department of Defense in the United States has taken the lead, and they’re being very progressive. There are data that we’ve adapted to the civilian environment by use of intranasal opioids and intranasal ketamine with more doctors who came out of the military. In the military, it’s a kingdom within a kingdom. I don’t know their relationship with the FDA, but I support the military’s pharmacologic initiative by honoring and disseminating their research once it becomes available.

For us nonmilitary folks, we still need to work with the FDA. We need to convince the FDA to let us study the drug, and then we need to pile the evidence within the United States so that the FDA will start looking at this favorably. It wouldn’t hurt and it wouldn’t harm. Any piece of evidence will add to the existing body of literature that we need to allow this medication to be available to us.

Safety Considerations and Aerosolization Concerns

Dr. Glatter: Its safety in children is well established in Australia and throughout the world. I think it deserves a careful look, and the evidence that you’ve both presented argues for the use of this prehospital but also in hospital. I guess there was concern in the hospital with underventilation and healthcare workers being exposed to the fumes, and then getting headaches, dizziness, and so forth. I don’t know if that’s borne out, Ken, in any of your experience in Canada at all.

Dr. Milne: We currently don’t have it in our shop. It’s being used in British Columbia right now in the prehospital setting, and I’m not aware of anybody using it in their department. It’s used prehospital as far as I know.

Dr. Motov: I can attest to it, if I may, because I had familiarized myself with the device. I actually was able to hold it in my hands. I have not used it yet but I had the prototype. The way it’s set up, there is an activated charcoal chamber that sits right on top of the device, which serves as the scavenger for exhaled air that contains particles of methoxyflurane. In theory, but I’m telling how it is in practicality, it significantly reduces occupational exposure, based on data that lacks specifics.

Although most of the researchers did not measure the concentration of methoxyflurane in ambient air within the treatment room in the EDs, I believe the additional data sources clearly stating that it’s within or even below the detectable level that would cause any harm. Once again, we need to honor pathology. We need to make sure that pregnant women will not be exposed to it.

Dr. Milne: In 2024, we also need to be concerned about aerosolizing procedures and aerosolizing treatments, and just take that into account because we should be considering all the potential benefits and all the potential harms. Going through the COVID-19 pandemic, there was concern about transmission and whether or not it was droplet or aerosolized.

There was an observational study published in 2022 in Austria by Trimmel in BMC Emergency Medicine showing similar results. It seemed to work well and potential harms didn’t get picked up. They had to stop the study early because of COVID-19.

We need to always focus in on the potential benefits, the potential harms; where does the science land? Where do the data lie? Then we move forward from that and make informed decisions.

Final Thoughts

Dr. Glatter: Are there any key takeaways you’d like to share with our audience?

Dr. Milne: One of the takeaways from this whole conversation is that science is iterative and science changes. When new evidence becomes available, and we’ve seen it accumulate around the world, we as scientists, as a researcher, as somebody committed to great patient care should revisit our positions on this. Since there is a prohibition against this medication, I think it’s time to reassess that stance and move forward to see if it still is accurate today.

Dr. Motov: I wholeheartedly agree with this. Thank you, Ken, for bringing this up. Good point.

Dr. Glatter: This has been a really informative discussion. I think our audience will certainly embrace this. Thank you very much for your time; it’s much appreciated.
 

Dr. Glatter is an assistant professor of emergency medicine at Zucker School of Medicine at Hofstra/Northwell in Hempstead, New York. He is a medical adviser for Medscape and hosts the Hot Topics in EM series. Dr. Milne is an emergency physician at Strathroy Middlesex General Hospital in Ontario, Canada, and the founder of the well-known podcast The Skeptics’ Guide to Emergency Medicine (SGEM). Dr. Motov is professor of emergency medicine and director of research in the Department of Emergency Medicine at Maimonides Medical Center in Brooklyn, New York. He is passionate about safe and effective pain management in the emergency department, and has numerous publications on the subject of opioid alternatives in pain management. Dr. Glatter, Dr. Milne, and Dr. Motov had no conflicts of interest to disclose.

A version of this article appeared on Medscape.com.

This discussion was recorded on March 29, 2024. The transcript has been edited for clarity.

Robert D. Glatter, MD: Joining me today to discuss the use of methoxyflurane (Penthrox), an inhaled nonopioid analgesic for the relief of acute pain, is Dr. William Kenneth (Ken) Milne, an emergency physician at Strathroy Middlesex General Hospital in Ontario, Canada, and the founder of the well-known podcast The Skeptics’ Guide to Emergency Medicine (SGEM).

Also joining me is Dr. Sergey Motov, an emergency physician and research director at Maimonides Medical Center in Brooklyn, New York, and an expert in pain management. I want to welcome both of you and thank you for joining me.
 

RAMPED Trial: Evaluating the Efficacy of Methoxyflurane

Dr. Glatter: Ken, your recent post on Twitter [now X] regarding the utility of Penthrox in the RAMPED trial really caught my attention. While the trial was from 2021, it really is relevant regarding the prehospital management of pain in the practice of emergency medicine, and certainly in-hospital practice. I was hoping you could review the study design but also get into the rationale behind the use of this novel agent.

William Kenneth (Ken) Milne, MD, MSc: Sure. I’d be happy to kick this episode off with talking about a study that was published in 2020 in Academic Emergency Medicine. It was an Australian study by Brichko et al., and they were doing a randomized controlled trial looking at methoxyflurane vs standard care.

They selected out a population of adults, which they defined as 18-75 years of age. They were in the prehospital setting and they had a pain score of greater than 8. They gave the participants methoxyflurane, which is also called the “green whistle.” They had the subjects take that for their prehospital pain, and they compared that with whatever your standard analgesic in the prehospital setting would be.

Their primary outcome was how many patients had at least 50% reduction in their pain score within 30 minutes. They recruited about 120 people, and they found that there was no statistical difference in the primary outcome between methoxyflurane and standard care. Again, that primary outcome was a reduction in pain score by greater than 50% at 30 minutes, and there wasn’t a statistical difference between the two.

There are obviously limits to any study, and it was a convenience sample. This was an unmasked trial, so people knew if they were getting this green whistle, which is popular in Australia. People would be familiar with this device, and they didn’t compare it with a sham or placebo group.

Pharmacology of Penthrox: Its Role and Mechanism of Action

Dr. Glatter: The primary outcome wasn’t met, but certainly secondary outcomes were. There was, again, a relatively small number of patients in this trial. That said, there was significant pain relief. I think there are issues with the trial, as with any trial limitations.

Getting to the pharmacology of Penthrox, can you describe this inhaled anesthetic and how we use it, specifically its role at the subanesthetic doses?

Sergey M. Motov, MD: Methoxyflurane is embedded in the green whistle package, and that whole contraption is called Penthrox. It’s an inhaled volatile fluorinated hydrocarbon anesthetic that was predominantly used, I’d say 40, 50 years ago, for general anesthesia and slowly but surely fell out of favor due to the fact that, when used for prolonged duration or in supratherapeutic doses, there were cases of severe or even fatal nephrotoxicity and hepatotoxicity.

In the late ‘70s and early ‘80s, all the fluranes came on board that are slightly different as general anesthetics, and methoxyflurane started slowly falling out of favor. Because of this paucity and then a subsequent slightly greater number of cases of nephrotoxicity and hepatotoxicity, [the US Food and Drug Administration] FDA made a decision to pull the drug off the market in 2005. FDA successfully accomplished its mission and since then has pretty much banned the use of inhaled methoxyflurane in any shape, form, or color in the United States.

Going back to the green whistle, it has been used in Australia probably for about 50-60 years, and has been used in Europe for probably 10-20 years. Ken can attest that it has been used in Canada for at least a decade and the track record is phenomenal.

We are using subanesthetic, even supratherapeutic doses that, based on available literature, has no incidence of this fatal hepatotoxicity or nephrotoxicity. We’re talking about 10 million doses administered worldwide, except in the United States. There are 40-plus randomized clinical trials with over 30,000 patients enrolled that prove efficacy and safety.

That’s where we are right now, in a conundrum. We have a great deal of data all over the world, except in the United States, that push for the use of this noninvasive, patient-controlled nonopioid inhaled anesthetic. We just don’t have the access in North America, with the exception of Canada.

Regulatory Hurdles: Challenges in FDA Approval

Dr. Glatter: Absolutely. The FDA wants to be cautious, but if you look at the evidence base of data on this, it really indicates otherwise. Do you think that these roadblocks can be somehow overcome?

Dr. Milne: In the 2000s and 2010s, everybody was focused on opioids and all the dangers and potential adverse events. Opioids are great drugs like many other drugs; it depends on dose and duration. If used properly, it’s an excellent drug. Well, here’s another excellent drug if it’s used properly, and the adverse events are dependent on their dose and duration. Penthrox, or methoxyflurane, is a subtherapeutic, small dose and there have been no reported cases of addiction or abuse related to these inhalers.

Dr. Glatter: That argues for the point — and I’ll turn this over to you, Sergey — of how can this not, in my mind, be an issue that the FDA can overcome.

Dr. Motov: I agree with you. It’s very hard for me to speak on behalf of the FDA, to allude to their thinking processes, but we need to be up to speed with the evidence. The first thing is, why don’t you study the drug in the United States? I’m not asking you to lift the ban, which you put in 2005, but why don’t you honor what has been done over two decades and at least open the door a little bit and let us do what we do best? Why don’t you allow us to do the research in a controlled setting with a carefully, properly selected group of patients without underlying renal or hepatic insufficiency and see where we’re at?

Let’s compare it against placebo. If that’s not ethical, let’s compare it against active comparators — God knows we have 15-20 drugs we can use — and let’s see where we’re at. Ken has been nothing short of superb when it comes to evidence. Let us put the evidence together.

Dr. Milne: If there were concerns decades ago, those need to be addressed. As science is iterative and as other information becomes available, the scientific method would say, Let’s reexamine this and let’s reexamine our position, and do that with evidence. To do that, it has to have validity within the US system. Someone like you doing the research, you are a pain research guru; you should be doing this research to say, “Does it work or not? Does this nonapproval still stand today in 2024?”

Dr. Motov: Thank you for the shout-out, and I agree with you. All of us, those who are interested, on the frontiers of emergency care — as present clinicians — we should be doing this. There is nothing that will convince the FDA more than properly and rightly conducted research, time to reassess the evidence, and time to be less rigid. I understand that you placed a ban 20 years ago, but let’s go with the science. We cannot be behind it.

Exploring the Ecological Footprint of Methoxyflurane

Dr. Milne: There was an Austrian study in 2022 and a very interesting study out of the UK looking at life-cycle impact assessment on the environment. If we’re not just concerned about patient care —obviously, we want to provide patients with a safe and effective product, compared with other products that are available that might not have as good a safety profile — this looks at the impact on the environment.

Dr. Glatter: Ken, can you tell me about some of your recent research regarding the environmental effects related to use of Penthrox, but also its utility pharmacologically and its mechanism of action?

Dr. Milne: There was a really interesting study published this year by Martindale in the Emergency Medicine Journal. It took a different approach to this question about could we be using this drug, and why should we be using this drug? Sergey and I have already talked about the potential benefits and the potential harms. I mentioned opioids and some of the concerns about that. For this drug, if we’re using it in the prehospital setting in this little green whistle, the potential benefits look really good, and we haven’t seen any of the potential harms come through in the literature.

This was another line of evidence of why this might be a good drug, because of the environmental impact of this low-dose methoxyflurane. They compared it with nitrous oxide and said, “Well, what about the life-cycle impact on the environment of using this and the overall cradle-to-grave environmental impacts?”

Obviously, Sergey and I are interested in patient care, and we treat patients one at a time. But we have a larger responsibility to social determinants of health, like our environment. If you look at the overall cradle-to-grave environmental impact of this drug, it was better than for nitrous oxide when looking specifically at climate-change impact. That might be another reason, another line of argument, that could be put forward in the United States to say, “We want to have a healthy environment and a healthy option for patients.”

I’ll let Sergey speak to mechanisms of action and those types of things.

Dr. Motov: As a general anesthetic and hydrocarbonated volatile ones, I’m just going to say that it causes this generalized diffuse cortical depression, and there are no particular channels, receptors, or enzymes we need to worry much about. In short, it’s an inhaled gas used to put patients or people to sleep.

Over the past 30 or 40 years — and I’ll go back to the past decade — there have been numerous studies in different countries (outside of the United States, of course), and with the recent study that Ken just cited, there were comparisons for managing predominantly acute traumatic injuries in pediatric and adult populations presenting to EDs in various regions of the world that compared Penthrox, or the green whistle, with either placebo or active comparators, which included parenteral opioids, oral opioids, and NSAIDs.

The recent systematic review by Fabbri, out of Italy, showed that for ultra–short-term pain — we’re talking about 5, 10, or 15 minutes — inhaled methoxyflurane was found to be equal or even superior to standard of care, primarily related to parenteral opioids, and safety was off the hook. Interestingly, with respect to analgesia, they found that geriatric patients seemed to be responding more, with respect to changing pain score, than younger adults — we’re talking about ages 18-64 vs 65 or older. Again, we need to make sure that we carefully select those elderly people without underlying renal or hepatic insufficiency.

To wrap this up, there is evidence clearly supporting its analgesic efficacy and safety, even in comparison to commonly used and traditionally accepted analgesic modalities that we use for managing acute pain.

US Military Use and Implications for Civilian Practice

Dr. Glatter: Do you think that methoxyflurane’s use in the military will help propel its use in clinical settings in the US, and possibly convince the FDA to look at this closer? The military is currently using it in deployed combat veterans in an ongoing fashion.

Dr. Motov: I’m excited that the Department of Defense in the United States has taken the lead, and they’re being very progressive. There are data that we’ve adapted to the civilian environment by use of intranasal opioids and intranasal ketamine with more doctors who came out of the military. In the military, it’s a kingdom within a kingdom. I don’t know their relationship with the FDA, but I support the military’s pharmacologic initiative by honoring and disseminating their research once it becomes available.

For us nonmilitary folks, we still need to work with the FDA. We need to convince the FDA to let us study the drug, and then we need to pile the evidence within the United States so that the FDA will start looking at this favorably. It wouldn’t hurt and it wouldn’t harm. Any piece of evidence will add to the existing body of literature that we need to allow this medication to be available to us.

Safety Considerations and Aerosolization Concerns

Dr. Glatter: Its safety in children is well established in Australia and throughout the world. I think it deserves a careful look, and the evidence that you’ve both presented argues for the use of this prehospital but also in hospital. I guess there was concern in the hospital with underventilation and healthcare workers being exposed to the fumes, and then getting headaches, dizziness, and so forth. I don’t know if that’s borne out, Ken, in any of your experience in Canada at all.

Dr. Milne: We currently don’t have it in our shop. It’s being used in British Columbia right now in the prehospital setting, and I’m not aware of anybody using it in their department. It’s used prehospital as far as I know.

Dr. Motov: I can attest to it, if I may, because I had familiarized myself with the device. I actually was able to hold it in my hands. I have not used it yet but I had the prototype. The way it’s set up, there is an activated charcoal chamber that sits right on top of the device, which serves as the scavenger for exhaled air that contains particles of methoxyflurane. In theory, but I’m telling how it is in practicality, it significantly reduces occupational exposure, based on data that lacks specifics.

Although most of the researchers did not measure the concentration of methoxyflurane in ambient air within the treatment room in the EDs, I believe the additional data sources clearly stating that it’s within or even below the detectable level that would cause any harm. Once again, we need to honor pathology. We need to make sure that pregnant women will not be exposed to it.

Dr. Milne: In 2024, we also need to be concerned about aerosolizing procedures and aerosolizing treatments, and just take that into account because we should be considering all the potential benefits and all the potential harms. Going through the COVID-19 pandemic, there was concern about transmission and whether or not it was droplet or aerosolized.

There was an observational study published in 2022 in Austria by Trimmel in BMC Emergency Medicine showing similar results. It seemed to work well and potential harms didn’t get picked up. They had to stop the study early because of COVID-19.

We need to always focus in on the potential benefits, the potential harms; where does the science land? Where do the data lie? Then we move forward from that and make informed decisions.

Final Thoughts

Dr. Glatter: Are there any key takeaways you’d like to share with our audience?

Dr. Milne: One of the takeaways from this whole conversation is that science is iterative and science changes. When new evidence becomes available, and we’ve seen it accumulate around the world, we as scientists, as a researcher, as somebody committed to great patient care should revisit our positions on this. Since there is a prohibition against this medication, I think it’s time to reassess that stance and move forward to see if it still is accurate today.

Dr. Motov: I wholeheartedly agree with this. Thank you, Ken, for bringing this up. Good point.

Dr. Glatter: This has been a really informative discussion. I think our audience will certainly embrace this. Thank you very much for your time; it’s much appreciated.
 

Dr. Glatter is an assistant professor of emergency medicine at Zucker School of Medicine at Hofstra/Northwell in Hempstead, New York. He is a medical adviser for Medscape and hosts the Hot Topics in EM series. Dr. Milne is an emergency physician at Strathroy Middlesex General Hospital in Ontario, Canada, and the founder of the well-known podcast The Skeptics’ Guide to Emergency Medicine (SGEM). Dr. Motov is professor of emergency medicine and director of research in the Department of Emergency Medicine at Maimonides Medical Center in Brooklyn, New York. He is passionate about safe and effective pain management in the emergency department, and has numerous publications on the subject of opioid alternatives in pain management. Dr. Glatter, Dr. Milne, and Dr. Motov had no conflicts of interest to disclose.

A version of this article appeared on Medscape.com.

TOPLINE:

The recommended 10-year interval between screening colonoscopies may be safely extended to 15 years in adults with no family history of colorectal cancer (CRC) whose first colonoscopy is negative for CRC, a population-based study suggests.

METHODOLOGY:

• Using Swedish nationwide registry data, researchers compared 110,074 individuals who had a first colonoscopy with negative findings for CRC at age 45-69 years (exposed group) with more than 1.9 million matched controls who either did not have a colonoscopy during the study period or underwent colonoscopy that led to a CRC diagnosis.
• They calculated 10-year standardized incidence ratio (SIR) and standardized mortality ratio (SMR) to compare risks for CRC and CRC-specific death in the exposed and control groups based on different follow-up screening intervals.

TAKEAWAY:

• During up to 29 years of follow-up, 484 incident CRCs and 112 CRC deaths occurred in the group with a negative initial colonoscopy.
• Up to 15 years after negative colonoscopy, the 10-year cumulative risk for CRC and CRC mortality was lower than in the control group, with an SIR of 0.72 and SMR of 0.55, respectively.
• Extending the screening interval from 10 to 15 years would miss early detection of only two CRC cases and prevention of only one CRC death per 1000 individuals, while potentially avoiding 1000 colonoscopies.

IN PRACTICE:

“This study provides evidence for recommending a longer colonoscopy screening interval than what is currently recommended in most guidelines for populations with no familial risk of CRC,” the authors wrote. “A longer interval between colonoscopy screenings could be beneficial in avoiding unnecessary invasive examinations.”

SOURCE:

The study, with first author Qunfeng Liang, MSc, with the German Cancer Research Center, Heidelberg, Germany, was published online on May 2 in JAMA Oncology.

LIMITATIONS:

The study population primarily included White individuals, particularly ethnic Swedish individuals, so external validation would be necessary to generalize the recommendation to other populations. The researchers lacked data on non-endoscopic tests, such as fecal occult blood tests, which could have been performed as a substitution for colonoscopy during the interval between colonoscopy screenings.

DISCLOSURES:

The study had no specific funding. The authors had no relevant conflicts of interest.

A version of this article appeared on Medscape.com.

TOPLINE:

The recommended 10-year interval between screening colonoscopies may be safely extended to 15 years in adults with no family history of colorectal cancer (CRC) whose first colonoscopy is negative for CRC, a population-based study suggests.

METHODOLOGY:

• Using Swedish nationwide registry data, researchers compared 110,074 individuals who had a first colonoscopy with negative findings for CRC at age 45-69 years (exposed group) with more than 1.9 million matched controls who either did not have a colonoscopy during the study period or underwent colonoscopy that led to a CRC diagnosis.
• They calculated 10-year standardized incidence ratio (SIR) and standardized mortality ratio (SMR) to compare risks for CRC and CRC-specific death in the exposed and control groups based on different follow-up screening intervals.

TAKEAWAY:

• During up to 29 years of follow-up, 484 incident CRCs and 112 CRC deaths occurred in the group with a negative initial colonoscopy.
• Up to 15 years after negative colonoscopy, the 10-year cumulative risk for CRC and CRC mortality was lower than in the control group, with an SIR of 0.72 and SMR of 0.55, respectively.
• Extending the screening interval from 10 to 15 years would miss early detection of only two CRC cases and prevention of only one CRC death per 1000 individuals, while potentially avoiding 1000 colonoscopies.

IN PRACTICE:

“This study provides evidence for recommending a longer colonoscopy screening interval than what is currently recommended in most guidelines for populations with no familial risk of CRC,” the authors wrote. “A longer interval between colonoscopy screenings could be beneficial in avoiding unnecessary invasive examinations.”

SOURCE:

The study, with first author Qunfeng Liang, MSc, with the German Cancer Research Center, Heidelberg, Germany, was published online on May 2 in JAMA Oncology.

LIMITATIONS:

The study population primarily included White individuals, particularly ethnic Swedish individuals, so external validation would be necessary to generalize the recommendation to other populations. The researchers lacked data on non-endoscopic tests, such as fecal occult blood tests, which could have been performed as a substitution for colonoscopy during the interval between colonoscopy screenings.

DISCLOSURES:

The study had no specific funding. The authors had no relevant conflicts of interest.

A version of this article appeared on Medscape.com.

TOPLINE:

The recommended 10-year interval between screening colonoscopies may be safely extended to 15 years in adults with no family history of colorectal cancer (CRC) whose first colonoscopy is negative for CRC, a population-based study suggests.

METHODOLOGY:

• Using Swedish nationwide registry data, researchers compared 110,074 individuals who had a first colonoscopy with negative findings for CRC at age 45-69 years (exposed group) with more than 1.9 million matched controls who either did not have a colonoscopy during the study period or underwent colonoscopy that led to a CRC diagnosis.
• They calculated 10-year standardized incidence ratio (SIR) and standardized mortality ratio (SMR) to compare risks for CRC and CRC-specific death in the exposed and control groups based on different follow-up screening intervals.

TAKEAWAY:

• During up to 29 years of follow-up, 484 incident CRCs and 112 CRC deaths occurred in the group with a negative initial colonoscopy.
• Up to 15 years after negative colonoscopy, the 10-year cumulative risk for CRC and CRC mortality was lower than in the control group, with an SIR of 0.72 and SMR of 0.55, respectively.
• Extending the screening interval from 10 to 15 years would miss early detection of only two CRC cases and prevention of only one CRC death per 1000 individuals, while potentially avoiding 1000 colonoscopies.

IN PRACTICE:

“This study provides evidence for recommending a longer colonoscopy screening interval than what is currently recommended in most guidelines for populations with no familial risk of CRC,” the authors wrote. “A longer interval between colonoscopy screenings could be beneficial in avoiding unnecessary invasive examinations.”

SOURCE:

The study, with first author Qunfeng Liang, MSc, with the German Cancer Research Center, Heidelberg, Germany, was published online on May 2 in JAMA Oncology.

LIMITATIONS:

The study population primarily included White individuals, particularly ethnic Swedish individuals, so external validation would be necessary to generalize the recommendation to other populations. The researchers lacked data on non-endoscopic tests, such as fecal occult blood tests, which could have been performed as a substitution for colonoscopy during the interval between colonoscopy screenings.

DISCLOSURES:

The study had no specific funding. The authors had no relevant conflicts of interest.

A version of this article appeared on Medscape.com.

TOPLINE:

Overall, patients with solid tumors who receive an investigational cancer drug experience small progression-free survival (PFS) and overall survival benefits but much higher toxicity than those who receive a control intervention.

METHODOLOGY:

• The view that patients with cancer benefit from access to investigational drugs in the clinical trial setting is widely held but does necessarily align with trial findings, which often show limited evidence of a clinical benefit. First, most investigational treatments assessed in clinical trials fail to gain regulatory approval, and the minority that are approved tend to offer minimal clinical benefit, experts explained.
• To estimate the survival benefit and toxicities associated with receiving experimental treatments, researchers conducted a meta-analysis of 128 trials comprising 141 comparisons of an investigational drug and a control treatment, which included immunotherapies and targeted therapies.
• The analysis included 42 trials in non–small cell lung cancer (NSCLC), 37 in breast cancer, 15 in hepatobiliary cancer, 13 in pancreatic cancer, 12 in colorectal cancer, and 10 in prostate cancer, involving a total of 47,050 patients.
• The primary outcome was PFS and secondary outcomes were overall survival and grades 3-5 serious adverse events.

TAKEAWAY:

• Overall, the experimental treatment was associated with a 20% improvement in PFS (pooled hazard ratio [HR], 0.80), corresponding to a median 1.25-month PFS advantage. The PFS benefit was seen across all cancer types, except pancreatic cancer.
• Overall survival improved by 8% with experimental agents (HR, 0.92), corresponding to 1.18 additional months. A significant overall survival benefit was seen across NSCLC, breast cancer, and hepatobiliary cancer trials but not pancreatic, prostate, colorectal cancer trials.
• Patients in the experimental intervention group, however, experienced much higher risk for grade 3-5 serious adverse events (risk ratio [RR], 1.27), corresponding to 7.40% increase in absolute risk. The greater risk for serious adverse events was significant for all indications except prostate cancer (RR, 1.13; 95% CI, 0.91-1.40).

IN PRACTICE:

“We believe our findings are best interpreted as suggesting that access to experimental interventions that have not yet received full FDA approval is associated with a marginal but nonzero clinical benefit,” the authors wrote. 

“Although our findings seem to reflect poorly on trials as a vehicle for extending survival for participants, they have reassuring implications for clinical investigators, policymakers, and institutional review boards,” the researchers said, explaining that this “scenario allows clinical trials to continue to pursue promising new treatments — supporting incremental advances that sum to large gains over extended periods of research — without disadvantaging patients in comparator groups.”

SOURCE: 

Renata Iskander, MSc, of McGill University, Montreal, Quebec, Canada, led this work, which was published online on April 29, 2024, in Annals of Internal Medicine.

LIMITATIONS:

There was high heterogeneity across studies due to variations in drugs tested, comparators used, and populations involved. The use of comparators below standard care could have inflated survival benefits. Additionally, data collected from ClinicalTrials.gov might be biased due to some trials not being reported. 

DISCLOSURES:

Canadian Institutes of Health Research supported this work. The authors received grants for this work from McGill University, Rossy Cancer Network, and National Science Foundation. One author received consulting fees outside this work. The other authors declared no competing interests.

A version of this article appeared on Medscape.com.

TOPLINE:

Overall, patients with solid tumors who receive an investigational cancer drug experience small progression-free survival (PFS) and overall survival benefits but much higher toxicity than those who receive a control intervention.

METHODOLOGY:

• The view that patients with cancer benefit from access to investigational drugs in the clinical trial setting is widely held but does necessarily align with trial findings, which often show limited evidence of a clinical benefit. First, most investigational treatments assessed in clinical trials fail to gain regulatory approval, and the minority that are approved tend to offer minimal clinical benefit, experts explained.
• To estimate the survival benefit and toxicities associated with receiving experimental treatments, researchers conducted a meta-analysis of 128 trials comprising 141 comparisons of an investigational drug and a control treatment, which included immunotherapies and targeted therapies.
• The analysis included 42 trials in non–small cell lung cancer (NSCLC), 37 in breast cancer, 15 in hepatobiliary cancer, 13 in pancreatic cancer, 12 in colorectal cancer, and 10 in prostate cancer, involving a total of 47,050 patients.
• The primary outcome was PFS and secondary outcomes were overall survival and grades 3-5 serious adverse events.

TAKEAWAY:

• Overall, the experimental treatment was associated with a 20% improvement in PFS (pooled hazard ratio [HR], 0.80), corresponding to a median 1.25-month PFS advantage. The PFS benefit was seen across all cancer types, except pancreatic cancer.
• Overall survival improved by 8% with experimental agents (HR, 0.92), corresponding to 1.18 additional months. A significant overall survival benefit was seen across NSCLC, breast cancer, and hepatobiliary cancer trials but not pancreatic, prostate, colorectal cancer trials.
• Patients in the experimental intervention group, however, experienced much higher risk for grade 3-5 serious adverse events (risk ratio [RR], 1.27), corresponding to 7.40% increase in absolute risk. The greater risk for serious adverse events was significant for all indications except prostate cancer (RR, 1.13; 95% CI, 0.91-1.40).

IN PRACTICE:

“We believe our findings are best interpreted as suggesting that access to experimental interventions that have not yet received full FDA approval is associated with a marginal but nonzero clinical benefit,” the authors wrote. 

“Although our findings seem to reflect poorly on trials as a vehicle for extending survival for participants, they have reassuring implications for clinical investigators, policymakers, and institutional review boards,” the researchers said, explaining that this “scenario allows clinical trials to continue to pursue promising new treatments — supporting incremental advances that sum to large gains over extended periods of research — without disadvantaging patients in comparator groups.”

SOURCE: 

Renata Iskander, MSc, of McGill University, Montreal, Quebec, Canada, led this work, which was published online on April 29, 2024, in Annals of Internal Medicine.

LIMITATIONS:

There was high heterogeneity across studies due to variations in drugs tested, comparators used, and populations involved. The use of comparators below standard care could have inflated survival benefits. Additionally, data collected from ClinicalTrials.gov might be biased due to some trials not being reported. 

DISCLOSURES:

Canadian Institutes of Health Research supported this work. The authors received grants for this work from McGill University, Rossy Cancer Network, and National Science Foundation. One author received consulting fees outside this work. The other authors declared no competing interests.

A version of this article appeared on Medscape.com.

TOPLINE:

Overall, patients with solid tumors who receive an investigational cancer drug experience small progression-free survival (PFS) and overall survival benefits but much higher toxicity than those who receive a control intervention.

METHODOLOGY:

• The view that patients with cancer benefit from access to investigational drugs in the clinical trial setting is widely held but does necessarily align with trial findings, which often show limited evidence of a clinical benefit. First, most investigational treatments assessed in clinical trials fail to gain regulatory approval, and the minority that are approved tend to offer minimal clinical benefit, experts explained.
• To estimate the survival benefit and toxicities associated with receiving experimental treatments, researchers conducted a meta-analysis of 128 trials comprising 141 comparisons of an investigational drug and a control treatment, which included immunotherapies and targeted therapies.
• The analysis included 42 trials in non–small cell lung cancer (NSCLC), 37 in breast cancer, 15 in hepatobiliary cancer, 13 in pancreatic cancer, 12 in colorectal cancer, and 10 in prostate cancer, involving a total of 47,050 patients.
• The primary outcome was PFS and secondary outcomes were overall survival and grades 3-5 serious adverse events.

TAKEAWAY:

• Overall, the experimental treatment was associated with a 20% improvement in PFS (pooled hazard ratio [HR], 0.80), corresponding to a median 1.25-month PFS advantage. The PFS benefit was seen across all cancer types, except pancreatic cancer.
• Overall survival improved by 8% with experimental agents (HR, 0.92), corresponding to 1.18 additional months. A significant overall survival benefit was seen across NSCLC, breast cancer, and hepatobiliary cancer trials but not pancreatic, prostate, colorectal cancer trials.
• Patients in the experimental intervention group, however, experienced much higher risk for grade 3-5 serious adverse events (risk ratio [RR], 1.27), corresponding to 7.40% increase in absolute risk. The greater risk for serious adverse events was significant for all indications except prostate cancer (RR, 1.13; 95% CI, 0.91-1.40).

IN PRACTICE:

“We believe our findings are best interpreted as suggesting that access to experimental interventions that have not yet received full FDA approval is associated with a marginal but nonzero clinical benefit,” the authors wrote. 

“Although our findings seem to reflect poorly on trials as a vehicle for extending survival for participants, they have reassuring implications for clinical investigators, policymakers, and institutional review boards,” the researchers said, explaining that this “scenario allows clinical trials to continue to pursue promising new treatments — supporting incremental advances that sum to large gains over extended periods of research — without disadvantaging patients in comparator groups.”

SOURCE: 

Renata Iskander, MSc, of McGill University, Montreal, Quebec, Canada, led this work, which was published online on April 29, 2024, in Annals of Internal Medicine.

LIMITATIONS:

There was high heterogeneity across studies due to variations in drugs tested, comparators used, and populations involved. The use of comparators below standard care could have inflated survival benefits. Additionally, data collected from ClinicalTrials.gov might be biased due to some trials not being reported. 

DISCLOSURES:

Canadian Institutes of Health Research supported this work. The authors received grants for this work from McGill University, Rossy Cancer Network, and National Science Foundation. One author received consulting fees outside this work. The other authors declared no competing interests.

A version of this article appeared on Medscape.com.

Up to 60% of men with erectile dysfunction who were not candidates for phosphodiesterase 5 (PDE5) inhibitors achieved erections in less than 10 minutes after a single application of a first-on-the-market nonprescription gel to the glans, a new study found. 

Wayne Hellstrom, MD, chief of andrology at Tulane School of Medicine in New Orleans, who presented the study of MED3000 [Eroxon] on May 5 at the 2024 annual meeting of the American Urological Association in San Antonio, Texas, said that the gel is considered to be a device by the US Food and Drug Administration (FDA). The agency approved the product in June 2023.

A spokesman for Futura, which makes MED3000, said that the gel will be on the market 2025. No price for the United States has been announced, but a four-pack of single-use tubes sells for the equivalent of roughly $31 in the United Kingdom.

Dr. Hellstrom, a former adviser to Futura, he said he expects MED3000 will be “a potential first-line therapy in addition to PDE5 inhibitors,” which are vasodilating drugs that stimulate the corpora cavernosa of the penis, facilitating erection with sexual stimulation.

He noted that PDE5s are contraindicated for many men; are not tolerated in others; are not completely effective; or work too slowly, taking 1-2 hours to work. As a result, up to 50% of patients cease using a PDE5 inhibitor within 1 year, he said. 

Futura said the gel contains a combination of volatile solvents which, when applied to the head of the penis, evaporate rapidly, stimulating nerve endings through an initial cooling effect followed by a warming sensation. This reaction releases nitric oxide, relaxing the smooth muscle tissue inside the penis and increasing blood flow that is needed to obtain an erection.

Dr. Hellstrom noted that MED3000 is noninvasive and causes no side effects and is slightly more effective if applied by a partner.

The new findings come from two studies of 250 men with erectile dysfunction (FM57) who used MED3000 over 12 weeks and a randomly assigned arm (FM71) with two groups of 48 men who used either MED3000 or 5 mg of tadalafil over 24 weeks.

Erections were achieved in less than 10 minutes in 60.1% of men in the FM57 group and 44.9% of those in the FM71 group.

Overall, less than 2% of the men who usedMED3000 and 4% of those who took tadalafil reported adverse effects. These events included headaches in 3% of the combined MED3000 group and 19.1% of the tadalafil group. Roughly 1% of men who used MED3000 reported penile burning sensation compared with none in the group taking tadalafil.
 

Problematic Design? 

Kevin McVary, MD, a professor of urology at Stritch School of Medicine of Loyola University, outside of Chicago, and director of the Center for Male Health, criticized the study design and added that he did not believe MED3000 had been proven beneficial.

“Are they expecting the Cialis 5 mg to work within 10 minutes? Because it doesn’t,” Dr. McVary said. “It doesn’t get absorbed into the bloodstream for about 2.5 hours.”

Dr. McVary said that men with erectile dysfunction will probably do anything to avoid seeing a physician about the condition, which could make MED3000 highly marketable.

However, he said, examinations would be important to detect unrecognized underlying cardiac disease, especially in younger men. “ED can function as the classic canary in a coal mine where it tells you who’s at risk for unexpected early death,” he said.

Dr. Hellstrom is a former adviser to Futura Medical Developments, which funded the research. Dr. McVary reported no relevant financial conflicts of interest.  
 

A version of this article appeared on Medscape.com .