Immuno-oncology

Sequential chemoradiotherapy (CRT) and immunotherapy is safe, well tolerated, and efficacious among patients with locally advanced cervical cancer being treated with curative intent, a multicenter phase 1 trial suggests.

Less than 10% of patients treated with this sequence experienced a grade 3 toxicity. Meanwhile, more than 80% were alive and free of disease progression at 1 year.

“Despite standard CRT, most women with lymph node–positive cervical cancer experience disease recurrence,” note the investigators, led by Jyoti S. Mayadev, MD, associate professor in the department of radiation medicine and applied sciences, University of California, San Diego, in La Jolla. “Our study is potentially transformative in the standard treatment schema of locally advanced cervical cancer, with the prospect for immuno-oncology to add durable survival in patients with node-positive disease, a current unmet oncologic need.”

The investigators enrolled in the trial 32 women from Gynecology Oncology Cooperative Group member institutions who had stage IB2 to IVA cervical cancer with positive pelvic and/or para-aortic lymph nodes. Treatment consisted of six weekly doses of cisplatin, 40 mg/m², concurrent with extended-field, 3-dimensional conformal radiotherapy, followed by the immune checkpoint inhibitor ipilimumab (Yervoy) every 21 days for four cycles.

Results reported in JAMA Oncology showed that all 32 patients completed CRT and 21 patients went on to receive ipilimumab. Among the latter, 86% completed all four planned cycles and the rest completed two cycles.

In the group receiving sequential CRT and ipilimumab, 9.5% experienced grade 3 toxicity (lipase increase in one case and dermatitis in another case). Both toxicities were self-limited.

With a 14.8-month median follow-up, the patients treated with CRT-ipilimumab had a 12-month overall survival rate of 90%, and a 12-month progression-free survival rate of 81% (median durations were not reached). Neither human papillomavirus genotype nor HLA subtype was associated with these outcomes.

Translational analyses showed that patients experienced an increase in peripheral blood T cells expressing programmed cell death 1 (PD-1) after CRT that was then sustained with ipilimumab therapy. “[T]he use of an immune checkpoint inhibitor could stimulate the antitumor activity of tumor-specific cytotoxic T cells and augment radiation-induced neoantigen load,” the investigators proposed.

“To our knowledge, this phase 1 study is the first to show tolerability with a signal of efficacy of an immune check-point inhibitor ... as a part of the definitive treatment of locally advanced cervical cancer,” they concluded. “Our findings show promise for the use of immunotherapy in the definitive setting of locally advanced, node-positive cervical cancer; patients with this cancer historically have a poor prognosis with standard therapy alone.”

Dr. Mayadev disclosed receiving a grant from the National Cancer Institute during the conduct of the study, personal fees from AstraZeneca, grants from NRG Oncology, and personal fees and nonfinancial support from the Gynecology Oncology Group Foundation outside the submitted work; receiving compensation for serving on the advisory board of Varian Medical Systems in 2018; and being a speaker for Samsung Medical Systems in 2017. The study was supported by the National Cancer Institute and by institutional funds.

SOURCE: Mayadev JS et al. JAMA Oncol. 2019 Nov 27. doi: 10.1001/jamaoncol.2019.3857.

Sequential chemoradiotherapy (CRT) and immunotherapy is safe, well tolerated, and efficacious among patients with locally advanced cervical cancer being treated with curative intent, a multicenter phase 1 trial suggests.

Less than 10% of patients treated with this sequence experienced a grade 3 toxicity. Meanwhile, more than 80% were alive and free of disease progression at 1 year.

“Despite standard CRT, most women with lymph node–positive cervical cancer experience disease recurrence,” note the investigators, led by Jyoti S. Mayadev, MD, associate professor in the department of radiation medicine and applied sciences, University of California, San Diego, in La Jolla. “Our study is potentially transformative in the standard treatment schema of locally advanced cervical cancer, with the prospect for immuno-oncology to add durable survival in patients with node-positive disease, a current unmet oncologic need.”

The investigators enrolled in the trial 32 women from Gynecology Oncology Cooperative Group member institutions who had stage IB2 to IVA cervical cancer with positive pelvic and/or para-aortic lymph nodes. Treatment consisted of six weekly doses of cisplatin, 40 mg/m², concurrent with extended-field, 3-dimensional conformal radiotherapy, followed by the immune checkpoint inhibitor ipilimumab (Yervoy) every 21 days for four cycles.

Results reported in JAMA Oncology showed that all 32 patients completed CRT and 21 patients went on to receive ipilimumab. Among the latter, 86% completed all four planned cycles and the rest completed two cycles.

In the group receiving sequential CRT and ipilimumab, 9.5% experienced grade 3 toxicity (lipase increase in one case and dermatitis in another case). Both toxicities were self-limited.

With a 14.8-month median follow-up, the patients treated with CRT-ipilimumab had a 12-month overall survival rate of 90%, and a 12-month progression-free survival rate of 81% (median durations were not reached). Neither human papillomavirus genotype nor HLA subtype was associated with these outcomes.

Translational analyses showed that patients experienced an increase in peripheral blood T cells expressing programmed cell death 1 (PD-1) after CRT that was then sustained with ipilimumab therapy. “[T]he use of an immune checkpoint inhibitor could stimulate the antitumor activity of tumor-specific cytotoxic T cells and augment radiation-induced neoantigen load,” the investigators proposed.

“To our knowledge, this phase 1 study is the first to show tolerability with a signal of efficacy of an immune check-point inhibitor ... as a part of the definitive treatment of locally advanced cervical cancer,” they concluded. “Our findings show promise for the use of immunotherapy in the definitive setting of locally advanced, node-positive cervical cancer; patients with this cancer historically have a poor prognosis with standard therapy alone.”

Dr. Mayadev disclosed receiving a grant from the National Cancer Institute during the conduct of the study, personal fees from AstraZeneca, grants from NRG Oncology, and personal fees and nonfinancial support from the Gynecology Oncology Group Foundation outside the submitted work; receiving compensation for serving on the advisory board of Varian Medical Systems in 2018; and being a speaker for Samsung Medical Systems in 2017. The study was supported by the National Cancer Institute and by institutional funds.

SOURCE: Mayadev JS et al. JAMA Oncol. 2019 Nov 27. doi: 10.1001/jamaoncol.2019.3857.

Sequential chemoradiotherapy (CRT) and immunotherapy is safe, well tolerated, and efficacious among patients with locally advanced cervical cancer being treated with curative intent, a multicenter phase 1 trial suggests.

Less than 10% of patients treated with this sequence experienced a grade 3 toxicity. Meanwhile, more than 80% were alive and free of disease progression at 1 year.

“Despite standard CRT, most women with lymph node–positive cervical cancer experience disease recurrence,” note the investigators, led by Jyoti S. Mayadev, MD, associate professor in the department of radiation medicine and applied sciences, University of California, San Diego, in La Jolla. “Our study is potentially transformative in the standard treatment schema of locally advanced cervical cancer, with the prospect for immuno-oncology to add durable survival in patients with node-positive disease, a current unmet oncologic need.”

The investigators enrolled in the trial 32 women from Gynecology Oncology Cooperative Group member institutions who had stage IB2 to IVA cervical cancer with positive pelvic and/or para-aortic lymph nodes. Treatment consisted of six weekly doses of cisplatin, 40 mg/m², concurrent with extended-field, 3-dimensional conformal radiotherapy, followed by the immune checkpoint inhibitor ipilimumab (Yervoy) every 21 days for four cycles.

Results reported in JAMA Oncology showed that all 32 patients completed CRT and 21 patients went on to receive ipilimumab. Among the latter, 86% completed all four planned cycles and the rest completed two cycles.

In the group receiving sequential CRT and ipilimumab, 9.5% experienced grade 3 toxicity (lipase increase in one case and dermatitis in another case). Both toxicities were self-limited.

With a 14.8-month median follow-up, the patients treated with CRT-ipilimumab had a 12-month overall survival rate of 90%, and a 12-month progression-free survival rate of 81% (median durations were not reached). Neither human papillomavirus genotype nor HLA subtype was associated with these outcomes.

Translational analyses showed that patients experienced an increase in peripheral blood T cells expressing programmed cell death 1 (PD-1) after CRT that was then sustained with ipilimumab therapy. “[T]he use of an immune checkpoint inhibitor could stimulate the antitumor activity of tumor-specific cytotoxic T cells and augment radiation-induced neoantigen load,” the investigators proposed.

“To our knowledge, this phase 1 study is the first to show tolerability with a signal of efficacy of an immune check-point inhibitor ... as a part of the definitive treatment of locally advanced cervical cancer,” they concluded. “Our findings show promise for the use of immunotherapy in the definitive setting of locally advanced, node-positive cervical cancer; patients with this cancer historically have a poor prognosis with standard therapy alone.”

Dr. Mayadev disclosed receiving a grant from the National Cancer Institute during the conduct of the study, personal fees from AstraZeneca, grants from NRG Oncology, and personal fees and nonfinancial support from the Gynecology Oncology Group Foundation outside the submitted work; receiving compensation for serving on the advisory board of Varian Medical Systems in 2018; and being a speaker for Samsung Medical Systems in 2017. The study was supported by the National Cancer Institute and by institutional funds.

SOURCE: Mayadev JS et al. JAMA Oncol. 2019 Nov 27. doi: 10.1001/jamaoncol.2019.3857.

Chimeric antigen receptor (CAR) T-cell therapies have garnered a great deal of attention given their “incredible efficacy” in treating B-cell malignancies, and new findings are taking aim at the drawbacks of therapy, such as the time, expense, and toxicity involved, according to Robert A. Brodsky, MD.

One example, from a study slated for presentation during a plenary session at the upcoming annual meeting of the American Society of Hematology involves the investigational T-cell bispecific antibody mosunetuzumab, which targets both CD20 on the surface of malignant B cells, and CD3 on cytotoxic T cells, engaging the T cells and directing their cytotoxicity against B cells.

In a study (Abstract 6) of 218 non-Hodgkin lymphoma patients, including 23 who had already received CAR T-cell therapy and had relapsed or were refractory to the treatment, 64% responded, 42% had a complete response, and the median duration of response is now out to 9 months, Dr. Brodsky, ASH secretary and director of the division of hematology at Johns Hopkins University, Baltimore, said during a premeeting press conference.

“It’s basically an antibody using the patient’s own T cell to do what a CAR-T cell would do – [a] very exciting study and large study,” he said. “It is an off-the-shelf product, it completely gets around the problem of the time to generate the CAR T-cell product, and because it’s going to be much simpler and faster to produce, it’s likely going to be much cheaper than CAR T cells.”

The preliminary results also suggest it is less toxic than CAR T-cell therapy, he added.

Two other CAR T-cell therapy–related studies highlighted during the press conference address its use for multiple myeloma. One, the phase 1b/2 CARTITUDE study (Abstract 577) uses CAR T cells against the B-cell maturation antigen (BCMA) in the relapsed/refractory setting.

Of 25 patients treated with chemotherapy followed by CAR T-cell infusion and followed for a median of 3 months, 91% responded, two achieved a complete remission, and “many other responses were very deep responses,” Dr. Brodsky said, noting that the second featured multiple myeloma trial (Abstract 930) looked at bispecific CAR T-cell therapy targeting BCMA and CD38 in an effort to reduce resistance to the therapy.

“Again, very interesting preliminary results,” he said, noting that of 16 patients followed for a median of 36 weeks, 87.5% responded, the treatment was well tolerated, and progression-free survival at 9 months was 75%.

In addition to the “key theme” of overcoming CAR T-cell therapy obstacles, three other themes have emerged from among the thousands of abstracts submitted for presentation at ASH. These, as presented during the press conference, include new venous thromboembolism (VTE) therapies and approaches to research; inclusive medicine, with abstracts focused on age- and race-related issues in clinical trials; and new advances in the treatment of sickle cell disease. All of these have potentially practice-changing implications, as do the six late-breaking abstracts selected from 93 abstracts submitted for consideration for oral presentation at ASH, Dr. Brodsky said.

One of the “truly practice-changing” late-breakers is a randomized phase 3 trial (Abstract LBA-1) comparing the bispecific antibody blinatumomab to chemotherapy for post-re-induction therapy in high- and intermediate-risk acute lymphoblastic leukemia (ALL) at first relapse in children, adolescents and young adults.

The study demonstrated the superiority of blinatumomab for efficacy and tolerability, which is particularly encouraging given the challenges in getting relapsed ALL patients back into remission so they can undergo bone marrow transplant, Dr. Brodsky said.

Of 208 patients randomized, 73% vs. 45% in the blinatumomab vs. chemotherapy arms were able to get to transplant – and therefore to potential cure, he said.

“Of note, the blinatumomab arm was less toxic and there was marked improvement in disease-free and overall survival, so this is clearly going to become a new standard of care for relapsed and refractory ALL,” he added.

[email protected]

Chimeric antigen receptor (CAR) T-cell therapies have garnered a great deal of attention given their “incredible efficacy” in treating B-cell malignancies, and new findings are taking aim at the drawbacks of therapy, such as the time, expense, and toxicity involved, according to Robert A. Brodsky, MD.

One example, from a study slated for presentation during a plenary session at the upcoming annual meeting of the American Society of Hematology involves the investigational T-cell bispecific antibody mosunetuzumab, which targets both CD20 on the surface of malignant B cells, and CD3 on cytotoxic T cells, engaging the T cells and directing their cytotoxicity against B cells.

In a study (Abstract 6) of 218 non-Hodgkin lymphoma patients, including 23 who had already received CAR T-cell therapy and had relapsed or were refractory to the treatment, 64% responded, 42% had a complete response, and the median duration of response is now out to 9 months, Dr. Brodsky, ASH secretary and director of the division of hematology at Johns Hopkins University, Baltimore, said during a premeeting press conference.

“It’s basically an antibody using the patient’s own T cell to do what a CAR-T cell would do – [a] very exciting study and large study,” he said. “It is an off-the-shelf product, it completely gets around the problem of the time to generate the CAR T-cell product, and because it’s going to be much simpler and faster to produce, it’s likely going to be much cheaper than CAR T cells.”

The preliminary results also suggest it is less toxic than CAR T-cell therapy, he added.

Two other CAR T-cell therapy–related studies highlighted during the press conference address its use for multiple myeloma. One, the phase 1b/2 CARTITUDE study (Abstract 577) uses CAR T cells against the B-cell maturation antigen (BCMA) in the relapsed/refractory setting.

Of 25 patients treated with chemotherapy followed by CAR T-cell infusion and followed for a median of 3 months, 91% responded, two achieved a complete remission, and “many other responses were very deep responses,” Dr. Brodsky said, noting that the second featured multiple myeloma trial (Abstract 930) looked at bispecific CAR T-cell therapy targeting BCMA and CD38 in an effort to reduce resistance to the therapy.

“Again, very interesting preliminary results,” he said, noting that of 16 patients followed for a median of 36 weeks, 87.5% responded, the treatment was well tolerated, and progression-free survival at 9 months was 75%.

In addition to the “key theme” of overcoming CAR T-cell therapy obstacles, three other themes have emerged from among the thousands of abstracts submitted for presentation at ASH. These, as presented during the press conference, include new venous thromboembolism (VTE) therapies and approaches to research; inclusive medicine, with abstracts focused on age- and race-related issues in clinical trials; and new advances in the treatment of sickle cell disease. All of these have potentially practice-changing implications, as do the six late-breaking abstracts selected from 93 abstracts submitted for consideration for oral presentation at ASH, Dr. Brodsky said.

One of the “truly practice-changing” late-breakers is a randomized phase 3 trial (Abstract LBA-1) comparing the bispecific antibody blinatumomab to chemotherapy for post-re-induction therapy in high- and intermediate-risk acute lymphoblastic leukemia (ALL) at first relapse in children, adolescents and young adults.

The study demonstrated the superiority of blinatumomab for efficacy and tolerability, which is particularly encouraging given the challenges in getting relapsed ALL patients back into remission so they can undergo bone marrow transplant, Dr. Brodsky said.

Of 208 patients randomized, 73% vs. 45% in the blinatumomab vs. chemotherapy arms were able to get to transplant – and therefore to potential cure, he said.

“Of note, the blinatumomab arm was less toxic and there was marked improvement in disease-free and overall survival, so this is clearly going to become a new standard of care for relapsed and refractory ALL,” he added.

[email protected]

Chimeric antigen receptor (CAR) T-cell therapies have garnered a great deal of attention given their “incredible efficacy” in treating B-cell malignancies, and new findings are taking aim at the drawbacks of therapy, such as the time, expense, and toxicity involved, according to Robert A. Brodsky, MD.

One example, from a study slated for presentation during a plenary session at the upcoming annual meeting of the American Society of Hematology involves the investigational T-cell bispecific antibody mosunetuzumab, which targets both CD20 on the surface of malignant B cells, and CD3 on cytotoxic T cells, engaging the T cells and directing their cytotoxicity against B cells.

In a study (Abstract 6) of 218 non-Hodgkin lymphoma patients, including 23 who had already received CAR T-cell therapy and had relapsed or were refractory to the treatment, 64% responded, 42% had a complete response, and the median duration of response is now out to 9 months, Dr. Brodsky, ASH secretary and director of the division of hematology at Johns Hopkins University, Baltimore, said during a premeeting press conference.

“It’s basically an antibody using the patient’s own T cell to do what a CAR-T cell would do – [a] very exciting study and large study,” he said. “It is an off-the-shelf product, it completely gets around the problem of the time to generate the CAR T-cell product, and because it’s going to be much simpler and faster to produce, it’s likely going to be much cheaper than CAR T cells.”

The preliminary results also suggest it is less toxic than CAR T-cell therapy, he added.

Two other CAR T-cell therapy–related studies highlighted during the press conference address its use for multiple myeloma. One, the phase 1b/2 CARTITUDE study (Abstract 577) uses CAR T cells against the B-cell maturation antigen (BCMA) in the relapsed/refractory setting.

Of 25 patients treated with chemotherapy followed by CAR T-cell infusion and followed for a median of 3 months, 91% responded, two achieved a complete remission, and “many other responses were very deep responses,” Dr. Brodsky said, noting that the second featured multiple myeloma trial (Abstract 930) looked at bispecific CAR T-cell therapy targeting BCMA and CD38 in an effort to reduce resistance to the therapy.

“Again, very interesting preliminary results,” he said, noting that of 16 patients followed for a median of 36 weeks, 87.5% responded, the treatment was well tolerated, and progression-free survival at 9 months was 75%.

In addition to the “key theme” of overcoming CAR T-cell therapy obstacles, three other themes have emerged from among the thousands of abstracts submitted for presentation at ASH. These, as presented during the press conference, include new venous thromboembolism (VTE) therapies and approaches to research; inclusive medicine, with abstracts focused on age- and race-related issues in clinical trials; and new advances in the treatment of sickle cell disease. All of these have potentially practice-changing implications, as do the six late-breaking abstracts selected from 93 abstracts submitted for consideration for oral presentation at ASH, Dr. Brodsky said.

One of the “truly practice-changing” late-breakers is a randomized phase 3 trial (Abstract LBA-1) comparing the bispecific antibody blinatumomab to chemotherapy for post-re-induction therapy in high- and intermediate-risk acute lymphoblastic leukemia (ALL) at first relapse in children, adolescents and young adults.

The study demonstrated the superiority of blinatumomab for efficacy and tolerability, which is particularly encouraging given the challenges in getting relapsed ALL patients back into remission so they can undergo bone marrow transplant, Dr. Brodsky said.

Of 208 patients randomized, 73% vs. 45% in the blinatumomab vs. chemotherapy arms were able to get to transplant – and therefore to potential cure, he said.

“Of note, the blinatumomab arm was less toxic and there was marked improvement in disease-free and overall survival, so this is clearly going to become a new standard of care for relapsed and refractory ALL,” he added.

[email protected]

NATIONAL HARBOR, MD. – The combination of bempegaldesleukin and nivolumab produced durable responses in a phase 1/2 trial of patients with previously untreated metastatic melanoma.

Jennifer Smith/MDedge News

The overall response rate was 53%, and most responders were still in response at a median follow-up of about 19 months. The median progression-free survival was not reached, and the combination was considered well tolerated.

Adi Diab, MD, of the University of Texas MD Anderson Cancer Center, Houston, presented these results from the PIVOT-02 study at the annual meeting of the Society for Immunotherapy of Cancer.

Dr. Diab explained that bempegaldesleukin (bempeg) is a CD122-preferential interleukin-2 pathway agonist, and earlier results from the PIVOT-02 trial showed that adding bempeg to nivolumab can convert baseline tumors from programmed death–ligand 1 (PD-L1) negative to PD-L1 positive (SITC 2018, Abstract O4).

Dr. Diab presented updated results from PIVOT-02 (NCT02983045) in 41 patients with metastatic melanoma who received bempeg plus nivolumab as first-line treatment. The patients had a median age of 63 years (range, 22-80 years) at baseline, and 58.5% were male. Most patients (58.5%) were PD-L1 positive, although PD-L1 status was unknown in 7.3% of patients.

Patients received bempeg at 0.006 mg/kg and nivolumab at 360 mg every 3 weeks. They received a median of nine cycles (range, 1-34), and the median follow-up was 18.6 months.

Efficacy

In the 38 patients who were evaluable for efficacy, the overall response rate was 53% (n = 20), and the complete response rate was 34% (n = 13). The median time to response was 2.0 months, and the median time to complete response was 7.9 months.

Dr. Diab noted that responses were seen regardless of PD-L1 expression at baseline. The response rate was 39% among PD-L1-negative patients, 64% among PD-L1-positive patients, and 33% among patients whose PD-L1 status was unknown.

Dr. Diab also pointed out that responses were durable and deepened over time. The median duration of response was not reached, and 17 of the 20 responders had ongoing responses at last follow-up. The median progression-free survival has not been reached.

Safety

“This combination is safe and tolerable, there’s no overlapping immune-related adverse events, and the most common side effects are grade 1/2 flu-like symptoms,” Dr. Diab said.

The most common grade 1/2 treatment-related adverse events (AEs) were flu-like symptoms (80.5%), rash (70.7%), fatigue (65.9%), pruritus (48.8%), nausea (46.3%), arthralgia (43.9%), decreased appetite (36.6%), and myalgia (36.6%).

Dr. Diab noted that cytokine-related AEs (flu-like symptoms, rash, and pruritus) were easily managed with NSAIDs; decreased with subsequent cycles of treatment; and did not necessitate dose delays, reductions, or discontinuations.

Grade 3/4 treatment-related AEs included two cases of acute kidney injury, two cases of atrial fibrillation, one case of dizziness, one case of dyspnea, one case of hypoxia, one case of hyperglycemia, and one case of hypernatremia.

Five patients discontinued treatment because of related AEs, including cerebrovascular accident, peripheral edema, blood creatinine increase, malaise, and pharyngitis. There were no treatment-related deaths.

Dr. Diab said these results were used to support the recent breakthrough therapy designation granted to bempeg in combination with nivolumab. The results have also prompted a phase 3 trial in which researchers are comparing the combination with nivolumab alone (NCT03635983).

The phase 1/2 trial is sponsored by Nektar Therapeutics in collaboration with Bristol-Myers Squibb. Dr. Diab reported relationships with Nektar, Celgene, CureVac, Idera, and Pfizer.

SOURCE: Diab A et al. SITC 2019, Abstract O35.

NATIONAL HARBOR, MD. – The combination of bempegaldesleukin and nivolumab produced durable responses in a phase 1/2 trial of patients with previously untreated metastatic melanoma.

Jennifer Smith/MDedge News

The overall response rate was 53%, and most responders were still in response at a median follow-up of about 19 months. The median progression-free survival was not reached, and the combination was considered well tolerated.

Adi Diab, MD, of the University of Texas MD Anderson Cancer Center, Houston, presented these results from the PIVOT-02 study at the annual meeting of the Society for Immunotherapy of Cancer.

Dr. Diab explained that bempegaldesleukin (bempeg) is a CD122-preferential interleukin-2 pathway agonist, and earlier results from the PIVOT-02 trial showed that adding bempeg to nivolumab can convert baseline tumors from programmed death–ligand 1 (PD-L1) negative to PD-L1 positive (SITC 2018, Abstract O4).

Dr. Diab presented updated results from PIVOT-02 (NCT02983045) in 41 patients with metastatic melanoma who received bempeg plus nivolumab as first-line treatment. The patients had a median age of 63 years (range, 22-80 years) at baseline, and 58.5% were male. Most patients (58.5%) were PD-L1 positive, although PD-L1 status was unknown in 7.3% of patients.

Patients received bempeg at 0.006 mg/kg and nivolumab at 360 mg every 3 weeks. They received a median of nine cycles (range, 1-34), and the median follow-up was 18.6 months.

Efficacy

In the 38 patients who were evaluable for efficacy, the overall response rate was 53% (n = 20), and the complete response rate was 34% (n = 13). The median time to response was 2.0 months, and the median time to complete response was 7.9 months.

Dr. Diab noted that responses were seen regardless of PD-L1 expression at baseline. The response rate was 39% among PD-L1-negative patients, 64% among PD-L1-positive patients, and 33% among patients whose PD-L1 status was unknown.

Dr. Diab also pointed out that responses were durable and deepened over time. The median duration of response was not reached, and 17 of the 20 responders had ongoing responses at last follow-up. The median progression-free survival has not been reached.

Safety

“This combination is safe and tolerable, there’s no overlapping immune-related adverse events, and the most common side effects are grade 1/2 flu-like symptoms,” Dr. Diab said.

The most common grade 1/2 treatment-related adverse events (AEs) were flu-like symptoms (80.5%), rash (70.7%), fatigue (65.9%), pruritus (48.8%), nausea (46.3%), arthralgia (43.9%), decreased appetite (36.6%), and myalgia (36.6%).

Dr. Diab noted that cytokine-related AEs (flu-like symptoms, rash, and pruritus) were easily managed with NSAIDs; decreased with subsequent cycles of treatment; and did not necessitate dose delays, reductions, or discontinuations.

Grade 3/4 treatment-related AEs included two cases of acute kidney injury, two cases of atrial fibrillation, one case of dizziness, one case of dyspnea, one case of hypoxia, one case of hyperglycemia, and one case of hypernatremia.

Five patients discontinued treatment because of related AEs, including cerebrovascular accident, peripheral edema, blood creatinine increase, malaise, and pharyngitis. There were no treatment-related deaths.

Dr. Diab said these results were used to support the recent breakthrough therapy designation granted to bempeg in combination with nivolumab. The results have also prompted a phase 3 trial in which researchers are comparing the combination with nivolumab alone (NCT03635983).

The phase 1/2 trial is sponsored by Nektar Therapeutics in collaboration with Bristol-Myers Squibb. Dr. Diab reported relationships with Nektar, Celgene, CureVac, Idera, and Pfizer.

SOURCE: Diab A et al. SITC 2019, Abstract O35.

NATIONAL HARBOR, MD. – The combination of bempegaldesleukin and nivolumab produced durable responses in a phase 1/2 trial of patients with previously untreated metastatic melanoma.

Jennifer Smith/MDedge News

The overall response rate was 53%, and most responders were still in response at a median follow-up of about 19 months. The median progression-free survival was not reached, and the combination was considered well tolerated.

Adi Diab, MD, of the University of Texas MD Anderson Cancer Center, Houston, presented these results from the PIVOT-02 study at the annual meeting of the Society for Immunotherapy of Cancer.

Dr. Diab explained that bempegaldesleukin (bempeg) is a CD122-preferential interleukin-2 pathway agonist, and earlier results from the PIVOT-02 trial showed that adding bempeg to nivolumab can convert baseline tumors from programmed death–ligand 1 (PD-L1) negative to PD-L1 positive (SITC 2018, Abstract O4).

Dr. Diab presented updated results from PIVOT-02 (NCT02983045) in 41 patients with metastatic melanoma who received bempeg plus nivolumab as first-line treatment. The patients had a median age of 63 years (range, 22-80 years) at baseline, and 58.5% were male. Most patients (58.5%) were PD-L1 positive, although PD-L1 status was unknown in 7.3% of patients.

Patients received bempeg at 0.006 mg/kg and nivolumab at 360 mg every 3 weeks. They received a median of nine cycles (range, 1-34), and the median follow-up was 18.6 months.

Efficacy

In the 38 patients who were evaluable for efficacy, the overall response rate was 53% (n = 20), and the complete response rate was 34% (n = 13). The median time to response was 2.0 months, and the median time to complete response was 7.9 months.

Dr. Diab noted that responses were seen regardless of PD-L1 expression at baseline. The response rate was 39% among PD-L1-negative patients, 64% among PD-L1-positive patients, and 33% among patients whose PD-L1 status was unknown.

Dr. Diab also pointed out that responses were durable and deepened over time. The median duration of response was not reached, and 17 of the 20 responders had ongoing responses at last follow-up. The median progression-free survival has not been reached.

Safety

“This combination is safe and tolerable, there’s no overlapping immune-related adverse events, and the most common side effects are grade 1/2 flu-like symptoms,” Dr. Diab said.

The most common grade 1/2 treatment-related adverse events (AEs) were flu-like symptoms (80.5%), rash (70.7%), fatigue (65.9%), pruritus (48.8%), nausea (46.3%), arthralgia (43.9%), decreased appetite (36.6%), and myalgia (36.6%).

Dr. Diab noted that cytokine-related AEs (flu-like symptoms, rash, and pruritus) were easily managed with NSAIDs; decreased with subsequent cycles of treatment; and did not necessitate dose delays, reductions, or discontinuations.

Grade 3/4 treatment-related AEs included two cases of acute kidney injury, two cases of atrial fibrillation, one case of dizziness, one case of dyspnea, one case of hypoxia, one case of hyperglycemia, and one case of hypernatremia.

Five patients discontinued treatment because of related AEs, including cerebrovascular accident, peripheral edema, blood creatinine increase, malaise, and pharyngitis. There were no treatment-related deaths.

Dr. Diab said these results were used to support the recent breakthrough therapy designation granted to bempeg in combination with nivolumab. The results have also prompted a phase 3 trial in which researchers are comparing the combination with nivolumab alone (NCT03635983).

The phase 1/2 trial is sponsored by Nektar Therapeutics in collaboration with Bristol-Myers Squibb. Dr. Diab reported relationships with Nektar, Celgene, CureVac, Idera, and Pfizer.

SOURCE: Diab A et al. SITC 2019, Abstract O35.

The combination of atezolizumab plus bevacizumab may offer some benefit to patients with advanced renal cell carcinoma, especially those who are positive for programmed death-ligand 1 (PD-L1), investigators report.

The overall response rate (ORR) among such patients was 60%, compared with 19% in PD-L1–negative patients, Bradley A. McGregor, MD, clinical director for the Lank Center of Genitourinary Oncology at Dana-Farber Cancer Institute in Boston, and colleagues reported in the Journal of Clinical Oncology.

The data were presented last summer at the American Society of Clinical Oncology Annual Meeting in Chicago.

The phase 2 study comprised 60 patients, 42 of whom had variant histology RCC, and 18 of whom had clear cell RCC (ccRCC ) with at least 20% sarcomatoid differentiation. All patients had advanced renal cell carcinoma of various histologies, including papillary (12), chromophobe (10), unclassified (9), TFE3 translocation (5), collecting duct (5), and medullary (1). Most (65%) had not received prior systemic therapy.

They all received infusions of atezolizumab 1,200 mg plus bevacizumab 15 mg/kg every 3 weeks. No dose modifications were allowed. Dose delays were allowed, and patients could also drop one agent and continue with the other. Treatment continued until disease progression, toxicity, or intolerable side effects.

The median number of cycles was 9.5, although the range was wide (1-42). At analysis, 15 were still on the treatment, but 45 had dropped out. Reasons were disease progression (34), death (1), toxicity (5), or unspecified (8). Six patients delayed bevacizumab doses, half because of adverse events.

After a median follow-up of 13 months, the ORR was 33%. Those with ccRCC with sarcomatoid differentiation responded best to the combination (ORR, 50%). Those with variant-histology RCC responded less robustly (ORR, 26%).

ORR varied by baseline risk category, being 33% in favorable-, 45% in intermediate-, and 11% in poor-risk patients. Median time to response was 2.7 months, median response duration was 8.9 months, and median progression-free survival was 8.3 months.

PD-L1 status was determined in 36 patients; 15 were positive. Among the positive patents, ORR was 60%, compared with 19% in PD-L1 negative patients. Response rates varied with tumor characteristics. Among patients with ccRCC with sarcomatoid differentiation, the ORR was 50% in PD-L1–positive patients and 29% in negative patients. In patients with variant histology RCC, the ORR was also better in PD-L1 positive patients (67% vs. 14%).

The most common treatment-related side effects were fatigue (35%), proteinuria (35%), musculoskeletal pain (33%), diarrhea (22%), rash (20%), hypertension (18%), pruritus (18%), thyroid dysfunction (17%), hepatitis (15%), fever (13%), and mucositis (12%). Thirty-four patients developed at least one grade 3 adverse event; there were no grade 4 or 5 toxicities. One patient died, presumably because of disease progression.

Quality of life scores were largely stable during treatment.

“The combination demonstrated responses across several subtypes of RCC, including collecting duct and medullary carcinoma, histologies that are often treated with cytotoxic chemotherapy,” the authors said. “This is notable given the generally poor prognosis and low response rate associated with variant histology RCC in trials to date.”

The study also suggests the PD-L1 status might be “intriguing as a biomarker for response to atezolizumab and bevacizumab in variant histology RCC. We plan to conduct additional correlative work, including genomic profiling and assessment of the immune microenvironment, to better elucidate markers of response and resistance,” the authors wrote.

SOURCE: McGregor BA et al. J Clin Oncol. 2019 Nov 13. doi: 10.1200/JCO.19.01882.

The combination of atezolizumab plus bevacizumab may offer some benefit to patients with advanced renal cell carcinoma, especially those who are positive for programmed death-ligand 1 (PD-L1), investigators report.

The overall response rate (ORR) among such patients was 60%, compared with 19% in PD-L1–negative patients, Bradley A. McGregor, MD, clinical director for the Lank Center of Genitourinary Oncology at Dana-Farber Cancer Institute in Boston, and colleagues reported in the Journal of Clinical Oncology.

The data were presented last summer at the American Society of Clinical Oncology Annual Meeting in Chicago.

The phase 2 study comprised 60 patients, 42 of whom had variant histology RCC, and 18 of whom had clear cell RCC (ccRCC ) with at least 20% sarcomatoid differentiation. All patients had advanced renal cell carcinoma of various histologies, including papillary (12), chromophobe (10), unclassified (9), TFE3 translocation (5), collecting duct (5), and medullary (1). Most (65%) had not received prior systemic therapy.

They all received infusions of atezolizumab 1,200 mg plus bevacizumab 15 mg/kg every 3 weeks. No dose modifications were allowed. Dose delays were allowed, and patients could also drop one agent and continue with the other. Treatment continued until disease progression, toxicity, or intolerable side effects.

The median number of cycles was 9.5, although the range was wide (1-42). At analysis, 15 were still on the treatment, but 45 had dropped out. Reasons were disease progression (34), death (1), toxicity (5), or unspecified (8). Six patients delayed bevacizumab doses, half because of adverse events.

After a median follow-up of 13 months, the ORR was 33%. Those with ccRCC with sarcomatoid differentiation responded best to the combination (ORR, 50%). Those with variant-histology RCC responded less robustly (ORR, 26%).

ORR varied by baseline risk category, being 33% in favorable-, 45% in intermediate-, and 11% in poor-risk patients. Median time to response was 2.7 months, median response duration was 8.9 months, and median progression-free survival was 8.3 months.

PD-L1 status was determined in 36 patients; 15 were positive. Among the positive patents, ORR was 60%, compared with 19% in PD-L1 negative patients. Response rates varied with tumor characteristics. Among patients with ccRCC with sarcomatoid differentiation, the ORR was 50% in PD-L1–positive patients and 29% in negative patients. In patients with variant histology RCC, the ORR was also better in PD-L1 positive patients (67% vs. 14%).

The most common treatment-related side effects were fatigue (35%), proteinuria (35%), musculoskeletal pain (33%), diarrhea (22%), rash (20%), hypertension (18%), pruritus (18%), thyroid dysfunction (17%), hepatitis (15%), fever (13%), and mucositis (12%). Thirty-four patients developed at least one grade 3 adverse event; there were no grade 4 or 5 toxicities. One patient died, presumably because of disease progression.

Quality of life scores were largely stable during treatment.

“The combination demonstrated responses across several subtypes of RCC, including collecting duct and medullary carcinoma, histologies that are often treated with cytotoxic chemotherapy,” the authors said. “This is notable given the generally poor prognosis and low response rate associated with variant histology RCC in trials to date.”

The study also suggests the PD-L1 status might be “intriguing as a biomarker for response to atezolizumab and bevacizumab in variant histology RCC. We plan to conduct additional correlative work, including genomic profiling and assessment of the immune microenvironment, to better elucidate markers of response and resistance,” the authors wrote.

SOURCE: McGregor BA et al. J Clin Oncol. 2019 Nov 13. doi: 10.1200/JCO.19.01882.

The combination of atezolizumab plus bevacizumab may offer some benefit to patients with advanced renal cell carcinoma, especially those who are positive for programmed death-ligand 1 (PD-L1), investigators report.

The overall response rate (ORR) among such patients was 60%, compared with 19% in PD-L1–negative patients, Bradley A. McGregor, MD, clinical director for the Lank Center of Genitourinary Oncology at Dana-Farber Cancer Institute in Boston, and colleagues reported in the Journal of Clinical Oncology.

The data were presented last summer at the American Society of Clinical Oncology Annual Meeting in Chicago.

The phase 2 study comprised 60 patients, 42 of whom had variant histology RCC, and 18 of whom had clear cell RCC (ccRCC ) with at least 20% sarcomatoid differentiation. All patients had advanced renal cell carcinoma of various histologies, including papillary (12), chromophobe (10), unclassified (9), TFE3 translocation (5), collecting duct (5), and medullary (1). Most (65%) had not received prior systemic therapy.

They all received infusions of atezolizumab 1,200 mg plus bevacizumab 15 mg/kg every 3 weeks. No dose modifications were allowed. Dose delays were allowed, and patients could also drop one agent and continue with the other. Treatment continued until disease progression, toxicity, or intolerable side effects.

The median number of cycles was 9.5, although the range was wide (1-42). At analysis, 15 were still on the treatment, but 45 had dropped out. Reasons were disease progression (34), death (1), toxicity (5), or unspecified (8). Six patients delayed bevacizumab doses, half because of adverse events.

After a median follow-up of 13 months, the ORR was 33%. Those with ccRCC with sarcomatoid differentiation responded best to the combination (ORR, 50%). Those with variant-histology RCC responded less robustly (ORR, 26%).

ORR varied by baseline risk category, being 33% in favorable-, 45% in intermediate-, and 11% in poor-risk patients. Median time to response was 2.7 months, median response duration was 8.9 months, and median progression-free survival was 8.3 months.

PD-L1 status was determined in 36 patients; 15 were positive. Among the positive patents, ORR was 60%, compared with 19% in PD-L1 negative patients. Response rates varied with tumor characteristics. Among patients with ccRCC with sarcomatoid differentiation, the ORR was 50% in PD-L1–positive patients and 29% in negative patients. In patients with variant histology RCC, the ORR was also better in PD-L1 positive patients (67% vs. 14%).

The most common treatment-related side effects were fatigue (35%), proteinuria (35%), musculoskeletal pain (33%), diarrhea (22%), rash (20%), hypertension (18%), pruritus (18%), thyroid dysfunction (17%), hepatitis (15%), fever (13%), and mucositis (12%). Thirty-four patients developed at least one grade 3 adverse event; there were no grade 4 or 5 toxicities. One patient died, presumably because of disease progression.

Quality of life scores were largely stable during treatment.

“The combination demonstrated responses across several subtypes of RCC, including collecting duct and medullary carcinoma, histologies that are often treated with cytotoxic chemotherapy,” the authors said. “This is notable given the generally poor prognosis and low response rate associated with variant histology RCC in trials to date.”

The study also suggests the PD-L1 status might be “intriguing as a biomarker for response to atezolizumab and bevacizumab in variant histology RCC. We plan to conduct additional correlative work, including genomic profiling and assessment of the immune microenvironment, to better elucidate markers of response and resistance,” the authors wrote.

SOURCE: McGregor BA et al. J Clin Oncol. 2019 Nov 13. doi: 10.1200/JCO.19.01882.

NATIONAL HARBOR, MD. – Trial results suggest a personalized vaccination approach is feasible and safe, and the vaccine can produce clinical responses in patients with non–small cell lung cancer (NSCLC).

Jennifer Smith/MDedge News

The neoantigen vaccine produced only grade 1 adverse events, yielded responses in patients with epidermal growth factor receptor (EGFR) mutations, and proved particularly effective in patients who were also receiving an EGFR inhibitor.

“EGFR inhibitors seemed to reduce tumor immunosuppression barriers and may enhance antitumor immune responses before and during immunization, suggesting there may be a potential synergy of EGFR with immunotherapies,” Gregory A. Lizee, PhD, of University of Texas MD Anderson Cancer Center, Houston, said at the annual meeting of the Society for Immunotherapy of Cancer.

The research began with an elderly patient who had heavily pretreated NSCLC (Oncoimmunology. 2016;5[12]:e1238539). Dr. Lizee and colleagues used tumor mutational profiling and human leukocyte antigen (HLA) typing to develop a personalized peptide vaccine for the patient. He received the vaccine along with topical imiquimod and had multiple lung tumor nodules regress. However, the patient also had liver metastasis that remained refractory to treatment, and he ultimately died.

To investigate this treatment approach in a larger group, Dr. Lizee and colleagues began a phase 1b trial of patients with advanced NSCLC (ChiCTR-IIR-16009867). As with the prior patient, the researchers designed personalized peptide vaccines for the trial subjects based on mutational profiling of 508 cancer-associated genes and high-resolution HLA typing. The peptides were selected based on nonsynonymous somatic tumor–associated mutations with variant allele frequency greater than 0.04 and the highest predicted neoantigen peptide binding to each patient’s HLA class I and II molecules. The vaccines targeted up to eight independent somatic mutations (mean, 3.75 mutations).

In all, 31 patients provided lung tumor biopsies and peripheral blood for mutational and HLA analyses. The researchers designed 27 personalized neoantigen vaccines, and 24 patients were ultimately vaccinated. This translates to a vaccination rate of 77%, which suggests this treatment approach is feasible, Dr. Lizee said.

Of the 24 vaccinated patients, 18 had adenocarcinoma, and 6 had squamous cell carcinoma. All patients had received multiple prior therapies, including surgery, chemotherapy, radiation, and EGFR inhibitors.

Each patient was vaccinated with a personalized mixture of short and long neoantigen peptides (mean, 9.4 peptides) dissolved in isotonic saline. Patients received at least 12 weekly immunizations and had topical imiquimod applied over the injection site for costimulation through toll-like receptor 7. The 16 patients with EGFR mutations were given the option of continuing on an EGFR inhibitor, and 9 patients elected to do so.
 

Results

Dr. Lizee said this treatment approach was “very safe,” with only grade 1 treatment-related adverse events. The events were fatigue (n = 2), rash (n = 1), and fever (n = 1).

Seven patients achieved a response after vaccination, and one patient achieved a complete response. All seven responders had EGFR mutations, and four of them were receiving an EGFR inhibitor.

The patients on an EGFR inhibitor had significantly better overall survival than that of EGFR-mutated patients who had stopped taking an EGFR inhibitor – 13.8 months and 7.6 months, respectively (P = .038).

Immune profiling revealed that neoantigen-specific T-cell reactivity was associated with clinical responses. The researchers observed EGFR neoantigen-specific T-cell responses in five responders. In three responders, the strongest response was against a peptide encompassing the L858R driver mutation.

The researchers also found evidence of synergy between EGFR inhibitor therapy and the peptide vaccine. EGFR inhibition caused immunomodulatory pathways in EGFR-mutated cancer cells to favor immune-cell infiltration and HLA-mediated antigen presentation.

“Our mechanistic working model is that, in the circulation, the personalized vaccine increased the T-cell frequency,” Dr. Lizee said. “The EGFR inhibitor increased chemokines and antigen presentation at the tumor site, which then attracted those T cells to migrate to the tumor. Then, recognition of the antigen caused interferon gamma [to increase], which caused, potentially, a feed-forward loop by increasing chemokines and antigen presentation further.”

This research is sponsored by Tianjin Beichen Hospital and funded by Tianjin HengJia Biotechnology Development Co. Ltd. Dr. Lizee disclosed a consulting relationship with Tianjin HengJia Biotechnology Development Co. Ltd.

SOURCE: Lizee G et al. SITC 2019. Abstract O18.

NATIONAL HARBOR, MD. – Trial results suggest a personalized vaccination approach is feasible and safe, and the vaccine can produce clinical responses in patients with non–small cell lung cancer (NSCLC).

Jennifer Smith/MDedge News

The neoantigen vaccine produced only grade 1 adverse events, yielded responses in patients with epidermal growth factor receptor (EGFR) mutations, and proved particularly effective in patients who were also receiving an EGFR inhibitor.

“EGFR inhibitors seemed to reduce tumor immunosuppression barriers and may enhance antitumor immune responses before and during immunization, suggesting there may be a potential synergy of EGFR with immunotherapies,” Gregory A. Lizee, PhD, of University of Texas MD Anderson Cancer Center, Houston, said at the annual meeting of the Society for Immunotherapy of Cancer.

The research began with an elderly patient who had heavily pretreated NSCLC (Oncoimmunology. 2016;5[12]:e1238539). Dr. Lizee and colleagues used tumor mutational profiling and human leukocyte antigen (HLA) typing to develop a personalized peptide vaccine for the patient. He received the vaccine along with topical imiquimod and had multiple lung tumor nodules regress. However, the patient also had liver metastasis that remained refractory to treatment, and he ultimately died.

To investigate this treatment approach in a larger group, Dr. Lizee and colleagues began a phase 1b trial of patients with advanced NSCLC (ChiCTR-IIR-16009867). As with the prior patient, the researchers designed personalized peptide vaccines for the trial subjects based on mutational profiling of 508 cancer-associated genes and high-resolution HLA typing. The peptides were selected based on nonsynonymous somatic tumor–associated mutations with variant allele frequency greater than 0.04 and the highest predicted neoantigen peptide binding to each patient’s HLA class I and II molecules. The vaccines targeted up to eight independent somatic mutations (mean, 3.75 mutations).

In all, 31 patients provided lung tumor biopsies and peripheral blood for mutational and HLA analyses. The researchers designed 27 personalized neoantigen vaccines, and 24 patients were ultimately vaccinated. This translates to a vaccination rate of 77%, which suggests this treatment approach is feasible, Dr. Lizee said.

Of the 24 vaccinated patients, 18 had adenocarcinoma, and 6 had squamous cell carcinoma. All patients had received multiple prior therapies, including surgery, chemotherapy, radiation, and EGFR inhibitors.

Each patient was vaccinated with a personalized mixture of short and long neoantigen peptides (mean, 9.4 peptides) dissolved in isotonic saline. Patients received at least 12 weekly immunizations and had topical imiquimod applied over the injection site for costimulation through toll-like receptor 7. The 16 patients with EGFR mutations were given the option of continuing on an EGFR inhibitor, and 9 patients elected to do so.
 

Results

Dr. Lizee said this treatment approach was “very safe,” with only grade 1 treatment-related adverse events. The events were fatigue (n = 2), rash (n = 1), and fever (n = 1).

Seven patients achieved a response after vaccination, and one patient achieved a complete response. All seven responders had EGFR mutations, and four of them were receiving an EGFR inhibitor.

The patients on an EGFR inhibitor had significantly better overall survival than that of EGFR-mutated patients who had stopped taking an EGFR inhibitor – 13.8 months and 7.6 months, respectively (P = .038).

Immune profiling revealed that neoantigen-specific T-cell reactivity was associated with clinical responses. The researchers observed EGFR neoantigen-specific T-cell responses in five responders. In three responders, the strongest response was against a peptide encompassing the L858R driver mutation.

The researchers also found evidence of synergy between EGFR inhibitor therapy and the peptide vaccine. EGFR inhibition caused immunomodulatory pathways in EGFR-mutated cancer cells to favor immune-cell infiltration and HLA-mediated antigen presentation.

“Our mechanistic working model is that, in the circulation, the personalized vaccine increased the T-cell frequency,” Dr. Lizee said. “The EGFR inhibitor increased chemokines and antigen presentation at the tumor site, which then attracted those T cells to migrate to the tumor. Then, recognition of the antigen caused interferon gamma [to increase], which caused, potentially, a feed-forward loop by increasing chemokines and antigen presentation further.”

This research is sponsored by Tianjin Beichen Hospital and funded by Tianjin HengJia Biotechnology Development Co. Ltd. Dr. Lizee disclosed a consulting relationship with Tianjin HengJia Biotechnology Development Co. Ltd.

SOURCE: Lizee G et al. SITC 2019. Abstract O18.

NATIONAL HARBOR, MD. – Trial results suggest a personalized vaccination approach is feasible and safe, and the vaccine can produce clinical responses in patients with non–small cell lung cancer (NSCLC).

Jennifer Smith/MDedge News

The neoantigen vaccine produced only grade 1 adverse events, yielded responses in patients with epidermal growth factor receptor (EGFR) mutations, and proved particularly effective in patients who were also receiving an EGFR inhibitor.

“EGFR inhibitors seemed to reduce tumor immunosuppression barriers and may enhance antitumor immune responses before and during immunization, suggesting there may be a potential synergy of EGFR with immunotherapies,” Gregory A. Lizee, PhD, of University of Texas MD Anderson Cancer Center, Houston, said at the annual meeting of the Society for Immunotherapy of Cancer.

The research began with an elderly patient who had heavily pretreated NSCLC (Oncoimmunology. 2016;5[12]:e1238539). Dr. Lizee and colleagues used tumor mutational profiling and human leukocyte antigen (HLA) typing to develop a personalized peptide vaccine for the patient. He received the vaccine along with topical imiquimod and had multiple lung tumor nodules regress. However, the patient also had liver metastasis that remained refractory to treatment, and he ultimately died.

To investigate this treatment approach in a larger group, Dr. Lizee and colleagues began a phase 1b trial of patients with advanced NSCLC (ChiCTR-IIR-16009867). As with the prior patient, the researchers designed personalized peptide vaccines for the trial subjects based on mutational profiling of 508 cancer-associated genes and high-resolution HLA typing. The peptides were selected based on nonsynonymous somatic tumor–associated mutations with variant allele frequency greater than 0.04 and the highest predicted neoantigen peptide binding to each patient’s HLA class I and II molecules. The vaccines targeted up to eight independent somatic mutations (mean, 3.75 mutations).

In all, 31 patients provided lung tumor biopsies and peripheral blood for mutational and HLA analyses. The researchers designed 27 personalized neoantigen vaccines, and 24 patients were ultimately vaccinated. This translates to a vaccination rate of 77%, which suggests this treatment approach is feasible, Dr. Lizee said.

Of the 24 vaccinated patients, 18 had adenocarcinoma, and 6 had squamous cell carcinoma. All patients had received multiple prior therapies, including surgery, chemotherapy, radiation, and EGFR inhibitors.

Each patient was vaccinated with a personalized mixture of short and long neoantigen peptides (mean, 9.4 peptides) dissolved in isotonic saline. Patients received at least 12 weekly immunizations and had topical imiquimod applied over the injection site for costimulation through toll-like receptor 7. The 16 patients with EGFR mutations were given the option of continuing on an EGFR inhibitor, and 9 patients elected to do so.
 

Results

Dr. Lizee said this treatment approach was “very safe,” with only grade 1 treatment-related adverse events. The events were fatigue (n = 2), rash (n = 1), and fever (n = 1).

Seven patients achieved a response after vaccination, and one patient achieved a complete response. All seven responders had EGFR mutations, and four of them were receiving an EGFR inhibitor.

The patients on an EGFR inhibitor had significantly better overall survival than that of EGFR-mutated patients who had stopped taking an EGFR inhibitor – 13.8 months and 7.6 months, respectively (P = .038).

Immune profiling revealed that neoantigen-specific T-cell reactivity was associated with clinical responses. The researchers observed EGFR neoantigen-specific T-cell responses in five responders. In three responders, the strongest response was against a peptide encompassing the L858R driver mutation.

The researchers also found evidence of synergy between EGFR inhibitor therapy and the peptide vaccine. EGFR inhibition caused immunomodulatory pathways in EGFR-mutated cancer cells to favor immune-cell infiltration and HLA-mediated antigen presentation.

“Our mechanistic working model is that, in the circulation, the personalized vaccine increased the T-cell frequency,” Dr. Lizee said. “The EGFR inhibitor increased chemokines and antigen presentation at the tumor site, which then attracted those T cells to migrate to the tumor. Then, recognition of the antigen caused interferon gamma [to increase], which caused, potentially, a feed-forward loop by increasing chemokines and antigen presentation further.”

This research is sponsored by Tianjin Beichen Hospital and funded by Tianjin HengJia Biotechnology Development Co. Ltd. Dr. Lizee disclosed a consulting relationship with Tianjin HengJia Biotechnology Development Co. Ltd.

SOURCE: Lizee G et al. SITC 2019. Abstract O18.

NATIONAL HARBOR, MD. – An immunochemotherapy regimen produced mixed results in a phase 2 trial of patients with previously untreated metastatic colorectal cancer.

The regimen – avelumab and cetuximab plus oxaliplatin, leucovorin, and 5-fluorouracil (mFOLFOX6) – failed to meet the primary endpoint for progression-free survival (PFS) but was associated with “promising” yet “preliminary” overall survival, according to Joseph Tintelnot, MD, of University Medical Center Hamburg-Eppendorf (Germany).

Dr. Tintelnot presented these results from the AVETUX trial (NCT03174405) at the annual meeting of the Society for Immunotherapy of Cancer.

The trial enrolled 43 patients with previously untreated, metastatic colorectal cancer, and 39 of them had wild-type RAS and BRAF mutations. Among those 39 patients, the median age was 62 years (range, 29-82 years), 13 patients were female, and 36 patients had left-sided tumors.

A total of 30 patients had liver metastasis, 12 had lung metastasis, and 18 had lymph node metastasis. Most patients (n = 36) had microsatellite stable tumors, 2 were microsatellite instability high, and 1 was microsatellite instability low.

Patients received IV cetuximab at 250 mg/m² over 60-90 minutes (day 1 and 8), with a first dose of 400 mg/m^2; mFOLFOX6 according to local standard – IV oxaliplatin at 85 mg/m² IV (day 1), IV leucovorin at 400 mg/m² IV (day 1), and IV bolus 5-fluorouracil at 400 mg/m² (day 1) and IV at 2,400 mg/m² (days 1-3); and IV avelumab at 10 mg/kg over 60-90 minutes (day 1 from cycle 2 onward).

The median number of treatment cycles was 8 (range, 1-34) for oxaliplatin, 13 (range, 1-35) for 5-fluorouracil, 12 (range, 1-35) for cetuximab, and 16 (range, 0-34) for avelumab. The median duration of cetuximab/avelumab treatment was 5.4 months (range, 0.7-18.4 months).

The study’s primary endpoint was 12-month PFS, and the researchers expected the PFS to rise from 40% to 57%. Unfortunately, the 12-month PFS was 40%, so the primary endpoint was not met.

However, the treatment produced a “very high” overall response rate at 81% (30/37), according to Dr. Tintelnot. A total of 4 patients achieved a complete response, 26 had a partial response, 4 had stable disease, and 3 progressed.

Dr. Tintelnot also noted a “promising” but “preliminary” overall survival rate – 84% at a median follow-up of 16.2 months. He said these results suggest PFS may not be the ideal endpoint for this combination.

Dr. Tintelnot said the combination was safe, with no unexpected toxicities. The most common grade 3-4 adverse events were infection of catheter, device, urinary tract, etc. (32%); abdominal pain, diarrhea, etc. (24%); skin reaction (21%); anemia, blood disorders, and hemolytic-uremic syndrome (18%); administration, infusion-related, and allergic reactions (16%); cognitive disturbance, meningism, syncope, and psychiatric disorders (16%); and peripheral sensory polyneuropathy and paresthesia (16%).

Dr. Tintelnot and colleagues also conducted translational research evaluating programmed death-ligand 1 (PD-L1) expression and serial circulating tumor DNA in patients on this trial.

The team found no clear correlation between PFS and T-cell diversification, tumor-infiltrating lymphocytes, or tumor proportion score. Dr. Tintelnot said this suggests classical predictive factors for PD-1/PD-L1 inhibitor treatment have a limited role with this combination.

The researchers did find that circulating tumor mutations might help predict early relapse with the regimen. The team identified 26 patients with mutations detectable in their blood. There was an immediate decline of circulating tumor mutations after treatment initiation, and reemergence of mutation clones was associated with progression.

Lastly, the researchers found that avelumab, cetuximab, and mFOLFOX6 suppressed the development of epidermal growth factor receptor–resistant subclones. There were no epidermal growth factor receptor mutations detected during follow-up.

This research was sponsored by AIO-Studien-gGmbH. Dr. Tintelnot disclosed no conflicts of interest.

SOURCE: Tintelnot J et al. SITC 2019, Abstract O16.
 

NATIONAL HARBOR, MD. – An immunochemotherapy regimen produced mixed results in a phase 2 trial of patients with previously untreated metastatic colorectal cancer.

The regimen – avelumab and cetuximab plus oxaliplatin, leucovorin, and 5-fluorouracil (mFOLFOX6) – failed to meet the primary endpoint for progression-free survival (PFS) but was associated with “promising” yet “preliminary” overall survival, according to Joseph Tintelnot, MD, of University Medical Center Hamburg-Eppendorf (Germany).

Dr. Tintelnot presented these results from the AVETUX trial (NCT03174405) at the annual meeting of the Society for Immunotherapy of Cancer.

The trial enrolled 43 patients with previously untreated, metastatic colorectal cancer, and 39 of them had wild-type RAS and BRAF mutations. Among those 39 patients, the median age was 62 years (range, 29-82 years), 13 patients were female, and 36 patients had left-sided tumors.

A total of 30 patients had liver metastasis, 12 had lung metastasis, and 18 had lymph node metastasis. Most patients (n = 36) had microsatellite stable tumors, 2 were microsatellite instability high, and 1 was microsatellite instability low.

Patients received IV cetuximab at 250 mg/m² over 60-90 minutes (day 1 and 8), with a first dose of 400 mg/m^2; mFOLFOX6 according to local standard – IV oxaliplatin at 85 mg/m² IV (day 1), IV leucovorin at 400 mg/m² IV (day 1), and IV bolus 5-fluorouracil at 400 mg/m² (day 1) and IV at 2,400 mg/m² (days 1-3); and IV avelumab at 10 mg/kg over 60-90 minutes (day 1 from cycle 2 onward).

The median number of treatment cycles was 8 (range, 1-34) for oxaliplatin, 13 (range, 1-35) for 5-fluorouracil, 12 (range, 1-35) for cetuximab, and 16 (range, 0-34) for avelumab. The median duration of cetuximab/avelumab treatment was 5.4 months (range, 0.7-18.4 months).

The study’s primary endpoint was 12-month PFS, and the researchers expected the PFS to rise from 40% to 57%. Unfortunately, the 12-month PFS was 40%, so the primary endpoint was not met.

However, the treatment produced a “very high” overall response rate at 81% (30/37), according to Dr. Tintelnot. A total of 4 patients achieved a complete response, 26 had a partial response, 4 had stable disease, and 3 progressed.

Dr. Tintelnot also noted a “promising” but “preliminary” overall survival rate – 84% at a median follow-up of 16.2 months. He said these results suggest PFS may not be the ideal endpoint for this combination.

Dr. Tintelnot said the combination was safe, with no unexpected toxicities. The most common grade 3-4 adverse events were infection of catheter, device, urinary tract, etc. (32%); abdominal pain, diarrhea, etc. (24%); skin reaction (21%); anemia, blood disorders, and hemolytic-uremic syndrome (18%); administration, infusion-related, and allergic reactions (16%); cognitive disturbance, meningism, syncope, and psychiatric disorders (16%); and peripheral sensory polyneuropathy and paresthesia (16%).

Dr. Tintelnot and colleagues also conducted translational research evaluating programmed death-ligand 1 (PD-L1) expression and serial circulating tumor DNA in patients on this trial.

The team found no clear correlation between PFS and T-cell diversification, tumor-infiltrating lymphocytes, or tumor proportion score. Dr. Tintelnot said this suggests classical predictive factors for PD-1/PD-L1 inhibitor treatment have a limited role with this combination.

The researchers did find that circulating tumor mutations might help predict early relapse with the regimen. The team identified 26 patients with mutations detectable in their blood. There was an immediate decline of circulating tumor mutations after treatment initiation, and reemergence of mutation clones was associated with progression.

Lastly, the researchers found that avelumab, cetuximab, and mFOLFOX6 suppressed the development of epidermal growth factor receptor–resistant subclones. There were no epidermal growth factor receptor mutations detected during follow-up.

This research was sponsored by AIO-Studien-gGmbH. Dr. Tintelnot disclosed no conflicts of interest.

SOURCE: Tintelnot J et al. SITC 2019, Abstract O16.
 

NATIONAL HARBOR, MD. – An immunochemotherapy regimen produced mixed results in a phase 2 trial of patients with previously untreated metastatic colorectal cancer.

The regimen – avelumab and cetuximab plus oxaliplatin, leucovorin, and 5-fluorouracil (mFOLFOX6) – failed to meet the primary endpoint for progression-free survival (PFS) but was associated with “promising” yet “preliminary” overall survival, according to Joseph Tintelnot, MD, of University Medical Center Hamburg-Eppendorf (Germany).

Dr. Tintelnot presented these results from the AVETUX trial (NCT03174405) at the annual meeting of the Society for Immunotherapy of Cancer.

The trial enrolled 43 patients with previously untreated, metastatic colorectal cancer, and 39 of them had wild-type RAS and BRAF mutations. Among those 39 patients, the median age was 62 years (range, 29-82 years), 13 patients were female, and 36 patients had left-sided tumors.

A total of 30 patients had liver metastasis, 12 had lung metastasis, and 18 had lymph node metastasis. Most patients (n = 36) had microsatellite stable tumors, 2 were microsatellite instability high, and 1 was microsatellite instability low.

Patients received IV cetuximab at 250 mg/m² over 60-90 minutes (day 1 and 8), with a first dose of 400 mg/m^2; mFOLFOX6 according to local standard – IV oxaliplatin at 85 mg/m² IV (day 1), IV leucovorin at 400 mg/m² IV (day 1), and IV bolus 5-fluorouracil at 400 mg/m² (day 1) and IV at 2,400 mg/m² (days 1-3); and IV avelumab at 10 mg/kg over 60-90 minutes (day 1 from cycle 2 onward).

The median number of treatment cycles was 8 (range, 1-34) for oxaliplatin, 13 (range, 1-35) for 5-fluorouracil, 12 (range, 1-35) for cetuximab, and 16 (range, 0-34) for avelumab. The median duration of cetuximab/avelumab treatment was 5.4 months (range, 0.7-18.4 months).

The study’s primary endpoint was 12-month PFS, and the researchers expected the PFS to rise from 40% to 57%. Unfortunately, the 12-month PFS was 40%, so the primary endpoint was not met.

However, the treatment produced a “very high” overall response rate at 81% (30/37), according to Dr. Tintelnot. A total of 4 patients achieved a complete response, 26 had a partial response, 4 had stable disease, and 3 progressed.

Dr. Tintelnot also noted a “promising” but “preliminary” overall survival rate – 84% at a median follow-up of 16.2 months. He said these results suggest PFS may not be the ideal endpoint for this combination.

Dr. Tintelnot said the combination was safe, with no unexpected toxicities. The most common grade 3-4 adverse events were infection of catheter, device, urinary tract, etc. (32%); abdominal pain, diarrhea, etc. (24%); skin reaction (21%); anemia, blood disorders, and hemolytic-uremic syndrome (18%); administration, infusion-related, and allergic reactions (16%); cognitive disturbance, meningism, syncope, and psychiatric disorders (16%); and peripheral sensory polyneuropathy and paresthesia (16%).

Dr. Tintelnot and colleagues also conducted translational research evaluating programmed death-ligand 1 (PD-L1) expression and serial circulating tumor DNA in patients on this trial.

The team found no clear correlation between PFS and T-cell diversification, tumor-infiltrating lymphocytes, or tumor proportion score. Dr. Tintelnot said this suggests classical predictive factors for PD-1/PD-L1 inhibitor treatment have a limited role with this combination.

The researchers did find that circulating tumor mutations might help predict early relapse with the regimen. The team identified 26 patients with mutations detectable in their blood. There was an immediate decline of circulating tumor mutations after treatment initiation, and reemergence of mutation clones was associated with progression.

Lastly, the researchers found that avelumab, cetuximab, and mFOLFOX6 suppressed the development of epidermal growth factor receptor–resistant subclones. There were no epidermal growth factor receptor mutations detected during follow-up.

This research was sponsored by AIO-Studien-gGmbH. Dr. Tintelnot disclosed no conflicts of interest.

SOURCE: Tintelnot J et al. SITC 2019, Abstract O16.
 

NATIONAL HARBOR, MD – An armored chimeric antigen receptor (CAR) T-cell therapy has demonstrated efficacy in vitro and in patients with relapsed or refractory non-Hodgkin lymphoma (NHL), according to findings presented at the annual meeting of the Society for Immunotherapy of Cancer.

Penn Medicine

ICTCAR014, a dominant negative PD-1 armored CAR T-cell therapy, proved more cytotoxic than traditional CAR T-cell therapy in vitro and produced responses in 12 of 13 NHL patients who received it.

Xiaobin Victor Lu, PhD, of Innovative Cellular Therapeutics, Shanghai, China, presented results with ICTCAR014 at the meeting.

Dr. Lu explained that ICTCAR014 consists of CD19-targeted CAR T cells genetically engineered to overexpress a PD-1 dominant negative protein with an altered intracellular signaling domain. The dominant negative protein can act as a “decoy receptor” to bind and block the PD-L1/2 inhibitory signal, thereby enhancing the efficacy of CAR T cells.

Innovative Cellular Therapeutics is developing ICTCAR014 because there is “some room to improve” with commercially available CAR T-cell products, Dr. Lu said. Specifically, tisagenlecleucel produced a 52% response rate in the JULIET trial (N Engl J Med. 2019;380:45-56), and axicabtagene ciloleucel produced an 82% response rate in the ZUMA-1 trial (N Engl J Med. 2017;377:2531-44).

There is also evidence to suggest that PD-1 blockade can modulate and “refuel” CAR T cells in relapsed/refractory NHL patients who fail or relapse after traditional anti-CD19 CAR T-cell therapy (Blood. 2017 Feb 23;129[8]:1039-41). This finding has prompted researchers to conduct trials of PD-1 inhibitors in combination with CAR T-cell therapies. But this combination approach may be expensive and cause more side effects than the armored CAR T-cell approach, Dr. Lu said.

In preclinical studies, Dr. Lu and colleagues found that ICTCAR014 was more effective than traditional anti-CD19 CAR T cells in killing Nalm6-PDL1 cells. In addition, the PD-1 dominant negative protein protected CAR T cells from exhaustion.

Dr. Lu also presented results in 13 NHL patients who have received ICTCAR014 in a phase 1 trial in China. Eleven patients had diffuse large B-cell lymphoma (DLBCL), and two had follicular lymphoma.

The objective response rate was 92.3% (12/13), which included five partial responses (38.5%) and seven complete responses (53.8%). Both follicular lymphoma patients and five DLBCL patients achieved a complete response. Five DLBCL patients achieved a partial response, and the remaining DLBCL patient did not respond.

Dr. Lu did not present safety data. However, he reported that there was no increased incidence of cytokine release syndrome or neurotoxicity in these patients, compared with patients receiving traditional CAR T-cell therapy.

Dr. Lu is employed by Innovative Cellular Therapeutics, which funded the research and is developing ICTCAR014.

[email protected]

SOURCE: Lu V et al. SITC 2019, Abstract O25.

NATIONAL HARBOR, MD – An armored chimeric antigen receptor (CAR) T-cell therapy has demonstrated efficacy in vitro and in patients with relapsed or refractory non-Hodgkin lymphoma (NHL), according to findings presented at the annual meeting of the Society for Immunotherapy of Cancer.

Penn Medicine

ICTCAR014, a dominant negative PD-1 armored CAR T-cell therapy, proved more cytotoxic than traditional CAR T-cell therapy in vitro and produced responses in 12 of 13 NHL patients who received it.

Xiaobin Victor Lu, PhD, of Innovative Cellular Therapeutics, Shanghai, China, presented results with ICTCAR014 at the meeting.

Dr. Lu explained that ICTCAR014 consists of CD19-targeted CAR T cells genetically engineered to overexpress a PD-1 dominant negative protein with an altered intracellular signaling domain. The dominant negative protein can act as a “decoy receptor” to bind and block the PD-L1/2 inhibitory signal, thereby enhancing the efficacy of CAR T cells.

Innovative Cellular Therapeutics is developing ICTCAR014 because there is “some room to improve” with commercially available CAR T-cell products, Dr. Lu said. Specifically, tisagenlecleucel produced a 52% response rate in the JULIET trial (N Engl J Med. 2019;380:45-56), and axicabtagene ciloleucel produced an 82% response rate in the ZUMA-1 trial (N Engl J Med. 2017;377:2531-44).

There is also evidence to suggest that PD-1 blockade can modulate and “refuel” CAR T cells in relapsed/refractory NHL patients who fail or relapse after traditional anti-CD19 CAR T-cell therapy (Blood. 2017 Feb 23;129[8]:1039-41). This finding has prompted researchers to conduct trials of PD-1 inhibitors in combination with CAR T-cell therapies. But this combination approach may be expensive and cause more side effects than the armored CAR T-cell approach, Dr. Lu said.

In preclinical studies, Dr. Lu and colleagues found that ICTCAR014 was more effective than traditional anti-CD19 CAR T cells in killing Nalm6-PDL1 cells. In addition, the PD-1 dominant negative protein protected CAR T cells from exhaustion.

Dr. Lu also presented results in 13 NHL patients who have received ICTCAR014 in a phase 1 trial in China. Eleven patients had diffuse large B-cell lymphoma (DLBCL), and two had follicular lymphoma.

The objective response rate was 92.3% (12/13), which included five partial responses (38.5%) and seven complete responses (53.8%). Both follicular lymphoma patients and five DLBCL patients achieved a complete response. Five DLBCL patients achieved a partial response, and the remaining DLBCL patient did not respond.

Dr. Lu did not present safety data. However, he reported that there was no increased incidence of cytokine release syndrome or neurotoxicity in these patients, compared with patients receiving traditional CAR T-cell therapy.

Dr. Lu is employed by Innovative Cellular Therapeutics, which funded the research and is developing ICTCAR014.

[email protected]

SOURCE: Lu V et al. SITC 2019, Abstract O25.

NATIONAL HARBOR, MD – An armored chimeric antigen receptor (CAR) T-cell therapy has demonstrated efficacy in vitro and in patients with relapsed or refractory non-Hodgkin lymphoma (NHL), according to findings presented at the annual meeting of the Society for Immunotherapy of Cancer.

Penn Medicine

ICTCAR014, a dominant negative PD-1 armored CAR T-cell therapy, proved more cytotoxic than traditional CAR T-cell therapy in vitro and produced responses in 12 of 13 NHL patients who received it.

Xiaobin Victor Lu, PhD, of Innovative Cellular Therapeutics, Shanghai, China, presented results with ICTCAR014 at the meeting.

Dr. Lu explained that ICTCAR014 consists of CD19-targeted CAR T cells genetically engineered to overexpress a PD-1 dominant negative protein with an altered intracellular signaling domain. The dominant negative protein can act as a “decoy receptor” to bind and block the PD-L1/2 inhibitory signal, thereby enhancing the efficacy of CAR T cells.

Innovative Cellular Therapeutics is developing ICTCAR014 because there is “some room to improve” with commercially available CAR T-cell products, Dr. Lu said. Specifically, tisagenlecleucel produced a 52% response rate in the JULIET trial (N Engl J Med. 2019;380:45-56), and axicabtagene ciloleucel produced an 82% response rate in the ZUMA-1 trial (N Engl J Med. 2017;377:2531-44).

There is also evidence to suggest that PD-1 blockade can modulate and “refuel” CAR T cells in relapsed/refractory NHL patients who fail or relapse after traditional anti-CD19 CAR T-cell therapy (Blood. 2017 Feb 23;129[8]:1039-41). This finding has prompted researchers to conduct trials of PD-1 inhibitors in combination with CAR T-cell therapies. But this combination approach may be expensive and cause more side effects than the armored CAR T-cell approach, Dr. Lu said.

In preclinical studies, Dr. Lu and colleagues found that ICTCAR014 was more effective than traditional anti-CD19 CAR T cells in killing Nalm6-PDL1 cells. In addition, the PD-1 dominant negative protein protected CAR T cells from exhaustion.

Dr. Lu also presented results in 13 NHL patients who have received ICTCAR014 in a phase 1 trial in China. Eleven patients had diffuse large B-cell lymphoma (DLBCL), and two had follicular lymphoma.

The objective response rate was 92.3% (12/13), which included five partial responses (38.5%) and seven complete responses (53.8%). Both follicular lymphoma patients and five DLBCL patients achieved a complete response. Five DLBCL patients achieved a partial response, and the remaining DLBCL patient did not respond.

Dr. Lu did not present safety data. However, he reported that there was no increased incidence of cytokine release syndrome or neurotoxicity in these patients, compared with patients receiving traditional CAR T-cell therapy.

Dr. Lu is employed by Innovative Cellular Therapeutics, which funded the research and is developing ICTCAR014.

[email protected]

SOURCE: Lu V et al. SITC 2019, Abstract O25.

NATIONAL HARBOR, MD. – Sitravatinib may “restore or enhance” the activity of anti-PD-1 therapy in patients with checkpoint inhibitor–refractory urothelial carcinoma, an investigator reported at the annual meeting of the Society for Immunotherapy of Cancer.

Jennifer Smith/MDedge News

Clinical activity was observed with combination sitravatinib and nivolumab in patients with urothelial carcinoma who had disease progression on or after an immune checkpoint inhibitor and were previously treated with platinum-based chemotherapy.

“Up until a few years ago, the only therapies we had [for urothelial carcinoma] were cytotoxic, platinum-based chemotherapies,” said Pavlos Msaouel, MD, PhD, of the University of Texas MD Anderson Cancer Center, Houston.

“Thankfully, since 2016, immune checkpoint therapy has become part of our toolbox. But even with single-agent, approved immune checkpoint therapies, anti-PD-1/anti-PD-L1, the response rates are still low, around 20%, and durable responses are only seen in a subset of patients. So we have to do better, if possible, potentially by combining immune checkpoint therapies with other immunotherapies such as sitravatinib.”

Dr. Msaouel explained that sitravatinib inhibits a spectrum of related receptor tyrosine kinases, including TAM family receptors (TYRO3, Axl, and Mer), split family receptors (VEGFR2/PDGFR and c-KIT), and c-Met. Researchers are investigating sitravatinib in combination with nivolumab in a phase 2 trial of patients with urothelial carcinoma (NCT03606174). Dr. Msaouel presented results from one cohort on this trial – 33 patients who had previously received platinum-based chemotherapy and a PD-1/PD-L1 inhibitor.

At baseline, the patients’ median age was 68 years (range, 47-83 years), and 70% were male. Patients had metastatic (n = 30) or locally advanced (n = 3) disease. They had received a median of two (range, one to four) prior systemic therapies.

For this study, patients received oral sitravatinib at 120 mg daily and intravenous nivolumab at 240 mg every 2 weeks or 480 mg every 4 weeks on continuous 28-day cycles. Tumor assessments were performed every 8 weeks.

Results

Of the 22 patients evaluable for efficacy, 1 patient achieved a complete response, 5 had a partial response, 15 had stable disease, and 1 progressed. Eight patients had tumor regression greater than 30%.

Treatment duration exceeded 26 weeks in six patients. Nine patients, including four responders, were still on study at the data cutoff in mid-October.

“This ongoing trial continues to show promising clinical activity, including tumor regression and prolonged duration on treatment,” Dr. Msaouel said.

He added that combination sitravatinib and nivolumab has “an acceptable side effect profile, with manageable adverse events.”

Common treatment-related adverse events, in all 33 patients, were fatigue (58%), diarrhea (48%), decreased appetite (33%), dysphonia (33%), nausea (33%), and alanine aminotransferase increase (21%).

Grade 3 treatment-related adverse events included fatigue (12%), hypertension (12%), diarrhea (9%), lipase increase (9%), decreased appetite (3%), and palmar-plantar erythrodysesthesia syndrome (3%). There were no grade 4 or 5 treatment-related events.

Mirati Therapeutics sponsored the trial. Dr. Msaouel disclosed relationships with Mirati, Bristol-Myers Squibb, Exelixis, Pfizer, and Takeda.

SOURCE: Msaouel P et al. SITC 2019. Abstract O23.

NATIONAL HARBOR, MD. – Sitravatinib may “restore or enhance” the activity of anti-PD-1 therapy in patients with checkpoint inhibitor–refractory urothelial carcinoma, an investigator reported at the annual meeting of the Society for Immunotherapy of Cancer.

Jennifer Smith/MDedge News

Clinical activity was observed with combination sitravatinib and nivolumab in patients with urothelial carcinoma who had disease progression on or after an immune checkpoint inhibitor and were previously treated with platinum-based chemotherapy.

“Up until a few years ago, the only therapies we had [for urothelial carcinoma] were cytotoxic, platinum-based chemotherapies,” said Pavlos Msaouel, MD, PhD, of the University of Texas MD Anderson Cancer Center, Houston.

“Thankfully, since 2016, immune checkpoint therapy has become part of our toolbox. But even with single-agent, approved immune checkpoint therapies, anti-PD-1/anti-PD-L1, the response rates are still low, around 20%, and durable responses are only seen in a subset of patients. So we have to do better, if possible, potentially by combining immune checkpoint therapies with other immunotherapies such as sitravatinib.”

Dr. Msaouel explained that sitravatinib inhibits a spectrum of related receptor tyrosine kinases, including TAM family receptors (TYRO3, Axl, and Mer), split family receptors (VEGFR2/PDGFR and c-KIT), and c-Met. Researchers are investigating sitravatinib in combination with nivolumab in a phase 2 trial of patients with urothelial carcinoma (NCT03606174). Dr. Msaouel presented results from one cohort on this trial – 33 patients who had previously received platinum-based chemotherapy and a PD-1/PD-L1 inhibitor.

At baseline, the patients’ median age was 68 years (range, 47-83 years), and 70% were male. Patients had metastatic (n = 30) or locally advanced (n = 3) disease. They had received a median of two (range, one to four) prior systemic therapies.

For this study, patients received oral sitravatinib at 120 mg daily and intravenous nivolumab at 240 mg every 2 weeks or 480 mg every 4 weeks on continuous 28-day cycles. Tumor assessments were performed every 8 weeks.

Results

Of the 22 patients evaluable for efficacy, 1 patient achieved a complete response, 5 had a partial response, 15 had stable disease, and 1 progressed. Eight patients had tumor regression greater than 30%.

Treatment duration exceeded 26 weeks in six patients. Nine patients, including four responders, were still on study at the data cutoff in mid-October.

“This ongoing trial continues to show promising clinical activity, including tumor regression and prolonged duration on treatment,” Dr. Msaouel said.

He added that combination sitravatinib and nivolumab has “an acceptable side effect profile, with manageable adverse events.”

Common treatment-related adverse events, in all 33 patients, were fatigue (58%), diarrhea (48%), decreased appetite (33%), dysphonia (33%), nausea (33%), and alanine aminotransferase increase (21%).

Grade 3 treatment-related adverse events included fatigue (12%), hypertension (12%), diarrhea (9%), lipase increase (9%), decreased appetite (3%), and palmar-plantar erythrodysesthesia syndrome (3%). There were no grade 4 or 5 treatment-related events.

Mirati Therapeutics sponsored the trial. Dr. Msaouel disclosed relationships with Mirati, Bristol-Myers Squibb, Exelixis, Pfizer, and Takeda.

SOURCE: Msaouel P et al. SITC 2019. Abstract O23.

NATIONAL HARBOR, MD. – Sitravatinib may “restore or enhance” the activity of anti-PD-1 therapy in patients with checkpoint inhibitor–refractory urothelial carcinoma, an investigator reported at the annual meeting of the Society for Immunotherapy of Cancer.

Jennifer Smith/MDedge News

Clinical activity was observed with combination sitravatinib and nivolumab in patients with urothelial carcinoma who had disease progression on or after an immune checkpoint inhibitor and were previously treated with platinum-based chemotherapy.

“Up until a few years ago, the only therapies we had [for urothelial carcinoma] were cytotoxic, platinum-based chemotherapies,” said Pavlos Msaouel, MD, PhD, of the University of Texas MD Anderson Cancer Center, Houston.

“Thankfully, since 2016, immune checkpoint therapy has become part of our toolbox. But even with single-agent, approved immune checkpoint therapies, anti-PD-1/anti-PD-L1, the response rates are still low, around 20%, and durable responses are only seen in a subset of patients. So we have to do better, if possible, potentially by combining immune checkpoint therapies with other immunotherapies such as sitravatinib.”

Dr. Msaouel explained that sitravatinib inhibits a spectrum of related receptor tyrosine kinases, including TAM family receptors (TYRO3, Axl, and Mer), split family receptors (VEGFR2/PDGFR and c-KIT), and c-Met. Researchers are investigating sitravatinib in combination with nivolumab in a phase 2 trial of patients with urothelial carcinoma (NCT03606174). Dr. Msaouel presented results from one cohort on this trial – 33 patients who had previously received platinum-based chemotherapy and a PD-1/PD-L1 inhibitor.

At baseline, the patients’ median age was 68 years (range, 47-83 years), and 70% were male. Patients had metastatic (n = 30) or locally advanced (n = 3) disease. They had received a median of two (range, one to four) prior systemic therapies.

For this study, patients received oral sitravatinib at 120 mg daily and intravenous nivolumab at 240 mg every 2 weeks or 480 mg every 4 weeks on continuous 28-day cycles. Tumor assessments were performed every 8 weeks.

Results

Of the 22 patients evaluable for efficacy, 1 patient achieved a complete response, 5 had a partial response, 15 had stable disease, and 1 progressed. Eight patients had tumor regression greater than 30%.

Treatment duration exceeded 26 weeks in six patients. Nine patients, including four responders, were still on study at the data cutoff in mid-October.

“This ongoing trial continues to show promising clinical activity, including tumor regression and prolonged duration on treatment,” Dr. Msaouel said.

He added that combination sitravatinib and nivolumab has “an acceptable side effect profile, with manageable adverse events.”

Common treatment-related adverse events, in all 33 patients, were fatigue (58%), diarrhea (48%), decreased appetite (33%), dysphonia (33%), nausea (33%), and alanine aminotransferase increase (21%).

Grade 3 treatment-related adverse events included fatigue (12%), hypertension (12%), diarrhea (9%), lipase increase (9%), decreased appetite (3%), and palmar-plantar erythrodysesthesia syndrome (3%). There were no grade 4 or 5 treatment-related events.

Mirati Therapeutics sponsored the trial. Dr. Msaouel disclosed relationships with Mirati, Bristol-Myers Squibb, Exelixis, Pfizer, and Takeda.

SOURCE: Msaouel P et al. SITC 2019. Abstract O23.

NATIONAL HARBOR, MD. – A TLR9 agonist called CMP-001 can reverse resistance to anti–programmed death-1 (PD-1) therapy in patients with melanoma, a phase 1 trial suggests.

Jennifer Smith/MDedge News

Combination CMP-001 and pembrolizumab produced durable responses in patients who had progressed on prior anti–PD-1 therapy, and the combination was considered well tolerated.

CMP-001 is a CpG-A TLR9 agonist packaged in a viruslike particle, John Kirkwood, MD, of University of Pittsburgh Medical Center, explained in a late-breaking abstract at the annual meeting of the Society for Immunotherapy of Cancer. CMP-001 activates tumor-associated plasmacytoid dendritic cells and induces systemic tumor-specific CD8+ T-cell responses.

Dr. Kirkwood and associates are investigating CMP-001, given alone or in combination with pembrolizumab, in a phase 1 trial (NCT02680184) of patients with metastatic or unresectable melanoma who are refractory to anti–PD-1 therapy.

Data were presented on 144 patients who received CMP-001 in combination with pembrolizumab. About 40% of patients (39.6%) had elevated lactate dehydrogenase at baseline, and 32.6% had BRAF mutations.

All patients had received prior anti–PD-1 therapy alone (75%) and/or in combination (50%). For most patients (93.1%), their last response to anti–PD-1 therapy was progression.

For this study, the patients received intratumoral CMP-001 injections at a range of doses (1 mg, 3 mg, 5 mg, 7.5 mg, and 10 mg). CMP-001 was given weekly for either 2 weeks or 7 weeks, then every 3 weeks until discontinuation. There were two different formulations of CMP-001 given – 0.01% polysorbate 20 (PS20; n = 83) and 0.00167% PS20 (n = 61).
 

Safety

“CMP-001 in combination with pembrolizumab is very well tolerated, with no apparent increase in autoimmune toxicities associated with anti–PD-1,” Dr. Kirkwood said.

The most common treatment-related adverse events were flulike symptoms, including chills (72%), pyrexia (56%), fatigue (51%), nausea (45%), vomiting (29%), and headache (28%). Another common event was injection-site pain (28%).

The most common grade 3 adverse events were hypotension (n = 9) and hypertension (n = 7). Grade 4 events included hypotension, aspartate aminotransferase increase, and alanine aminotransferase increase (n = 1 for all). There were no grade 5 events.

Six patients discontinued treatment because of adverse events.
 

Response

The overall response rate was 25% (21/83) among patients who received the 0.01% PS20 formulation of CMP-001 and 11.5% (7/61) among patients who received the 0.00167% PS20 formulation.

Responses were similar in injected and noninjected target lesions. The median duration of response has not been reached at a median follow-up of 16.9 months.

“Intratumoral CMP-001 reverses resistance to anti–PD-1 in patients who have progressed on prior anti–PD-1 therapy,” Dr. Kirkwood said, adding that these data support further clinical development of CMP-001.

The research is sponsored by Checkmate Pharmaceuticals. Dr. Kirkwood disclosed relationships with Amgen, BMS, Immunocore, Iovance, Novartis, Elsevier, Castle, Merck, and Checkmate.

SOURCE: Kirkwood J et al. SITC 2019, Abstract O85.

NATIONAL HARBOR, MD. – A TLR9 agonist called CMP-001 can reverse resistance to anti–programmed death-1 (PD-1) therapy in patients with melanoma, a phase 1 trial suggests.

Jennifer Smith/MDedge News

Combination CMP-001 and pembrolizumab produced durable responses in patients who had progressed on prior anti–PD-1 therapy, and the combination was considered well tolerated.

CMP-001 is a CpG-A TLR9 agonist packaged in a viruslike particle, John Kirkwood, MD, of University of Pittsburgh Medical Center, explained in a late-breaking abstract at the annual meeting of the Society for Immunotherapy of Cancer. CMP-001 activates tumor-associated plasmacytoid dendritic cells and induces systemic tumor-specific CD8+ T-cell responses.

Dr. Kirkwood and associates are investigating CMP-001, given alone or in combination with pembrolizumab, in a phase 1 trial (NCT02680184) of patients with metastatic or unresectable melanoma who are refractory to anti–PD-1 therapy.

Data were presented on 144 patients who received CMP-001 in combination with pembrolizumab. About 40% of patients (39.6%) had elevated lactate dehydrogenase at baseline, and 32.6% had BRAF mutations.

All patients had received prior anti–PD-1 therapy alone (75%) and/or in combination (50%). For most patients (93.1%), their last response to anti–PD-1 therapy was progression.

For this study, the patients received intratumoral CMP-001 injections at a range of doses (1 mg, 3 mg, 5 mg, 7.5 mg, and 10 mg). CMP-001 was given weekly for either 2 weeks or 7 weeks, then every 3 weeks until discontinuation. There were two different formulations of CMP-001 given – 0.01% polysorbate 20 (PS20; n = 83) and 0.00167% PS20 (n = 61).
 

Safety

“CMP-001 in combination with pembrolizumab is very well tolerated, with no apparent increase in autoimmune toxicities associated with anti–PD-1,” Dr. Kirkwood said.

The most common treatment-related adverse events were flulike symptoms, including chills (72%), pyrexia (56%), fatigue (51%), nausea (45%), vomiting (29%), and headache (28%). Another common event was injection-site pain (28%).

The most common grade 3 adverse events were hypotension (n = 9) and hypertension (n = 7). Grade 4 events included hypotension, aspartate aminotransferase increase, and alanine aminotransferase increase (n = 1 for all). There were no grade 5 events.

Six patients discontinued treatment because of adverse events.
 

Response

The overall response rate was 25% (21/83) among patients who received the 0.01% PS20 formulation of CMP-001 and 11.5% (7/61) among patients who received the 0.00167% PS20 formulation.

Responses were similar in injected and noninjected target lesions. The median duration of response has not been reached at a median follow-up of 16.9 months.

“Intratumoral CMP-001 reverses resistance to anti–PD-1 in patients who have progressed on prior anti–PD-1 therapy,” Dr. Kirkwood said, adding that these data support further clinical development of CMP-001.

The research is sponsored by Checkmate Pharmaceuticals. Dr. Kirkwood disclosed relationships with Amgen, BMS, Immunocore, Iovance, Novartis, Elsevier, Castle, Merck, and Checkmate.

SOURCE: Kirkwood J et al. SITC 2019, Abstract O85.

NATIONAL HARBOR, MD. – A TLR9 agonist called CMP-001 can reverse resistance to anti–programmed death-1 (PD-1) therapy in patients with melanoma, a phase 1 trial suggests.

Jennifer Smith/MDedge News

Combination CMP-001 and pembrolizumab produced durable responses in patients who had progressed on prior anti–PD-1 therapy, and the combination was considered well tolerated.

CMP-001 is a CpG-A TLR9 agonist packaged in a viruslike particle, John Kirkwood, MD, of University of Pittsburgh Medical Center, explained in a late-breaking abstract at the annual meeting of the Society for Immunotherapy of Cancer. CMP-001 activates tumor-associated plasmacytoid dendritic cells and induces systemic tumor-specific CD8+ T-cell responses.

Dr. Kirkwood and associates are investigating CMP-001, given alone or in combination with pembrolizumab, in a phase 1 trial (NCT02680184) of patients with metastatic or unresectable melanoma who are refractory to anti–PD-1 therapy.

Data were presented on 144 patients who received CMP-001 in combination with pembrolizumab. About 40% of patients (39.6%) had elevated lactate dehydrogenase at baseline, and 32.6% had BRAF mutations.

All patients had received prior anti–PD-1 therapy alone (75%) and/or in combination (50%). For most patients (93.1%), their last response to anti–PD-1 therapy was progression.

For this study, the patients received intratumoral CMP-001 injections at a range of doses (1 mg, 3 mg, 5 mg, 7.5 mg, and 10 mg). CMP-001 was given weekly for either 2 weeks or 7 weeks, then every 3 weeks until discontinuation. There were two different formulations of CMP-001 given – 0.01% polysorbate 20 (PS20; n = 83) and 0.00167% PS20 (n = 61).
 

Safety

“CMP-001 in combination with pembrolizumab is very well tolerated, with no apparent increase in autoimmune toxicities associated with anti–PD-1,” Dr. Kirkwood said.

The most common treatment-related adverse events were flulike symptoms, including chills (72%), pyrexia (56%), fatigue (51%), nausea (45%), vomiting (29%), and headache (28%). Another common event was injection-site pain (28%).

The most common grade 3 adverse events were hypotension (n = 9) and hypertension (n = 7). Grade 4 events included hypotension, aspartate aminotransferase increase, and alanine aminotransferase increase (n = 1 for all). There were no grade 5 events.

Six patients discontinued treatment because of adverse events.
 

Response

The overall response rate was 25% (21/83) among patients who received the 0.01% PS20 formulation of CMP-001 and 11.5% (7/61) among patients who received the 0.00167% PS20 formulation.

Responses were similar in injected and noninjected target lesions. The median duration of response has not been reached at a median follow-up of 16.9 months.

“Intratumoral CMP-001 reverses resistance to anti–PD-1 in patients who have progressed on prior anti–PD-1 therapy,” Dr. Kirkwood said, adding that these data support further clinical development of CMP-001.

The research is sponsored by Checkmate Pharmaceuticals. Dr. Kirkwood disclosed relationships with Amgen, BMS, Immunocore, Iovance, Novartis, Elsevier, Castle, Merck, and Checkmate.

SOURCE: Kirkwood J et al. SITC 2019, Abstract O85.

NATIONAL HARBOR, MD – PRS-343, a 4-1BB/HER2 bispecific molecule, has demonstrated safety and antitumor activity in patients with heavily pretreated, HER2-positive solid tumors, an investigator reported at the annual meeting of the Society for Immunotherapy of Cancer.

In a phase 1 trial of 18 evaluable patients, PRS-343 produced partial responses in 2 patients and enabled 8 patients to maintain stable disease. PRS-343 was considered well tolerated at all doses and schedules tested.

“PRS-343 is a bispecific construct targeting HER2 as well as 4-1BB,” said Geoffrey Y. Ku, MD, of Memorial Sloan Kettering Cancer Center in New York. “The HER2 component of the molecule localizes it into the tumor microenvironment of any HER2-positive cells. If the density of the HER2 protein is high enough, that facilitates cross-linkage of 4-1BB.

“4-1BB is an immune agonist that’s present in activated T cells, and cross-linkage helps to improve T-cell exhaustion and is also critical for T-cell expansion. The idea is that, by localizing 4-1BB activation to the tumor microenvironment, we can avoid some of the systemic toxicities associated with naked 4-1BB antibodies,” Dr. Ku added.

The ongoing, phase 1 trial of PRS-343 (NCT03330561) has enrolled 53 patients with a range of HER2-positive malignancies. To be eligible, patients must have progressed on standard therapy or have a tumor for which no standard therapy is available.

The most common diagnosis among enrolled patients is gastroesophageal cancer (n = 19), followed by breast cancer (n = 14), gynecologic cancers (n = 6), colorectal cancer (n = 5), and other malignancies.

The patients’ median age at baseline was 61 years (range, 29-92 years), and a majority were female (62%). Most patients (79%) had received three or more prior lines of therapy, including anti-HER2 treatments. Breast cancer patients had received a median of four anti-HER2 treatments, and gastric cancer patients had received a median of two.

The patients have been treated with PRS-343 at 11 dose levels, ranging from 0.0005 mg/kg to 8 mg/kg, given every 3 weeks. The highest dose, 8 mg/kg, was also given every 2 weeks.

Treatment-related adverse events (TRAEs) included infusion-related reactions (9%), fatigue (9%), chills (6%), flushing (6%), nausea (6%), diarrhea (6%), vomiting (5%), and noncardiac chest pain (4%).

“This was an extremely well-tolerated drug,” Dr. Ku said. “Out of 111 TRAEs, only a tiny proportion were grade 3, and toxicities mostly clustered around infusion-related reactions, constitutional symptoms, as well as gastrointestinal symptoms.”

Grade 3 TRAEs included infusion-related reactions (2%), fatigue (1%), flushing (3%), and noncardiac chest pain (1%). There were no grade 4-5 TRAEs.

At the data cutoff (Oct. 23, 2019), 18 patients were evaluable for a response at active dose levels (2.5 mg/kg, 5 mg/kg, and 8 mg/kg).

Two patients achieved a partial response, and eight had stable disease. “This translates to a response rate of 11% and a disease control rate of 55%,” Dr. Ku noted.

Both responders received PRS-343 at 8 mg/kg every 2 weeks. One of these patients had stage 4 gastric adenocarcinoma, and one had stage 4 gynecologic carcinoma.

Of the eight patients with stable disease, three received PRS-343 at 8 mg/kg every 2 weeks, two received 8 mg/kg every 3 weeks, one received the 5 mg/kg dose, and two received the 2.5 mg/kg dose.

Dr. Ku noted that the average time on treatment significantly increased in patients who received PRS-343 at 8 mg/kg every 2 weeks. Additionally, both responders and patients with stable disease had a “clear increase” in CD8+ T cells.

“[PRS-343] has demonstrated antitumor activity in heavily pretreated patients across multiple tumor types, and the treatment history, specifically the receipt of prior anti-HER2 therapy, indicates this is a 4-1BB-driven mechanism of action,” Dr. Ku said. “Based on these results, future studies are planned for continued development in defined HER2-positive indications.”

The current study is sponsored by Pieris Pharmaceuticals. Dr. Ku disclosed relationships with Arog Pharmaceuticals, AstraZeneca, Bristol-Myers Squibb, Daiichi Sankyo, Eli Lilly, Merck, Zymeworks, and Pieris Pharmaceuticals.

SOURCE: Ku GY et al. SITC 2019, Abstract O82.
 

NATIONAL HARBOR, MD – PRS-343, a 4-1BB/HER2 bispecific molecule, has demonstrated safety and antitumor activity in patients with heavily pretreated, HER2-positive solid tumors, an investigator reported at the annual meeting of the Society for Immunotherapy of Cancer.

In a phase 1 trial of 18 evaluable patients, PRS-343 produced partial responses in 2 patients and enabled 8 patients to maintain stable disease. PRS-343 was considered well tolerated at all doses and schedules tested.

“PRS-343 is a bispecific construct targeting HER2 as well as 4-1BB,” said Geoffrey Y. Ku, MD, of Memorial Sloan Kettering Cancer Center in New York. “The HER2 component of the molecule localizes it into the tumor microenvironment of any HER2-positive cells. If the density of the HER2 protein is high enough, that facilitates cross-linkage of 4-1BB.

“4-1BB is an immune agonist that’s present in activated T cells, and cross-linkage helps to improve T-cell exhaustion and is also critical for T-cell expansion. The idea is that, by localizing 4-1BB activation to the tumor microenvironment, we can avoid some of the systemic toxicities associated with naked 4-1BB antibodies,” Dr. Ku added.

The ongoing, phase 1 trial of PRS-343 (NCT03330561) has enrolled 53 patients with a range of HER2-positive malignancies. To be eligible, patients must have progressed on standard therapy or have a tumor for which no standard therapy is available.

The most common diagnosis among enrolled patients is gastroesophageal cancer (n = 19), followed by breast cancer (n = 14), gynecologic cancers (n = 6), colorectal cancer (n = 5), and other malignancies.

The patients’ median age at baseline was 61 years (range, 29-92 years), and a majority were female (62%). Most patients (79%) had received three or more prior lines of therapy, including anti-HER2 treatments. Breast cancer patients had received a median of four anti-HER2 treatments, and gastric cancer patients had received a median of two.

The patients have been treated with PRS-343 at 11 dose levels, ranging from 0.0005 mg/kg to 8 mg/kg, given every 3 weeks. The highest dose, 8 mg/kg, was also given every 2 weeks.

Treatment-related adverse events (TRAEs) included infusion-related reactions (9%), fatigue (9%), chills (6%), flushing (6%), nausea (6%), diarrhea (6%), vomiting (5%), and noncardiac chest pain (4%).

“This was an extremely well-tolerated drug,” Dr. Ku said. “Out of 111 TRAEs, only a tiny proportion were grade 3, and toxicities mostly clustered around infusion-related reactions, constitutional symptoms, as well as gastrointestinal symptoms.”

Grade 3 TRAEs included infusion-related reactions (2%), fatigue (1%), flushing (3%), and noncardiac chest pain (1%). There were no grade 4-5 TRAEs.

At the data cutoff (Oct. 23, 2019), 18 patients were evaluable for a response at active dose levels (2.5 mg/kg, 5 mg/kg, and 8 mg/kg).

Two patients achieved a partial response, and eight had stable disease. “This translates to a response rate of 11% and a disease control rate of 55%,” Dr. Ku noted.

Both responders received PRS-343 at 8 mg/kg every 2 weeks. One of these patients had stage 4 gastric adenocarcinoma, and one had stage 4 gynecologic carcinoma.

Of the eight patients with stable disease, three received PRS-343 at 8 mg/kg every 2 weeks, two received 8 mg/kg every 3 weeks, one received the 5 mg/kg dose, and two received the 2.5 mg/kg dose.

Dr. Ku noted that the average time on treatment significantly increased in patients who received PRS-343 at 8 mg/kg every 2 weeks. Additionally, both responders and patients with stable disease had a “clear increase” in CD8+ T cells.

“[PRS-343] has demonstrated antitumor activity in heavily pretreated patients across multiple tumor types, and the treatment history, specifically the receipt of prior anti-HER2 therapy, indicates this is a 4-1BB-driven mechanism of action,” Dr. Ku said. “Based on these results, future studies are planned for continued development in defined HER2-positive indications.”

The current study is sponsored by Pieris Pharmaceuticals. Dr. Ku disclosed relationships with Arog Pharmaceuticals, AstraZeneca, Bristol-Myers Squibb, Daiichi Sankyo, Eli Lilly, Merck, Zymeworks, and Pieris Pharmaceuticals.

SOURCE: Ku GY et al. SITC 2019, Abstract O82.
 

NATIONAL HARBOR, MD – PRS-343, a 4-1BB/HER2 bispecific molecule, has demonstrated safety and antitumor activity in patients with heavily pretreated, HER2-positive solid tumors, an investigator reported at the annual meeting of the Society for Immunotherapy of Cancer.

In a phase 1 trial of 18 evaluable patients, PRS-343 produced partial responses in 2 patients and enabled 8 patients to maintain stable disease. PRS-343 was considered well tolerated at all doses and schedules tested.

“PRS-343 is a bispecific construct targeting HER2 as well as 4-1BB,” said Geoffrey Y. Ku, MD, of Memorial Sloan Kettering Cancer Center in New York. “The HER2 component of the molecule localizes it into the tumor microenvironment of any HER2-positive cells. If the density of the HER2 protein is high enough, that facilitates cross-linkage of 4-1BB.

“4-1BB is an immune agonist that’s present in activated T cells, and cross-linkage helps to improve T-cell exhaustion and is also critical for T-cell expansion. The idea is that, by localizing 4-1BB activation to the tumor microenvironment, we can avoid some of the systemic toxicities associated with naked 4-1BB antibodies,” Dr. Ku added.

The ongoing, phase 1 trial of PRS-343 (NCT03330561) has enrolled 53 patients with a range of HER2-positive malignancies. To be eligible, patients must have progressed on standard therapy or have a tumor for which no standard therapy is available.

The most common diagnosis among enrolled patients is gastroesophageal cancer (n = 19), followed by breast cancer (n = 14), gynecologic cancers (n = 6), colorectal cancer (n = 5), and other malignancies.

The patients’ median age at baseline was 61 years (range, 29-92 years), and a majority were female (62%). Most patients (79%) had received three or more prior lines of therapy, including anti-HER2 treatments. Breast cancer patients had received a median of four anti-HER2 treatments, and gastric cancer patients had received a median of two.

The patients have been treated with PRS-343 at 11 dose levels, ranging from 0.0005 mg/kg to 8 mg/kg, given every 3 weeks. The highest dose, 8 mg/kg, was also given every 2 weeks.

Treatment-related adverse events (TRAEs) included infusion-related reactions (9%), fatigue (9%), chills (6%), flushing (6%), nausea (6%), diarrhea (6%), vomiting (5%), and noncardiac chest pain (4%).

“This was an extremely well-tolerated drug,” Dr. Ku said. “Out of 111 TRAEs, only a tiny proportion were grade 3, and toxicities mostly clustered around infusion-related reactions, constitutional symptoms, as well as gastrointestinal symptoms.”

Grade 3 TRAEs included infusion-related reactions (2%), fatigue (1%), flushing (3%), and noncardiac chest pain (1%). There were no grade 4-5 TRAEs.

At the data cutoff (Oct. 23, 2019), 18 patients were evaluable for a response at active dose levels (2.5 mg/kg, 5 mg/kg, and 8 mg/kg).

Two patients achieved a partial response, and eight had stable disease. “This translates to a response rate of 11% and a disease control rate of 55%,” Dr. Ku noted.

Both responders received PRS-343 at 8 mg/kg every 2 weeks. One of these patients had stage 4 gastric adenocarcinoma, and one had stage 4 gynecologic carcinoma.

Of the eight patients with stable disease, three received PRS-343 at 8 mg/kg every 2 weeks, two received 8 mg/kg every 3 weeks, one received the 5 mg/kg dose, and two received the 2.5 mg/kg dose.

Dr. Ku noted that the average time on treatment significantly increased in patients who received PRS-343 at 8 mg/kg every 2 weeks. Additionally, both responders and patients with stable disease had a “clear increase” in CD8+ T cells.

“[PRS-343] has demonstrated antitumor activity in heavily pretreated patients across multiple tumor types, and the treatment history, specifically the receipt of prior anti-HER2 therapy, indicates this is a 4-1BB-driven mechanism of action,” Dr. Ku said. “Based on these results, future studies are planned for continued development in defined HER2-positive indications.”

The current study is sponsored by Pieris Pharmaceuticals. Dr. Ku disclosed relationships with Arog Pharmaceuticals, AstraZeneca, Bristol-Myers Squibb, Daiichi Sankyo, Eli Lilly, Merck, Zymeworks, and Pieris Pharmaceuticals.

SOURCE: Ku GY et al. SITC 2019, Abstract O82.