Matthew Powell, MD, associate professor, Obstetrics and Gynecology, Division of Gynecologic Oncology, Washington University School of Medicine, discusses data with immunotherapy in ovarian cancer.

There have been several phase I and phase II studies in platinum-recurrent ovarian cancer, primary peritoneal, or fallopian tube cancer, says Powell. There have been both large and small studies, with PD-1/PD-L1 inhibitors such as atezolizumab (Tecentriq), nivolumab (Opdivo), avelumab (Bavencio), and pembrolizumab (Keytruda). Data have shown that there are some patients who respond to these agents, and when they do respond it is a long response.

Phase II studies evaluating efficacy in the recurrent population have been disappointing thus far. The largest study to date was with pembrolizumab, which enrolled over 300 patients. The response rate in this study was about 8%, Powell says. In other studies of patients with ovarian cancer, nivolumab and avelumab showed response rates of 15% and 11%, respectively.

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Matthew Powell, MD, associate professor, Obstetrics and Gynecology, Division of Gynecologic Oncology, Washington University School of Medicine, discusses data with immunotherapy in ovarian cancer.
 

Dr. Powell Discusses Data With Immunotherapy in Ovarian Cancer

Matthew Powell, MD, associate professor, Obstetrics and Gynecology, Division of Gynecologic Oncology, Washington University School of Medicine, discusses microsatellite instability (MSI) and mismatch repair deficiency (dMMR) as potential biomarkers in endometrial cancer.

About one-third of patients with newly diagnosed endometrial cancer will express MSI or dMMR, says Powell. Recent data suggests these factors could be predictive of immunotherapy response. Clinicians can find these molecular markers by using immunohistochemistry and testing the 4 major genes expressed in patients with dMMR. Next-generation sequencing is now used to test for MSI. Powell says that recent data show a 40% to 60% response rate in these patient populations when treated with immunotherapy. The best part about the responses, he adds, is that they seem to be durable.

These data suggest that every newly diagnosed patient with endometrial cancer should be tested for MSI and dMMR. These attributes are also seen in ovarian cancer, but very rarely, Powell says.

Matthew Powell, MD, associate professor, Obstetrics and Gynecology, Division of Gynecologic Oncology, Washington University School of Medicine, discusses microsatellite instability and mismatch repair deficiency as potential biomarkers in endometrial cancer.

Dr. Powell on MSI and dMMR as Potential Biomarkers in Endometrial Cancer

Matthew Powell, MD, associate professor, Obstetrics and Gynecology, Division of Gynecologic Oncology, Washington University School of Medicine, discusses immunotherapy in ovarian cancer.

Immunotherapy is an emerging area in the treatment landscape of gynecologic malignancies. Currently, there is only a small cohort of patients with ovarian cancer who have tumors that are microsatellite instability-high that respond to immunotherapy, Powell says. Pembrolizumab (Keytruda) has shown antitumor activity in patients with PD-L1—overexpressing ovarian cancer, according to results of the KEYNOTE-100 study.

The initial phase II studies looking at efficacy in recurrent ovarian cancer have been disappointing, Powell says. These low response rates have prompted investigators to look into combination therapy for these patients. Immunotherapy in combination with chemotherapy induces neoantigens, Powell says, and it may be a compelling combination. Anti-VEGF strategies and PARP inhibitors in combination with immunotherapy are also being investigated, Powell adds.

Matthew Powell, MD, associate professor, Obstetrics and Gynecology, Division of Gynecologic Oncology, Washington University School of Medicine, discusses immunotherapy in ovarian cancer.
 

Matthew Powell, MD

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Dr. Powell Discusses Data With Immunotherapy in Ovarian Cancer

Dr. Powell on MSI and dMMR as Potential Biomarkers in Endometrial Cancer

Dr. Powell Discusses Immunotherapy in Ovarian Cancer