Discussing ICIs in Endometrial Cancer for Cancer Immunotherapy Month

Maurie Markman, MD, president of medicine & science at Cancer Treatment Centers of America, addresses different treatment options, including checkpoint inhibitors, for patients with endometrial cancer.

Traditionally in this setting, physicians use platinum chemotherapy, such as paclitaxel, as well as hormone therapy to treat patients. Following the pattern seen in ovarian cancer, there have been no major advances until checkpoint inhibitors, according to Markman.

The first observation for when to use checkpoint inhibitors was whether patients with microsatellite instability (MSI)-high or microsatellite stable (MSS) disease. There was evidence that patients with MSI-high endometrial cancer respond to checkpoint inhibitors and 2 have been approved by the FDA in the second-line setting. These therapies had response rates of 50% to 60%, which Markman says is unheard of. Objective response rates to chemotherapy in this setting are in the 15% to 20% range.

For the patients with MSS disease, which is the majority, the response rates to checkpoint inhibitors has usually been lower. Markman says that similar to the chemotherapy in second line, checkpoint inhibitor responses ranged from 10% to 18% in these patients. However, there were data presented at the Society of Gynecologic Oncology annual meeting showing that a tyrosine kinase inhibitor combined with pembrolizumab (Keytruda) improved overall survival for patients with MSI-high or MSS endometrial cancer.