Adding immunotherapy to standard chemotherapy may result in significantly longer progression-free survival for patients with advanced or recurrent endometrial cancer, according to the findings from two novel studies presented by Eskander et al and Mirza et al at the Society of Gynecologic Oncology (SGO) 2023 Annual Meeting on Women’s Cancer.
Background
“Patients with advanced stage or recurrent endometrial cancer, the most common type of gynecologic cancer in the United States, face a poor prognosis with limited treatment options,” explained first-trial lead study author Ramez N. Eskander, MD, Assistant Professor of Obstetrics, Gynecology, and Reproductive Sciences at the the University of California, San Diego. “This is particularly notable in patients who progress after platinum-based adjuvant therapy with disease not amenable to curative surgery or radiation,” he added.
First Study Methods and Findings
In the first trial—the randomized, blinded, phase III NRG Oncology NRG-GY-018 trial (ClinicalTrials.gov identifier: NCT03914612)—the researchers randomly assigned 816 patients with stage III or IVA, stage IVB, or recurrent endometrial cancer to receive either pembrolizumab plus chemotherapy or placebo plus chemotherapy across six cycles, followed by up to 14 cycles of maintenance pembrolizumab or placebo. The researchers highlighted that patients in the mismatch repair-proficient endometrial cancer cohort who received pembrolizumab and chemotherapy experienced progression-free survival with manageable adverse effects for 11.7 months vs 8.7 months among those receiving chemotherapy alone.
Second Study Methods and Findings
In the second trial—the randomized, blinded, phase III ENGOT-EN6-NSGO/GOG-3031/RUBY trial (ClinicalTrials.gov identifier: NCT03981796)—the researchers randomly assigned 494 patients with first recurrent or primary advanced stage III or IV endometrial cancer to receive either dostarlimab plus chemotherapy followed by monotherapy or placebo plus chemotherapy followed by monotherapy. Among the 245 patients who received treatment with both dostarlimab and chemotherapy, there was statistically significant and clinically meaningful progression-free survival benefits across all populations compared with the 249 patients who received chemotherapy alone. The researchers also observed an early trend toward improved overall survival in all populations.
Conclusions
“In the [NRG-]GY-018 study, we saw clinically meaningful improvement in [progression-free survival] in both study populations—an encouraging new finding. Future analyses will examine overall survival and quality of life outcomes,” concluded Dr. Eskander.
