ASCO 2026: Chemotherapy-Free Combination for Heavily Pretreated Platinum-Resistant Ovarian Cancer

By: Julia Cipriano, MS, CMPP
Posted: Tuesday, July 7, 2026

Joyce N. Barlin, MD, of Women’s Cancer Care Associates, Albany, New York, and colleagues reported clinically meaningful overall survival and a manageable safety profile with the investigational tumor microenvironment–selective regulatory T-cell–depleting antibody targeting CTLA-4 gotistobart plus pembrolizumab in a predominantly heavily pretreated population of patients with platinum-resistant ovarian cancer. These findings from an updated analysis of the phase II PRESERVE-004/GOG-3081 trial were presented at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting (Abstract 5511).  

Patients with platinum-resistant ovarian, tubal, or peritoneal cancer who previously received one line of platinum-based therapy and progressed between 3 and 6 months or had received at least one line and progressed within 6 months of their last dose were treated with gotistobart (1, 2, 3, or 6 mg/kg) plus pembrolizumab (200 mg) every 3 weeks. The present analysis reported outcomes for the 62 patients who were administered 1 or 2 mg/kg of gotistobart; 75.8% had received at least three prior lines of therapy.

Median overall survival was 18.9 months with 1 mg/kg of gotistobart and 8.3 months with 2 mg/kg, with corresponding 18-month overall survival rates of 54.3% and 26.9%. Confirmed objective response rates were 21.2% and 20.7%, respectively. Median duration of response was 10.8 and 11.6 months, and median progression-free survival was 2.2 and 2.5 months.

Grade 3 or higher treatment-related adverse events occurred in 51.5% of the 1-mg/kg cohort and 55.2% of the 2-mg/kg cohort. The most common were colitis (12.1% and 10.3%, respectively), hyponatremia (12.1% and 3.4%), increased alanine aminotransferase (9.1% and 3.4%), increased aspartate aminotransferase (9.1% and 3.4%), adrenal insufficiency (9.1% and 3.4%), diarrhea (9.1% and 3.4%), and hypokalemia (0% and 6.9%).

“The chemotherapy-free combination of gotistobart and pembrolizumab demonstrated clinically meaningful [objective response rate, overall survival], and a manageable safety profile in [patients with platinum-resistant ovarian cancer], where the majority were heavily pretreated with no further standard-of-care treatment options,” the investigators concluded.

Disclosure: For full disclosures of the study authors, visit coi.asco.org.

https://www.asco.org/abstracts-presentations/260972

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