Dr Bockorny on Botensilimab Plus Balstilimab in Ovarian Cancer

Bruno B. Bockorny, MD, attending physician, Gastrointestinal Oncology, Beth Israel Deaconess Medical Center; assistant professor, medicine, Harvard Medical School, discusses findings from a phase 1a/b trial (NCT03860272) with the combination of botensilimab (AGEN1181) and balstilimab (AGEN2034) in patients with recurrent platinum-refractory or platinum-resistant ovarian cancer.

In this ongoing trial, patients receive botensilimab, a CTLA-4 inhibitor, at 1 mg/kg or 2 mg/kg every 6 weeks plus balstilimab, a PD-1 inhibitor, at 3 mg/kg every 2 weeks. Key end points are the incidence of adverse effects (AEs), overall response rate (ORR), disease control rate (DCR), duration of response, progression-free survival, and overall survival.

The patients evaluable for the safety and efficacy of the combination at the data cutoff had received a median of 4 prior lines of therapy, and high-grade serous ovarian cancer was the most common histologic subtype.

Dr Bockorny on the Efficacy of Botensilimab Plus Balstilimab

The ORR in this heavily pretreated patient population was 33%, with 1 patient achieving a complete response and 7 patients achieving a partial response, Bockorny says. These responses were also durable, Bockorny explains. Additionally, treatment with the combination led to a DCR of 67%.

Dr Bockorny on the Safety Profile of Botensilimab Plus Balstilimab

The safety profile with this combination was as the investigators expected with treatment with a CTLA-4 inhibitor, Bockorny notes. In total, 96% of patients experienced grade 1/2 treatment-related AEs (TRAEs), and 33% and 8% of patients had grades 3 and 4 TRAEs, respectively. The only grade 3/4 AE to occur in more than 1 patient was diarrhea/colitis, and no grade 5 AEs occurred. These higher-grade events were manageable, and no patients experienced pneuomonitis, hypophysitis, or myocarditis of any grade, Bockorny says. Importantly, treatment with botensilimab plus balstilimab led to few high-grade visceral toxicities outside of the gastrointestinal tract, Bockorny concludes.