Agenus Immunotherapy Combination Maintains Survival Milestone in Heavily Treated Ovarian Cancer Patients
Agenus released three-year follow-up data from its Phase 1b trial of botensilimab and balstilimab combination therapy in recurrent ovarian cancer, showing 48% overall survival in a heavily pretreated population. The durable survival rate remained stable from the two-year assessment, with 25% of treated patients alive and off all therapy at last follow-up. Results were observed across both platinum-sensitive and platinum-resistant disease subtypes.
Agenus tested a two-drug immunotherapy regimen designed to activate immune responses through distinct mechanisms. The trial enrolled over 400 patients but the ovarian cancer subset consisted of 44 individuals who had exhausted standard treatment pathways. The patient population represented a particularly challenging group: most had already undergone multiple rounds of chemotherapy and targeted agents, with the majority experiencing cancer that either progressed during platinum treatment or returned shortly after completion.
The key finding involved stability rather than improvement between year two and year three, with the 48% survival rate holding steady. Additionally, a quarter of all treated patients remained disease-free without ongoing therapy at final assessment, suggesting some individuals achieved durable remission following the combination treatment course.
These results could meaningfully affect treatment options for ovarian cancer patients with limited remaining alternatives, particularly those whose disease has become resistant to platinum-based chemotherapy. If confirmed in larger trials, the combination approach may reshape how physicians sequence immunotherapies in advanced disease, potentially offering extended survival for a subset of heavily pretreated patients. The finding that some patients maintained remission off-treatment could also influence clinical decision-making regarding treatment duration and monitoring protocols in this population.