Trial results for Nivolumab in combination with etigilimab in patients with platinum-resistant clear cell ovarian cancer were posted on 2026-07-08. The PHASE2 study, known as EON, reported an objective response rate between 15 percentage of participants and 30 percentage of participants for the combination, with a median duration of response of 8.6 months.
Background
Nivolumab is a well-known immune checkpoint inhibitor, a type of immunotherapy that helps the body's immune system fight cancer. This single-arm EON study investigated the potential benefit of adding etigilimab, another therapeutic agent, to nivolumab therapy. The study specifically targeted patients with platinum-resistant, recurrent epithelial ovarian cancer, including clear cell ovarian, fallopian tube, and primary peritoneal cancers. These forms of ovarian cancer are particularly challenging to treat due to their resistance to standard platinum-based chemotherapy, highlighting a significant unmet medical need for effective new treatment strategies.
Trial design
The EON study, identified as NCT05715216, was designed as a single-arm, open-label PHASE2 trial. It successfully enrolled 23 participants who had been diagnosed with platinum-resistant, recurrent epithelial ovarian cancer, encompassing clear cell ovarian, fallopian tube, and primary peritoneal cancers. The trial's primary objective was to thoroughly assess the Objective Response Rate of the combination of etigilimab and nivolumab in this specific patient population. Additionally, secondary objectives included evaluating the toxicity profile and the Duration of Response associated with the combined therapeutic regimen.
Key results
For the combination of etigilimab and nivolumab in patients with platinum-resistant clear cell ovarian cancer, the observed Objective Response Rate was reported to be between 15 percentage of participants and 30 percentage of participants. The Duration of Response for the combination therapy demonstrated a median of 8.6 months. Regarding the safety profile, two distinct measures for "The Toxicity of the Combination of Etigilimab and Nivolumab in Patients With Platinum Resistant Clear Cell Ovarian Cancer" were reported. One measure indicated toxicity in 47.8 percentage of participants, while another measure for the same outcome title was reported as affecting 0 percentage of participants.
What this means
The results from the EON PHASE2 study offer promising preliminary data regarding the efficacy and safety of combining nivolumab with etigilimab for patients facing platinum-resistant clear cell ovarian cancer. The objective response rate, ranging from 15 percentage of participants to 30 percentage of participants, along with a median duration of response of 8.6 months, suggests that this combination may represent a viable therapeutic option in a patient population with limited alternatives. These findings warrant further investigation to confirm the clinical benefit and to fully characterize the safety profile, especially considering the different toxicity percentages reported. The study addresses a critical need for new treatments in this difficult-to-treat cancer type.
Source
These trial results were posted on ClinicalTrials.gov on 2026-07-08. The full details of the study, NCT05715216, are available on clinicaltrials.gov.