Efficacy and safety of envafolimab plus lenvatinib combined with etoposide in recurrent ovarian, peritoneal, and fallopian tube cancer: An open-label, single-arm study—The ENLEN-OC-001 study.

e17570 Background: Previous studies have shown that combination therapy of immune checkpoint inhibitors (ICIs) may demonstrate more satisfactory efficacy in patients with ovarian cancer compared to monotherapy. Envafolimab is the first globally approved subcutaneously administered PD-L1 monoclonal antibody, which means there is less hospitalization is required, providing the possibility of live-in care. We aim to assess the efficacy and safety of the combination therapy of envafolimab plus lenvatinib combined with etoposide in patients with platinum-resistant recurrent ovarian cancer. Methods: In this single-arm, open-label study, we recruit patients with platinum-resistant ovarian cancer at the Zhongda Hospital, Southeast University (China). The specific regimen consists of subcutaneous envafolimab at a dose of 400mg, oral lenvatinib (12mg per day for patients weighing ≥60kg; 8mg per day for patients weighing <60kg) once daily on a continuous basis, and oral etoposide at a dose of 50 mg once daily on days 1–14 of a 21-day cycle. Oral etoposide is administered for six to ten cycles. The treatment will continue until disease progression or adverse event. The primary endpoint is objective response rate (ORR) assessed by investigators according to RECIST 1.1 criteria. Disease control rate (DCR), duration of response (DoR), progression free survival (PFS), overall survival (OS) and safety are evaluated as secondary endpoints . Data are summarized by descriptive statistics; time-to event endpoints are analyzed using Kaplan-Meier method. Results: From Jun 18, 2022, to Oct 31, 2023, we screened 16 and enrolled 12 patients. At the data cutoff date (Nov 30, 2023), 5 (41.7%) patients had discontinued the study, and 7 (58.3%) patients remained on treatment. Median follow-up was 8.6 months (IQR: 3.3-17.7). Based on the data collected, Objective responses were achieved in 4 (36.3%; 95% CI 10.9–69.2) of 11 patients who had at least one post-baseline efficacy assessment. DCR was 81.8%( 95% CI 48.2–97.7) and median duration of response was 7.4 months (95% CI 4.2–NA). Median progression-free survival was 9 months (95% CI 5.5–NA) and median OS was not reached. The most common grade 3 or 4 adverse events were leukopenia (2 16.7%) and thrombocytopenia (2 16.7%). No serious adverse events and treatment-related deaths were recorded. Conclusions: The combination of envafolimab plus lenvatinib combined with etoposide shows promising efficacy and manageable toxicities in patients with platinum-resistant ovarian cancer. Clinical trial information: NCT05422183 .