Efficacy and safety of QL1706-based combination therapy in recurrent or metastatic endometrial carcinoma previously treated with chemotherapy and immune checkpoint inhibitors: A single-arm, prospective, phase II trial.

Abstract

TPS2694 Background: Patients with advanced endometrial cancer who have progressed after platinum-based chemotherapy and immune checkpoint inhibitors have limited subsequent treatment options and a very poor prognosis. Iparomlimab and tuvonralimab injection (QL1706) is a bifunctional combination antibody targeting both programmed cell death protein 1 (PD-1) and cytotoxic T-lymphocyte antigen 4 (CTLA-4), developed using the MabPair biotechnology platform. This study aims to evaluate the efficacy and safety of QL1706 combined with chemotherapy ± bevacizumab in patients with recurrent or metastatic endometrial cancer previously treated with immune checkpoint inhibitors. Methods: In this prospective, single-arm, multicenter phase II clinical trial, up to 30 participants will be enrolled. Eligible patients must be aged ≥18 years, have an Eastern Cooperative Oncology Group Performance Status score of 0 to 1, be diagnosed with recurrent or metastatic endometrial carcinoma, have previously received PD-(L)1 therapy for over 6 months, and have experienced disease progression during or after prior chemotherapy and PD-(L)1 targeted therapy. Up to two prior lines of systemic therapy are permitted. Patients who previously received PD-(L)1 plus CTLA-4 targeted therapy or discontinued anti-PD-1/PD-L1 antibody therapy due to related toxicities are excluded. Enrolled patients will receive QL1706 (5 mg/kg every 3 weeks) combined with chemotherapy (investigator’s choice, administered for 3–6 cycles) ± bevacizumab (15 mg/kg every 3 weeks) until disease progression, unacceptable toxicity, or other protocol-specified termination events. The primary endpoint is the objective response rate (ORR) as assessed by the investigator according to RECIST v1.1. Secondary endpoints include progression-free survival (PFS), overall survival (OS), duration of response (DoR), and safety. As of January 2026, 5 of the planned 30 patients have been enrolled. Clinical trial information: NCT06917092 .