Randomized study evaluating optimal dose, efficacy, and safety of E7386 plus lenvatinib versus treatment of physician's choice in advanced/recurrent endometrial carcinoma previously treated with platinum-based chemotherapy and immune checkpoint inhibitors.

Background: Randomized controlled trial data for patients with endometrial cancer who experience disease progression after anti-programmed cell death [ligand] 1 (PD-[L]1) therapy are lacking. E7386, a novel small-molecule inhibitor, has been shown to enhance anti-angiogenesis when combined with lenvatinib. The escalation and expansion parts of Study 102 showed preliminary anti-tumor activity and manageable safety of E7386 plus lenvatinib in patients with advanced, un-resectable, or recurrent endometrial cancer previously treated with anti-PD-(L)1.

Primary objective: This study aimed to determine the optimal dose of E7386 in combination with lenvatinib.

Study hypothesis: E7386 plus lenvatinib will show a manageable safety profile and clinically meaningful anti-tumor activity in patients with advanced, un-resectable, or recurrent endometrial carcinoma previously treated with chemotherapy and anti-PD-(L)1 therapy.

Trial design: Study 102 is an open-label, global, phase 1b/2 trial. Patients with endometrial carcinoma will be randomized 1:1:1:1 to E7386 120 mg twice daily plus lenvatinib 14 mg once daily, E7386 60 mg twice daily plus lenvatinib 14 mg once daily, lenvatinib 24 mg once daily monotherapy, or treatment of physician's choice (doxorubicin 60 mg/m² once every 3 weeks or paclitaxel 80 mg/m² once weekly [3 weeks on/1 week off]).

Major inclusion/exclusion criteria: Eligible patients are aged ≥18 years with Eastern Cooperative Oncology Group performance status of 0 to 1 and must have advanced, un-resectable, or recurrent endometrial carcinoma that has progressed on/after prior platinum-based chemotherapy and PD-(L)1-directed therapy. Up to 3 previous lines of therapy are permitted. Individuals with prior treatment with lenvatinib or E7386 or known intolerance and/or known hypersensitivity to E7386, lenvatinib, doxorubicin, or paclitaxel, or any of their excipients, are not eligible to participate.

Primary end points: The primary end points are safety and the objective response rate per Response Evaluation Criteria in Solid Tumors version 1.1 by investigator assessment at week 24.

Sample size: The study aims to include 120 patients across approximately 80 investigational sites in North America, Europe, and Asia-Pacific regions. Estimated Dates for Completing Accrual and Presenting Results: Enrollment is expected to take approximately 9 months, with presentation of results in 2026.

Trial registration: The trial is registered at ClinicalTrials.gov, NCT04008797.