Alligator Bioscience announced that the U.S. Food and Drug Administration (FDA) has cleared the company's Investigational New Drug (IND) application, allowing the company to initiate the OPTIMIZE-2 Phase 2 trial evaluating its lead asset mitazalimab in urothelial carcinoma. Urothelial carcinoma accounts for approximately 90% of bladder cancers, which is the most common malignancy involving the urinary system, with 83,000 new patients and 16,700 deaths each year in the U.S. This open-label, multi-center study aims to assess the safety and efficacy of an immunotherapeutic combination of mitazalimab (CD40 mAb) and a PD-1 inhibitor, in adult patients with histologically confirmed urothelial carcinoma, and who have progressed following prior treatment with PD-(L) therapy. The study will take place in approximately 15 to 20 clinical sites across the U.S. and Europe.

OPTIMIZE-2 will consist of a dose-finding phase with two mitazalimab dose levels in combination with a PD-1 inhibitor to select a recommended Phase 2 dose (RP2D). Thereafter, patient enrolment will be expanded at the RP2D, enabling primary analysis. Objective response rate as per RECIST 1.1 criteria will be the primary efficacy endpoint of the study.

Alligator Bioscience expects the OPTIMIZE-2 study to begin in H1 2024, or earlier, subject to operational feasibility. Mitazalimab is currently being evaluated in OPTIMIZE-1, a Phase 1b/2 study assessing its safety and efficacy in combination with mFOLFIRINOX in patients with previously untreated metastatic pancreatic cancer. Interim efficacy results from the Phase 2 part of the trial announced in January demonstrated a 52% objective response rate.

Top-line data from this trial are expected in First Quarter 2024.