Axatilimab in Combination With Retifanlimab and Paclitaxel for the Treatment of Patients With Advanced or Metastatic Solid Tumors

This phase I/II trial tests the safety, side effects, and effectiveness of axatilimab in combination with retifanlimab and paclitaxel for the treatment of patients with a solid tumor that may have spread from where it first started to nearby tissue, lymph nodes, or distant parts of the body (advanced) or that has spread from where it first started (primary site) to other places in the body (metastatic). Axatilimab is a monoclonal antibody that may interfere with the ability of tumor cells to grow and spread. Immunotherapy with monoclonal antibodies, such as retifanlimab, may help the body's immune system attack the cancer, and may interfere with the ability of tumor cells to grow and spread. Paclitaxel is in a class of medications called antimicrotubule agents. It stops cancer cells from growing and dividing and may kill them. Giving axatilimab in combination with retifanlimab and paclitaxel may be safe, tolerable and/or effective in treating patients with advanced or metastatic solid tumors.

PRIMARY OBJECTIVES: I. Phase Ib: Determine the safety and tolerability of the combination of axatilimab, retifanlimab, and paclitaxel in patients with advanced solid tumors. II. Phase II: Determine the efficacy of the combination of axatilimab, retifanlimab, and paclitaxel in patients with advanced solid tumors. SECONDARY OBJECTIVES: I. Determine the safety and tolerability of the combination of axatilimab, retifanlimab, and paclitaxel in patients with advanced solid tumors treated in phase II. II. Explore treatment related changes in the tumor microenvironment (TME) following treatment with the combination of axatilimab, retifanlimab, and paclitaxel in advanced solid tumors. III. Assess predictive biomarkers of response in peripheral blood. OUTLINE: Patients receive axatilimab intravenously (IV) over 30 minutes on day -8, prior to cycle 1. Beginning in cycle 1 day 1, patients receive axatilimab IV over 30 minutes on days 8 and 22 of each cycle, retifanlimab IV over 30-60 minutes on day 1 of each cycle, and paclitaxel IV over 60 minutes on days 1, 8, and 15 of each cycle. Cycles repeat every 28 days in the absence of disease progression or unacceptable toxicity. Patients also undergo tumor biopsy, computed tomography (CT) scan, and blood sample collection throughout the study and may undergo magnetic resonance imaging (MRI) and/or positron emission tomography (PET) scan throughout the study. After completion of study treatment, patients are followed up at 30 and 90 days.