Axatilimab

This phase Ib/II trial tests the best dose of axatilimab and effectiveness of axatilimab with or without azacitidine for the treatment of patients with advanced phase myeloproliferative neoplasms (MPN), myeloproliferative neoplasm/myelodysplastic syndrome (MPN/MDS) overlap or high risk chronic myelomonocytic leukemia (CMML). Axatilimab is an antibody that is cloned from a single white blood cell that is known to be able to recognize cancer cells and block a protein on the surface of the white blood cells that may be involved in cancer cell growth. By blocking the proteins, this may slow or halt the growth of the cancer. Azacitidine is in a class of medications called antimetabolites. It works by stopping or slowing the growth of cancer cells. Giving axatilimab with or without azacitidine may be safe and effective in treating patients with advanced phase MPN, MPN/MDS overlap or high risk CMML.