Momelotinib works by blocking specific enzymes called Janus Kinases (JAK1 and JAK2) and a protein called ACVR1. These enzymes and proteins are involved in the signaling pathways that control blood cell production and immune function. In myelofibrosis, these pathways are often overactive, leading to abnormal blood cell growth, inflammation, and symptoms like anemia and an enlarged spleen.

By inhibiting JAK1, JAK2, and ACVR1, momelotinib helps reduce abnormal cell signaling, which can decrease inflammation and improve blood cell counts. It also lowers the production of hepcidin, a hormone that restricts iron availability, thereby increasing red blood cell production and helping with anemia. This dual action makes momelotinib especially useful for people with myelofibrosis who have anemia.

momelotinib

Common brand names

Approved use in