Momelotinib sulfate is primarily used in the treatment of myelofibrosis, a rare bone marrow disorder that disrupts the body's normal production of blood cells. It works by inhibiting specific enzymes known as JAK1 and JAK2, which are involved in the signaling pathways that contribute to the abnormal cell growth and inflammation seen in myelofibrosis. This helps to reduce symptoms such as enlarged spleen, anemia, and fatigue, improving the quality of life for patients. Additionally, it has shown potential in addressing anemia associated with myelofibrosis, making it a valuable option for patients who may not respond well to other treatments. Its targeted mechanism offers a more tailored approach to managing this complex condition.