Fedratinib is primarily used in the treatment of myelofibrosis, a type of bone marrow disorder that disrupts the body's normal production of blood cells. It works by inhibiting the JAK2 enzyme, which is often mutated in patients with this condition, leading to abnormal cell growth. By targeting this pathway, fedratinib helps reduce symptoms such as spleen enlargement, fatigue, and night sweats, improving the quality of life for patients. It is particularly beneficial for those who have not responded well to other treatments or are ineligible for alternative therapies. Additionally, fedratinib is being investigated for its potential use in other myeloproliferative disorders, expanding its therapeutic applications.