FDA Approves Treatment for Myelofibrosis Patients with Anemia

Published on: 

Anemia, experienced by most myelofibrosis patients, has caused over 30% of patients to discontinue their treatment.

On Sept. 15, 2023, GSK announced that its myelofibrosis treatment, Ojjaara (momelotinib) had been approved by FDA. The approval covers treatment of intermediate or high-risk myelofibrosis in adults with anemia, regardless of prior therapies. According to GSK, this is the first and only treatment for myelofibrosis patients with anemia. Nearly every myelofibrosis patient will develop anemia, and over 30% discontinue their myelofibrosis treatments due to it. Ojjaara also treats constitutional symptoms and splenomegaly (enlargement of the spleen).

Ojjaara is a once-a-day, oral JAK1/JAK2 and activin A receptor type 1 (ACVR1) inhibitor. It works along three key signaling pathways: Janus kinase (JAK) 1, JAK2, and activin A receptor type 1 (ACVR1). Inhibition of JAK1 and JAK2 can improve constitutional symptoms and splenomegaly, while inhibition of ACVR1 can decrease levels of the protein hepcidin, which contribute to anemia and are elevated in myelofibrosis. GSK held two Phase III, multicenter, randomized, double-blind studies testing the efficacy of Ojjaara in comparison to two other inhibitors used to treat myelofibrosis, danazol and ruxolitinib. Critically, while danazol and ruxolitinib can treat constitutional symptoms and splenomegaly associated with myelofibrosis, neither of them have been able to treat anemia.


Myelofibrosis is a rare blood cancer that can lead to severely low blood counts, which include anemia and thrombocytopenia. GSK stated that around 40% of patients have moderate to severe anemia at the time of diagnosis, and nearly all patients develop anemia while suffering from the disease. Treatment for myelofibrosis patients with anemia often involves blood transfusions, and more than 30% of patients discontinue myelofibrosis treatment because of anemia. Those that depend on transfusions often have a shortened survival rate. GSK hopes that by targeting anemia, it will make a “significant difference in the treatment regimen for these patients who have limited options to address these aspects of the disease.”

Source: GSK