The U.S. Food and Drug Administration (FDA) approved GSK’s Ojjaara (momelotinib) tablets on Sept. 15, 2023. It is a kinase inhibitor intended to treat myelofibrosis with anemia. Myelofibrosis is a group of blood cancers that result from mutations in a number of different genes, including those for Janus-associated kinases (JAK). By limiting the activity of JAK1 and JAK2, Ojjaara decreases abnormal blood cell formation due to aberrant JAK signaling. In addition, it blocks activin A receptor type 1 (ACVR1), thereby increasing supplies of iron and helping to boost the formation of red blood cells. No other currently available drug manages both myelofibrosis and anemia. The recommended dose is 200mg once each day and the wholesale acquisition cost (WAC) for Ojjaara is $26,900 for 30 tablets. A launch date and distribution network are still to be determined. Look here for Ojjaara’s complete prescribing information.
At a Glance
- Brand (Generic) Name: Ojjaara (momelotinib)
- Manufacturer: GSK
- Date Approved: Sept. 15, 2023
- Indication: to treat adults who have intermediate or high-risk myelofibrosis including primary or secondary cases with anemia
- Dosage Forms Available: 100mg, 150mg and 200mg oral tablets
- Launch Date: Not yet available
- Estimated Annual Cost: WAC of $322,800
- Myelofibrosis includes a group of rare blood cancers caused by over-activity of the signaling pathways controlled by JAKs. Mutations in blood-forming stem cells cause a high production of atypical blood cells that suppress normal blood cells and cause fibrosis within bone marrow.
- With up to 25,000 patients in the United States, myelofibrosis usually occurs spontaneously (primary), but 10% to 15% of cases are secondary to other conditions, such as essential thrombocytopenia and polycythemia vera.
- Although primary cases usually have no apparent triggers, as many as 60% of patients test positive for mutations in the JAK2 gene.
- Because bone marrow cannot produce enough normal blood cells, the spleen and liver begin to generate blood cells, which usually causes the organs to enlarge. Symptoms include anemia, fatigue, fever, night sweats, and pain below the left ribs.
- Ojjaara blocks the effects of JAK 1 and 2 to reduce the production of abnormal blood cells. It also interferes with ACVR1 (also called ALK-1) to increase supplies of iron, which helps to boost the formation of red blood cells.
- In the MOMENTUM clinical trial, 25% of patients treated with Ojjaara for 24 weeks showed a 50% or higher improvement in total symptom score, spleen size, and need for transfusions compared with 9% of patients receiving danazol, a steroid frequently used off-label to treat myelofibrosis with anemia.
- At 48 weeks of extended treatment, 97% of those who responded to Ojjaara maintained response and 20% of the individuals who did not respond during the initial trial achieved some positive reaction to treatment.
- Among study patients, the most common side effects included bacterial infections, diarrhea, dizziness, fatigue, nausea, and thrombocytopenia.
- Present myelofibrosis treatment includes chemotherapy (chemo), radiation, and splenectomy. To control anemia, drugs, and blood transfusions often are needed.
- A stem cell transplant from a donor is the only cure for myelofibrosis.
- Inrebic® (fedratinib) capsules, Jakafi® (ruxolitinib) tablets, and Vonjo® (pacritinib) capsules are other JAK inhibitors that are FDA-approved for treating myelofibrosis. They do not relieve anemia, however.