Investigational Myelofibrosis Drug Granted Priority Review by FDA

A publication from OncLive recently reported that the FDA has granted the experimental myelofibrosis drug Fedratinib a priority review designation, following Celgene Corporation’s submission of a New Drug Application (NDA) to the government agency.

About Myelofibrosis

Myelofibrosis is a type of leukemia – a cancer that affects the blood-forming tissues of the body. “Blood-forming tissues of the body” refers of course, primarily, to bone marrow.

Bone marrow is like the body’s blood factory. Red blood cells, most white blood cells, and platelets (the cells that help your blood clot when you get a cut) are all produced by bone marrow. In patients with myelofibrosis, healthy bone marrow becomes scarred over time. These scars disrupt the marrow’s production of blood.

Symptoms usually present slowly over time. Since myelofibrosis scars the bone marrow progressively over time, observable effects (weakness, tiredness, shortness of breath) can be muted when the disease is in its early stages. Many live with the illness for some time before they notice anything is wrong.

Though myelofibrosis develops slowly, symptoms can progressively get worse as the condition establishes itself. Some myelofibrosis patients go on to develop other, even more threatening types of leukemia.

About Fedratinib

Celgene Corporation’s experimental drug Fedratinib is a “highly selective” JAK2 inhibitor. JAK inhibitors are medications that inhibit the activity of one or more enzymes in the Janus kinase family. These are enzymes involved in a chemical signaling pathway called JAK-STAT. This pathway is genetically linked to important cell functions like reproduction, cell death, and tumor formation.

Impressive results from Fedratinib’s phase 2 and 3 trials demonstrated that the drug shows significant promise in easing the symptoms of myelofibrosis patients. The phase 3 trial, which was double-blind and placebo-controlled, found that 36% of patients administered 400mg of Fedratinib daily experienced a >50% reduction in the severity of their symptoms (quantitatively assessed via a modified Myelofibrosis Symptom Assessment Form). 34% of patients administered a 500mg daily dose of the drug enjoyed similar results. However, only 7% of respondents in the placebo group reported easingof their symptoms.

The results were extremely encouraging, and prompted the FDA to grant Fedratinib’s new drug application priority review. A new drug application is the finish line for pharmaceutical development – approval of an NDA is the last step before final marketing approval. The FDA is expected to rule on the NDA by September 3, 2019, as stipulated by the timetables established by the Prescription Drug User Fee Act.

Fedratinib, which was also earlier granted an orphan drug designation by the FDA, may represent the first significant treatment available to people living with myelofibrosis. If things progress smoothly on the FDA’s front, it could be possible to see Fedratinib gain final approval by the end of the year. That means it could potentially be available by early next year.


Fedratinib could be a breakthrough drug for those affected by myelofibrosis. Would you or anyone you know benefit from the drug’s approval? Share your story with Patient Worthy!

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