FDA approval: Patients with myelofibrosis get another treatment

Food and Drug Administration has given approval to yet another treatment for patients with myelofibrosis .

The U.S. Food and Drug Administration has given its nod to Inrebic (fedratinib) capsules for the treatment of patients with myelofibrosis, a rare bone marrow disorder. Till now, there was only one FDA approved drug for the treatment of the condition but the approval provides another option for patients. Jakafi (ruxolitinib) was approved by the Food and Drug Administration in 2011.

Myelofibrosis is a chronic disorder where scar tissue forms in the bone marrow and the production of the blood cells moves from the bone marrow to the spleen and liver, causing organ enlargement. It can cause extreme fatigue, shortness of breath, pain below the ribs, fever, night sweats, itching and bone pain.

“The FDA is committed to encouraging the development of treatments for patients with rare diseases and providing alternative options, as not all patients respond in the same way," Richard Pazdur, director of the Oncology Center of Excellence of Food and Drug Administration, said in a press release.

The approval of Inrebic for intermediate-2 or high-risk primary or secondary (post-polycythemia vera or post-essential thrombocythemia) myelofibrosis was based on the results of a clinical trial where 289 patients with myelofibrosis were randomized to receive two different doses (400 mg or 500 mg daily by mouth) of fedratinib or placebo.

The clinical trial showed that:

• 35 of 96 patients treated with the fedratinib 400 mg daily dose (the dose recommended in the approved label) experienced a significant therapeutic effect (measured by greater than or equal to a 35% reduction from baseline in spleen volume at the end of cycle 6 (week 24) as measured by an MRI or CT scan with a follow-up scan four weeks later).


• 36 patients who received Inrebic treatment experienced greater than or equal to a 50% reduction in myelofibrosis-related symptoms, such as night sweats, itching, abdominal discomfort, feeling full sooner than normal, pain under ribs on the left side, and bone or muscle pain.

The prescribing information for Inrebic includes a Boxed Warning to advise health care professionals and patients about the risk of serious and fatal encephalopathy (brain damage or malfunction), including Wernicke’s, which is a neurologic emergency related to a deficiency in thiamine. Health care professionals are advised to assess thiamine levels in all patients prior to starting Inrebic, during treatment and as clinically indicated. If encephalopathy is suspected, Inrebic should be immediately discontinued.

Common side effects for patients taking Inrebic are diarrhea, nausea, vomiting, fatigue and muscle spasms. Health care professionals are cautioned that patients may experience severe anemia (low iron levels) and thrombocytopenia (low level of platelets in the blood). Patients should be monitored for gastrointestinal toxicity and for hepatic toxicity (liver damage). The dose should be reduced or stopped if a patient develops severe diarrhea, nausea or vomiting. Treatment with anti-diarrhoea medications may be recommended. Patients may develop high levels of amylase and lipase in their blood and should be managed by dose reduction or stopping the mediation. Inrebic must be dispensed with a patient Medication Guide that describes important information about the drug’s uses and risks.