The Food and Drug Administration (FDA) has approved Inrebic (fedratinib; Celgene) capsules to treat adult patients with intermediate-2 or high-risk primary or secondary (post-polycythemia vera or post-essential thrombocythemia) myelofibrosis.

Inrebic is an oral kinase inhibitor with activity against wild type and mutationally activated Janus Associated Kinase 2 (JAK2) and FMS-like tyrosine kinase 3 (FLT3). The approval was based on data from the JAKARTA (phase 3) and JAKARTA2 (phase 2) trials. 

The multicenter, randomized, double-blind, placebo-controlled JAKARTA study evaluated the efficacy and safety of Inrebic in patients with intermediate-2 or high-risk, primary or secondary (post-polycythemia vera or post-essential thrombocythemia) myelofibrosis who were previously untreated with a JAK inhibitor, had splenomegaly, and had a platelet count of ≥50 x 109/L (median baseline platelet count was 214 x 109/L; 16% <100 x 109/L and 84% ≥100 x 109/L).

Results showed a spleen volume reduction (primary end point) of ≥35% in 37% of patients (N=96) treated with Inrebic when assessed from baseline to the end of cycle 6 (week 24) compared with 1% of placebo treated patients (P <.0001). Additionally, 40% of Inrebic-treated patients (N=89) demonstrated a ≥50% improvement in Total Symptom Score (secondary end point), as measured by the modified Myelofibrosis Symptom Assessment Form (MFSAF) v2.0 diary, compared with 9% of placebo-treated patients (P <.0001).

Inrebic carries a Boxed Warning regarding the risk of serious and fatal encephalopathy, including Wernicke’s, a neurologic emergency resulting from thiamine deficiency. The most common adverse reactions reported with therapy include diarrhea, nausea, vomiting, fatigue and muscle spasms.

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“Prior to today, there was one FDA-approved drug to treat patients with myelofibrosis, a rare bone marrow disorder. Our approval today provides another option for patients,” said Richard Pazdur, MD, director of the FDA’s Oncology Center of Excellence and acting director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research.

Inrebic will be supplied as 100mg capsules.

For more information visit celgene.com.

This article originally appeared on MPR