FDA Grants Fast Track to Momelotinib to Treat Myelofibrosis

The FDA granted a fast track designation to momelotinib for the treatment of patients with intermediate/high-risk myelofibrosis who have previously received a JAK inhibitor, according to Sierra Oncology — the drug’s manufacturer.

The JAK1, JAK2, and ACVR1 inhibitor will be evaluated in the randomized, double-blind phase III study — expected later this year – and compared with danazol in 180 patients with myelofibrosis who are symptomatic and anemic and have been treated previously with a JAK inhibitor.

Patients will be randomized 2:1 to receive either momelotinib or danazol. Total Symptom Score (TSS) response rate will serve as the primary endpoint. Secondary endpoints will include Transfusion Independence (TI) rate at week 24, splenic response rate (SRR) at week 24, duration of TSS response to week 48, transfusion dependence response rate, various measures of cumulative transfusion burden, and Patient Reported Outcome (PRO) measures of fatigue and physical function.

"Fast Track designation for momelotinib highlights the serious and significant unmet needs of patients with myelofibrosis who have previously received a JAK inhibitor. These patients typically suffer from uncontrolled constitutional symptoms, progressively worsening anemia often resulting in transfusion dependency, and enlarged spleens. Fast Track also recognizes the absence of FDA-approved treatments for these patients and that momelotinib has the potential to address their unmet needs," Barbara Klencke, MD, chief development officer of Sierra Oncology, said in the release. "We look forward to continuing to work closely with the FDA as we launch and conduct the MOMENTUM phase III trial of momelotinib, with the goal of bringing this important therapy to patients expeditiously."