Trials demonstrated a 35% or more reduction in spleen size for over 40% of patients treated with this oral JAK inhibitor.
FDA approved Incyte’s Jakifi™ (ruxolitinib) for the treatment of patients with intermediate or high-risk myelofibrosis (MF), including primary MF, post-polycythemia vera MF, and post-essential thrombocythemia MF. The firm says the oral JAK 1 and JAK2 inhibitor is the first FDA-approved drug for treating myelofibrosis, and the first JAK inhibitor to be approved for any indication.
Clearance by the U.S. drug regulator under a priority review program was granted ahead of the drug’s December 3 PDUFA date. The approval was based on data from two randomized Phase III trials, Comfort-I and Comfort-2, which confirmed that patients treated using Jakafi demonstrated signficant reductions in splenomegaly, together with improvements in symptoms. The placebo-controlled Comfort-1 study was carried out by Incyte in 309 patients, and showed that 41.9% of treated patients experienced a 35% or more reduction in spleen volume at 24 weeks. At this time point the percentage of patients with a greater than or equal to 50% improvement in Total Symptom Score was 45.9%.
The Comfort-II study was carried out by Incyte’s ex-U.S. partner, Novartis, in 219 patients. The results showed that Jakafi therapy resulted in 28.5% of patients experiencing a 35% or more reduction in spleen volume at 48 weeks.
“FDA approval of Jakafi has the potential to transform the way we treat myelofibrosis,” comments Srdan Verstovsek, M.D., associate professor at the University of Texas MD Anderson Cancer Center Division of Medicine’s Department of Leukemia, who was principal investigator for Comfort-1. “In this Phase III clinical trial, we observed significant reductions in spleen size and significant improvements in symptoms. Importantly, these benefits were achieved early on, most within a month, and tended to be durable during treatment.”
Ruzolitinib is separately undergoing a randomized Phase II study as combination with capecitabine as a therapy for recurrent or treatment-refractory metastatic pancreatic cancer. An investigator-sponsored study in patients with lymphoma has also been initiated, along with multiple investigator-sponsored studies in adult and pediatric patients with advanced hematologic malignancies and solid tumors.
Incyte teamed up with Novartis to develop ruxolitinib back in 2009. Under terms of the deal, Novartis has exclusive rights to develp the commercialize the drug in all hematology-oncology indications outside the U.S.