Incyte said today its Phase III trial of Jakafi® (ruxolitinib) compared to best available therapy in patients with polycythemia vera met its primary endpoint of achieving phlebotomy independence and reducing spleen size by 35% or more.

As a result, Incyte said, it plans to file a supplemental NDA with FDA later this year seeking approval of a new indication for Jakafi. The selective JAK1/JAK2 inhibitor is now indicated for intermediate or high-risk myelofibrosis (MF), including primary MF, post–polycythemia vera MF, and post–essential thrombocythemia MF.

Incyte said topline data from the Phase III RESOPNSE trial showed Jakafi met the study’s primary endpoint–the proportion of patients whose hematocrit level is controlled in absence of phlebotomy and whose spleen volume is reduced by 35% or more from baseline as assessed by imaging at 32 weeks.

About 100,000 U.S. patients live with polycythemia vera, of which about 25% develop resistance to or intolerance of hydroxyurea, and are considered uncontrolled.

“One out of four patients with polycythemia vera remain uncontrolled despite existing standard therapies, and these patients face a profound symptom burden and are at greater risk of cardiovascular complications. These Phase III data give us confidence that ruxolitinib may offer a welcome new treatment option,” Herve Hoppenot, Incyte’s president and CEO, said in a statement.

Jakafi’s safety profile for polycythemia vera was generally consistent with previous studies based on initial review of the data, according to Incyte. In addition to safety, key secondary endpoints for RESPONSE included durable response and complete hematological remission.

In the RESPONSE trial, conducted at 109 sites, 222 patients with polycythemia vera resistant to or intolerant of hydroxyurea were randomized 1:1 to receive either Jakafi (10 mg twice-daily) or best available therapy. The dose was adjusted as needed throughout the trial, Incyte said.

RESPONSE is one of two Phase III trials designed to assess Jakafi in patients with polycythemia vera. Incyte said last month it expects data from other trial, RELIEF, to be available in mid-2014.

RESPONSE was conducted under a Special Protocol Assessment in collaboration with Novartis, which markets the drug outside the U.S. under the name Jakavi®.


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