Novartis has announced that the Phase III study of Jakavi (ruxolitinib) has met its primary endpoint of maintaining haematocrit control (red blood cell volume) without the need for phlebotomy and reducing spleen size in patients with polycythemia vera resistant to or intolerant of hydroxyurea.
Polycythemia vera is a chronic, incurable blood cancer associated with an overproduction of blood cells.
Phlebotomy is a procedure of removing blood from the body to reduce the concentration of red blood cells.
The pivotal, randomised Phase III study (RESPONSE) showed that the safety profile of ruxolitinib was generally consistent with previous studies based on initial review of the data.
The open-label study was conducted at 109 sites and 222 patients with polycythemia vera resistant to or intolerant of hydroxyurea were randomised 1:1 to receive either ruxolitinib (10mg twice-daily) or best available therapy that was defined as investigator selected monotherapy or observation only. Dose was adjusted as needed throughout the study.
Primary endpoint of the study is the proportion of patients whose haematocrit is controlled without phlebotomy and whose spleen volume is reduced by 35% or more from baseline as assessed by imaging at 32 weeks. The secondary endpoints include safety, durable response and complete hematological remission.
In August 2012, the European Commission has approved Jakavi, an oral inhibitor of the JAK 1 and JAK 2 tyrosine kinases, for the treatment of disease-related splenomegaly or symptoms in adult patients with primary myelofibrosis (also known as chronic idiopathic myelofibrosis), post-polycythemia vera myelofibrosis or post-essential thrombocythemia myelofibrosis.
Jakavi is currently approved in more than 55 countries including the EU, Canada and some countries in Asia, Latin and South America for patients with myelofibrosis, a debilitating and life-threatening blood cancer. Additional worldwide regulatory filings are underway.
Ruxolitinib has been licensed by Novartis from Incyte for development and commercialisation outside the US.
Jakavi is a registered trademark of Novartis in countries outside the US while Jakafi is a registered trademark of Incyte.
Previously, ruxolitinib received orphan drug status for myelofibrosis from European Commission and the US Food and Drug Administration.
Incyte is marketing Jakavi in the US under the name Jakafi for the treatment of patients with intermediate or high-risk myelofibrosis.
Safety and efficacy profile of Jakavi is yet to be established outside the approved indication.
Novartis Oncology president and Oncology Development and Medical Affairs global head Alessandro Riva said: "We plan to submit these data to worldwide regulatory agencies this year, as we seek to bring ruxolitinib to patients with polycythemia vera who are no longer responding to or are intolerant of prior therapy."
Novartis will present the study data at an upcoming medical congress and submitted to worldwide regulatory authorities in 2014.
Image: Blood smear from a patient with polycythemia vera. Photo: courtesy of Patho.