Archive for April, 2011

YM Biosciences’s JAK-2 Inhibitor for Myelofibrosis – Could this be the best in class?

Posted by lifetech on April 20th, 2011

The discovery of a JAK2 mutation in 2005 led many to believe that the future of myelofibrosis (MF), a chronic blood malignancy, was about to change, and several companies started to develop JAK2 inhibitors. Such hope was based on the successful Gleevec precedent which dramatically altered the outlook for chronic myeloid leukemia patients who carried the BCR-ABL genetic aberration. Yet, such hope was unfounded and expectations have appropriately toned down: JAK2 inhibitors seem less likely to change the natural history of MF. But interest remains high given that the class of agents is very active in MF;  JAK2 inhibition confers significant improvement in morbidity and quality of life primarily by shrinking the enlarged MF spleen and controlling constitutional symptoms. Incyte‘s and Novartis’ ruxolitinib is likely to be the first JAK2 inhibitor to reach the market, probably by year-end. But there is room for improvement as not all patients respond to tolerated doses and ruxolitinib does not correct anemia – an important predictor of survival. For this reason, YM Biosciences‘ intriguing early data for its compound CYT387 has generated a great buzz on the street. It seems to be associated with a highly impressive anemia response, which clearly differentiates it from the JAK2 inhibitor pack. If CYT387’s anemia effect is confirmed, it would represent a major marketing advantage. But is the effect real and why so many doubts? In our latest report, we dissect the CYT387 data trying to separate what is solid from what is problematic as a means to gauge whether this could be the true market leader.