MISSISSAUGA, ON, Nov. 7, 2011 /PRNewswire/ - YM BioSciences Inc. (NYSE Amex: YMI, TSX: YM), today announced it would report updated results from its Phase I/II myelofibrosis study of CYT387, a JAK1/JAK2 inhibitor, in a poster session to be held from 6:00pm - 8:00pm on Monday, December 12th at the 53rd Annual Meeting of the American Society of Hematology (ASH) being held in San Diego, California. The Company also reported updated results today from the study that were included in an abstract submitted to ASH in August 2011. At the time the ASH abstract was submitted, 163 patients had been recruited into the trial across the six study sites. The duration of treatment ranged from 0.25 to 20.4 months with a median duration of 6.6 months. Forty six subjects were transfusion dependent at baseline. Previous JAK inhibitor therapy was reported for 11% and previous IMiD therapy for 8% of enrolled subjects. Reductions in spleen size, improvements in constitutional symptoms and the achievement of transfusion independence were observed in subjects in the expanded multicenter study. CYT387 was well tolerated. Seventy three percent of subjects reported treatment-related adverse events, with the majority reported as Grade 1. The most common Grade 3-4 treatment related adverse events included thrombocytopenia and hyperlipasemia, occurring in 16% and 3% of subjects respectively. Twenty five of 163 (15%) of subjects had discontinued from the nine month core study, giving a retention rate of 85%. The authors of the abstract conclude that CYT387 appears to be well tolerated when administered in either a once or twice-daily dosing regimen, and shows substantial clinical activity in myelofibrosis, with improvements in splenomegaly and constitutional symptoms. In addition, CYT387 continues to demonstrate an ability to induce durable anemia responses in a subset of subjects.