FDA grants Orphan Drug Designation to YM BioSciences' JAK1/2 inhibitor

-JAK1/2 inhibitor currently in Phase II clinical study in myelofibrosis-

YM BioSciences Inc. (NYSE Amex: YMI, TSX:YM), announced that the Office of Orphan Products Development of the U.S. Food and Drug Administration (FDA) has granted Orphan Drug Designation to the Company's highly-selective JAK1/2 inhibitor, CYT387, for the treatment of myelofibrosis, a chronic debilitating unmet medical need, in which a patient's bone marrow is replaced by scar tissue, and for which treatment options are limited or unsatisfactory.

Orphan Drug Designation is granted to novel drugs or biologics that treat a rare disease or condition affecting fewer than 200,000 patients in the U.S. The designation provides the drug developer with a seven-year period of U.S. marketing exclusivity upon marketing approval for the designated indication, as well as with tax credits for clinical research costs, the ability to apply for annual grant funding, clinical research trial design assistance and the waiver of Prescription Drug User Fee Act (PDUFA) filing fees.

"CYT387 is a potent, oral JAK1/2 inhibitor that has been demonstrating very favorable biological activity data in our ongoing Phase I/II trial in myelofibrosis and the granting of Orphan Drug Designation is a key regulatory milestone for our CYT387 clinical development program," said Dr. Nick Glover, COO of YM BioSciences. "This event provides us with further support for our expanding commitment to this promising drug as we continue to broaden our investment in our CYT387 development program while concentrating on advancing the molecule towards an NDA-enabling study in myelofibrosis."

The compound is currently being investigated in an oral Phase I/II clinical study in myelofibrosis patients at Mayo Clinic, Rochester, New York with Dr. Ayalew Tefferi, Professor, Hematology as Study Chair. The company intends to expand the present program up to 120 patients at a maximum of six centers in the U.S., Canada and Australia, subject to regulatory approval.

The Company recently provided an update on the progress of the clinical study, including the finalization of dose-escalation, identification of reversible dose-limiting toxicities and commencement of dosing in the Phase II dose-confirmation portion of the study. Promising evidence of biological activity, including significant spleen size reduction, improvement in constitutional symptoms and favorable hematological changes, was also reported. Detailed safety and activity data for CYT387 are planned to be presented at the American Society of Hematology (ASH) meeting in Orlando, Florida in December this year.

SOURCE YM BioSciences Inc.