The transaction will require the approval of YM shareholders at a special meeting of YM shareholders, to be held as soon as reasonably practicable and in any event on or before February 11, 2013. In addition to YM’s shareholder approval, closing of the transaction is subject to the satisfaction of certain other customary conditions, including court approval of the transaction, and applicable government and regulatory approvals, including expiration or termination of the waiting period under the United States Hart Scott Rodino Antitrust Improvements Act, and the review period under the Competition Act (Canada). The approval of Gilead shareholders is not required in connection with the proposed transaction.The arrangement agreement contains customary non-solicitation provisions, but permits YM, in certain circumstances, to terminate the arrangement and accept an unsolicited superior proposal, subject to fulfilling certain conditions. BofA Merrill Lynch and Bloom Burton & Co. serve as financial advisors, and Gowling Lafleur Henderson LLP, Heenan Blaikie LLP and Dorsey & Whitney LLP serve as legal advisors to YM in connection with the transaction. Gilead is advised by Wilson Sonsini Goodrich & Rosati, Professional Corporation and Blake Cassels and Graydon LLP. About YM YM BioSciences Inc. is a drug development company primarily focused on advancing CYT387, an orally administered inhibitor of both the JAK1 and JAK2 kinases, which have been implicated in a number of hematological and immune cell disorders including myeloproliferative neoplasms and inflammatory diseases as well as certain cancers. Positive interim results have been reported from a Phase 1/2 trial of CYT387 in 166 patients with myelofibrosis. In addition, YM has several preclinical programs underway with candidates from its library of novel compounds identified through internal research conducted at YM BioSciences Australia. About Gilead Sciences Gilead Sciences is a biopharmaceutical company that discovers, develops and commercializes innovative therapeutics in areas of unmet medical need. The company’s mission is to advance the care of patients suffering from life-threatening diseases worldwide. Headquartered in Foster City, California, Gilead has operations in North America, Europe and Asia Pacific.