Gilead Sciences to Acquire YM Biosciences

                  Gilead Sciences to Acquire YM Biosciences

PR Newswire

FOSTER CITY, CA AND MISSISSAUGA, ON, Dec. 12, 2012

- Adds Selective JAK Inhibitor to Growing Oncology and Inflammation Pipeline -

FOSTER CITY, CA AND MISSISSAUGA, ON, Dec. 12, 2012 /PRNewswire/ - Gilead
Sciences, Inc. (Nasdaq: GILD) and YM BioSciences Inc. (NYSE MKT: YMI, TSX: YM)
announced today that the companies have signed a definitive agreement under
which Gilead will acquire YM for U.S.$2.95 per share in cash. The transaction
has received the unanimous approval of YM's Board of Directors, and values YM
at approximately U.S.$510 million, with YM reporting C$125.5 million in cash
and cash equivalents as of September 30, 2012. Gilead plans to fund the
acquisition with cash on hand. The transaction is expected to close in the
first quarter of 2013.

YM's lead  drug  candidate,  CYT387, is  an  orally-administered,  once-daily, 
selective inhibitor of the  Janus kinase (JAK)  family, specifically JAK1  and 
JAK2. The JAK enzymes have been implicated in a number of disorders including
myeloproliferative diseases, inflammatory disorders  and certain cancers.  YM 
has reported positive results from a Phase 1/2 clinical trial of CYT387 in 166
patients with myelofibrosis,  a life-threatening myeloproliferative  disease. 
Pending completion of the  acquisition, Gilead intends  to initiate a  pivotal 
Phase 3 clinical trial of CYT387 in myelofibrosis in the second half of 2013.

"This acquisition represents  an opportunity to  add a complementary  clinical 
program in the area of hematologic cancers to our growing oncology portfolio,"
said  Norbert  W.  Bischofberger,  PhD,  Gilead's  Executive  Vice  President, 
Research and Development  and Chief Scientific  Officer. "Based on  promising 
Phase 2 data, we believe CYT387  could provide important clinical benefit  for 
patients with myelofibrosis, including  potential improvements with regard  to 
anemia and decreased  dependence on  blood transfusions. We  look forward  to 
advancing CYT387 into a Phase 3 study as quickly as possible and to  exploring 
its potential  in other  myeloproliferative  diseases with  significant  unmet 
medical need."

Myelofibrosis is  a progressive,  chronic bone  marrow disorder  in which  the 
marrow is replaced by  fibrous scar tissue, making  it difficult for the  bone 
marrow to sufficiently produce blood cells,  leading to anemia (low red  blood 
cell  count)  and   thrombocytopenia  (low  blood   platelet  count),   severe 
constitutional symptoms  and  spleen  enlargement.  JAK  inhibitors  modulate 
cytokine-stimulated intracellular  signalling  and  decrease  the  circulating 
levels of  proinflammatory  cytokines  associated  with  the  pathogenesis  of 
myelofibrosis.

"This agreement represents a positive outcome both for myelofibrosis  patients 
and for our shareholders. Gilead has the research and development capabilities
and the resources needed to  more fully realize the  potential of CYT387 as  a 
therapeutic advance  for  myelofibrosis  patients and  potentially  for  other 
indications," said Dr.Nick Glover, President and CEO of YM.

"Since our acquisition  of CYT387 nearly  three years ago,  YM has made  great 
progress in advancing CYT387  through the clinical, regulatory,  manufacturing 
and business development  processes. While  Gilead's acquisition  will end  a 
long, varied  and interesting  journey for  YM, we  are pleased  to have  this 
transaction  crystallize  the  present  value  of   thisimportanttherapeutic 
candidate," said Mr. David Allan, Chairman of YM.

In recent years, Gilead has sought to expand its R&D expertise in the area  of 
oncology through the appointment of leading cancer researchers and clinicians,
the establishment of  external scientific partnerships  and through  strategic 
acquisitions.  Gilead's  lead  compound  in  oncology,  idelalisib  (formerly 
referred to  as  GS-1101),  is  an  investigational,  first-in-class  specific 
inhibitor of the phosphoinositide-3 kinase (PI3K) delta isoform. Five Phase 3
studies of  idelalisib  in chronic  lymphocytic  leukemia (CLL)  and  indolent 
non-Hodgkin's lymphoma (iNHL) are progressing.

Gilead is  also conducting  Phase 2  clinical trials  of simtuzumab  (formerly 
referred  to  as  GS-6624),  an  investigational  monoclonal  antibody   (mAb) 
candidate targeting  the  human  lysyl  oxidase-like  2  (LOXL2)  protein,  in 
myelofibrosis, colorectal  cancer,  pancreatic  cancer  and  certain  fibrotic 
diseases.

CYT387, idelalisib  and  simtuzumab  are investigational  products  and  their 
safety and efficacy have not yet been established.

Terms of the Transaction
Under the terms of  the agreement, upon closing  of the proposed  transaction, 
shareholders of  YM will  receive  U.S.$2.95 per  common  share in  cash,  and 
holders of warrants and stock options will receive a cash payment equal to the
difference between U.S.$2.95 and the exercise  price of such warrant or  stock 
option. The  proposed  transaction  will  be  completed  through  a  plan  of 
arrangement under the provisions of the Companies Act (Nova Scotia).

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.

YM Forward-Looking Statement
This press release may contain forward-looking statements, which reflect  YM's 
current expectation regarding future events. These forward-looking  statements 
involve risks  and uncertainties  that  may cause  actual results,  events  or 
developments to be  materially different  from any future  results, events  or 
developments expressed  or implied  by such  forward-looking statements.  Such 
factors include, but are not limited to, shareholder approval of the  proposed 
Arrangement; YM's ability to obtain court, regulatory, and other approvals  in 
connection with the proposed  Arrangement; uncertainties as  to the timing  of 
the  Arrangement;  the  satisfaction  of  the  conditions  precedent  to   the 
completion of  the  Arrangement,  including that  a  governmental  entity  may 
prohibit, delay  or refuse  to  grant approval  for  the consummation  of  the 
Arrangement; changing market conditions; the successful and timely  completion 
of clinical studies; the establishment  of corporate alliances; the impact  of 
competitive products  and  pricing;  new  product  development;  uncertainties 
related to  the regulatory  approval process  or the  ability to  obtain  drug 
product in sufficient quantity or at standards acceptable to health regulatory
authorities to  complete clinical  trials or  to meet  commercial demand;  and 
other risks detailed from  time to time in  YM's ongoing quarterly and  annual 
reporting. Except as required by applicable securities laws, YM undertakes  no 
obligation to  publicly  update  or  revise  any  forward-looking  statements, 
whether as a result of new information, future events or otherwise.

Gilead Forward-Looking Statement
This press release includes forward-looking  statements within the meaning  of 
the Private  Securities Litigation  Reform Act  of 1995  that are  subject  to 
risks, uncertainties and other factors. All statements other than  statements 
of historical  fact  are  statements  that  could  be  deemed  forward-looking 
statements, including all statements regarding  the intent, belief or  current 
expectation of the companies'  and members of  their senior management  team. 
Forward-looking statements include, without limitation, the ability of  Gilead 
to advance  YM's  product pipeline,  including  CYT387, the  possibility  that 
Gilead will be unable to initiate a  Phase 3 trial of CYT387 in  myelofibrosis 
as currently anticipated; the possibility  of unfavorable results of  clinical 
trials of  CYT387,  idelalisib and  simtuzumab;  the expected  timing  of  the 
completion of the  transaction; and  the ability to  complete the  transaction 
considering the  various closing  conditions,  including that  a  governmental 
entity may prohibit, delay or refuse to grant approval for the consummation of
the transaction.  Investors  are  cautioned  that  any  such  forward-looking 
statements are  not guarantees  of future  performance and  involve risks  and 
uncertainties  and  are  cautioned  not  to  place  undue  reliance  on  these 
forward-looking statements. Actual results  may differ materially from  those 
currently anticipated due to a number  of risks and uncertainties. Risks  and 
uncertainties that could cause the actual results to differ from  expectations 
contemplated  by  forward-looking  statements  include:  the  effects  of  the 
transaction  on  relationships  with  employees,  customers,  other   business 
partners or  governmental  entities;  other business  effects,  including  the 
effects  of  industry,  economic  or  political  conditions  outside  of   the 
companies' control;  actual or  contingent liabilities;  and other  risks  and 
uncertainties detailed from time to time  in Gilead's Report on Form 10-Q  and 
for the quarter ended September 30, 2012. All forward-looking statements  are 
based on  information currently  available to  Gilead, and  Gilead assumes  no 
obligation to update any such forward-looking statements.

Additional Information and Where to Find It
Further  information  regarding  the  transaction  will  be  contained  in  an 
information circular that  YM will  prepare and  mail to  its shareholders  in 
connection with the YM shareholders'  meeting, with closing expected to  occur 
in the  first  quarter  of  2013.  YM shareholders  are  urged  to  read  the 
information circular once it becomes  available, as it will contain  important 
information concerning the proposed transaction. YM shareholders may obtain a
copy of the  arrangement agreement,  information circular,  and other  meeting 
materials when they become available at www.sec.gov and www.sedar.com.

This press release is for informational purposes only. It does not constitute
an offer  to  purchase  shares  of YM  or  a  solicitation  or  recommendation 
statement under the rules and regulations of the United States Securities  and 
Exchange Commission or other applicable laws.

For more information on Gilead Sciences, please visit the company's website at
  www.gilead.com, follow Gilead on Twitter (@GileadSciences) or call Gilead
             Public Affairs at 1-800-GILEAD-5 or 1-650-574-3000.

For more information on YM BioSciences, please visit the company's website at
    www.ymbiosciences.com or contact James Smith, VP Corporate Affairs at
                   905.361.9518 or jsmith@ymbiosciences.com

SOURCE YM BioSciences Inc.

Contact:

Gilead Contacts
Patrick O'Brien, Investors
(650) 522-1936

Nathan Kaiser, Media
(650) 522-1853

YM BioSciences Contact
James Smith, VP Corporate Affairs
(905) 361-9518
jsmith@ymbiosciences.com
 
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