CAMBRIDGE, Mass., July 16, 2012 (GLOBE NEWSWIRE) -- Merrimack
Pharmaceuticals, Inc. (Nasdaq:MACK) today announced the election of
James Quigley, CEO emeritus of Deloitte Touche Tohmatsu, Limited (the
Deloitte Global Network), to its Board of Directors. Merrimack is a
biopharmaceutical company dedicated to the discovery and development of
novel medicines for the treatment of cancer.

Quigley recently retired as a Senior Partner with Deloitte LLP. He is
the co-author of "As One: Individual Action, Collective Power" (2011),
a book that addresses the leadership challenge of creating environments
that inspire large groups to work together toward a common goal.
Quigley is engaged in numerous business organizations and committees
and brings a history of involvement in various business and community
groups including being the U.S. co-chairman of the TransAtlantic
Business Dialogue, a member of the Council on Competitiveness and a
former member of the U.S. Securities and Exchange Commission (SEC)
Advisory Committee on Improvements to Financial Reporting.

"Jim's experience as a leader in a global firm and his expertise in
financial reporting make him a fantastic addition to Merrimack as we
advance our portfolio of oncology therapeutics and diagnostics and
continue to build an innovative, global medicine company," said Gary
Crocker, Chairman of the Board of Merrimack.

Quigley earned a Bachelor of Science degree and an honorary Doctorate
of Business from Utah State University. He was awarded an honorary
degree of Doctor of Commercial Science from Bentley College in Waltham,
Massachusetts.

"I am delighted to join the Merrimack Board and appreciate the
privilege of working with Gary and the other Board members. I look
forward to supporting and guiding the management team in pursuit of
Merrimack's ambitious mission to transform drug development in a way
that will offer patients and physicians better treatment options and
outcomes," said Quigley.

Merrimack also announced today the resignation of Robert Gay, Ph.D. Gay
is the former Managing Director and Chief Executive Officer of Huntsman
Gay Global Capital, a private equity firm, which he co-founded in 2008
and, prior to that, was a Managing Director of Bain Capital for 16
years. Gay has served as a member of Merrimack's Board since 2007.

"Bob's expertise has been a great asset to Merrimack. We are grateful
for the guidance and support he has offered during his tenure on our
Board," said Robert Mulroy, President and CEO of Merrimack.

Quigley joins Board members Gary Crocker, Board Chairman and President
of Crocker Ventures; James Dresser, former Chief Administrative Officer
of The Boston Consulting Group; Gordon Fehr, Ph.D., former Chairman and
President of Pfizer Canada; John Mendelsohn, M.D., co-director of the
new Sheikh Khalifa Bin Zayed Al Nahyan Institute for Personalized
Cancer Therapy at MD Anderson and former President of MD Anderson from
1996 to 2011; Sarah Nash, former Vice Chairman of JPMorgan Chase &
Co.'s Investment Bank; Michael Porter, Ph.D., Bishop William Lawrence
University Professor at Harvard Business School; Anthony Sinskey,
Sc.D., co-founder of Merrimack and Professor of Microbiology and
Engineering Systems in the Biology Department at MIT; and Robert
Mulroy, President and CEO of Merrimack.

About Merrimack

Merrimack is a biopharmaceutical company discovering, developing and
preparing to commercialize innovative medicines paired with companion
diagnostics for the treatment of serious diseases, with an initial
focus on cancer. Merrimack applies Network Biology, its proprietary
systems biology-based approach to biomedical research, throughout the
research and development process. Merrimack currently has five targeted
therapeutic oncology candidates in clinical development.

Forward-looking statements

Any statements in this press release about Merrimack's future
expectations, plans and prospects constitute forward-looking statements
within the meaning of The Private Securities Litigation Reform Act of
1995, as amended. Actual results may differ materially from those
indicated by such forward-looking statements. Merrimack anticipates
that subsequent events and developments will cause its views to change.
However, while Merrimack may elect to update these forward-looking
statements at some point in the future, Merrimack specifically
disclaims any obligation to do so.


CONTACT: Kathleen Petrozzelli Gallagher, Corporate Communications
         Merrimack
         617-441-1043
         kgallagher@merrimackpharma.com
         
         Betsy Stevenson
         RaymondStevenson Healthcare Communications
         860-984-1424
         betsy@raymondstevenson.com