Merrimack Pharmaceuticals, Inc. Announces Stockholder Approval of Plan of Dissolution And Cash Liquidating Dividend Amount of $15.10 Per Share of Common Stock

Merrimack Pharmaceuticals, Inc. (Nasdaq: MACK) (“Merrimack” or the “Company”) announced that the stockholders at a Special Meeting held today overwhelmingly approved adopting a Plan of Dissolution. Following that announcement, the Board of Directors declared a liquidating cash dividend in the amount of $15.10 per share. The dividend is expected to be paid on or about May 17, 2024. Merrimack’s Common Stock will trade on NASDAQ through May 17, 2024 and will delist from NASDAQ on May 20, 2024.

“We appreciate shareholder support for the plan of dissolution and the opportunity to fulfill our commitment to return milestone proceeds to the shareholders” said Gary Crocker, CEO and Chairman of Merrimack’s Board of Directors.

It is also possible that any distribution could be followed in the future by additional distributions, if it is determined that any reserved amounts no longer need to be reserved. Also, although not anticipated currently, additional amounts could be distributed in the event additional milestones are achieved under the Ipsen and Elevation Oncology agreements.

ABOUT MERRIMACK

Merrimack Pharmaceuticals, Inc. is a biopharmaceutical company based in Cambridge, Massachusetts that is entitled to receive up to $450.0 million in contingent milestone payments related to its sale of Onivyde to Ipsen S.A. in April 2017. Merrimack received $225 million of these potential milestone payments which were tied to the first line metastatic pancreatic ductal adenocarcinoma potential indication on March 27, 2024. The remaining contingent milestone payments consist of $150 million tied to the small cell lung cancer potential indication and $75 million tied to other potential applications Ipsen may elect to pursue. These contingent milestone payments would be payable by Ipsen upon approval by the U.S. Food and Drug Administration (“FDA”) of Onivyde for certain additional clinical indications. Merrimack’s agreement with Ipsen does not require Ipsen to provide Merrimack with any information on the progress of Onivyde clinical trials that is not publicly available. Merrimack is also entitled to receive up to $54.5 million in contingent milestone payments related to its sale of anti-HER3 programs to Elevation Oncology (formerly 14ner Oncology, Inc.) in July 2019.