Merrimack Pharmaceuticals Announces Notification of Plan to Voluntary Delist Common Stock on NASDAQ Subject to Receipt of Stockholder Approval of Plan of Dissolution - Seite 2

Participants in the Solicitation

The Company and its executive officers and directors may be deemed to be participants in the solicitation of proxies from its stockholders with respect to the proposed Dissolution, the Plan of Dissolution and related matters, and any other matters to be voted on at the Special Meeting. Information regarding the names, affiliations and direct or indirect interests, by security holdings or otherwise, of such directors and executive officers in the solicitation are included in the Proxy Statement. Additional information regarding such directors and executive officers, and other important Company information, are included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2023, which was filed with the SEC on March 9, 2024, as amended by a Form 10-K/A and a Proxy Statement for its Special Meeting of Stockholders, each of which was filed with the SEC on March 21, 2024.

Information regarding the persons who may, under SEC rules, be deemed participants in the solicitation of proxies of the Company’s stockholders in connection with the proposed Dissolution, the Plan of Dissolution and related matters are forth in the Proxy Statement. These documents will be available free of charge as described in the preceding section.

For more information, visit https://www.merrimack.com.

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.