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

Merrimack Pharmaceuticals, Inc. (Nasdaq: MACK) (“Merrimack” or the “Company”) today announced that it has filed notice with NASDAQ of the Company’s intent to delist its securities from NASDAQ, subject to receipt of stockholder approval of the Plan of Dissolution at the Special Meeting of Stockholders of Merrimack scheduled to be held on Friday, May 10, 2024. Under the Plan of Dissolution, Merrimack intends to issue an initial liquidating cash dividend to its stockholders, subject to receipt of stockholder approval of the Plan of Dissolution.

The Company currently estimates a cash dividend for the initial liquidating distribution in the range of $14.92 to $15.15 per share. Such range is an estimate and the actual cash dividend amount, which is expected to be announced on or about May 8, 2024, may fall outside of this range and is subject to approval of the Plan of Dissolution by stockholders at the Special Meeting.

May 10, 2024 will be the record date for the determination of stockholders of record to receive the liquidating dividend. The current plan, assuming stockholder approval of the Plan of Dissolution, is for the stock to go ex-dividend on May 15, 2024 and the payment date for the dividend to be May 17, 2024. Merrimack expects to cease trading on NASDAQ on May 15, 2024. In the event that the Company’s stockholders do not approve the Plan of Dissolution, Merrimack will withdraw its notice to NASDAQ of its intent to delist Merrimack’s Common Stock and regular trading of its Common Stock will thereafter continue until further notice.

IMPORTANT ADDITIONAL INFORMATION AND WHERE TO FIND IT

In connection with the proposed liquidation and Dissolution of the Company (the “Dissolution”) and the Plan of Dissolution, the Company filed a definitive proxy statement (the “Proxy Statement”) with the Securities and Exchange Commission (the “SEC”) on March 21, 2024. BEFORE MAKING ANY VOTING DECISION, INVESTORS AND SECURITY HOLDERS ARE URGED TO READ THE DEFINITIVE PROXY STATEMENT, ANY AMENDMENTS OR SUPPLEMENTS THERETO, ANY OTHER SOLICITING MATERIALS AND ANY OTHER DOCUMENTS TO BE FILED WITH THE SEC IN CONNECTION WITH THE PROPOSED DISSOLUTION, THE PLAN OF DISSOLUTION AND RELATED MATTERS, AND/OR INCORPORATED BY REFERENCE IN THE PROXY STATEMENT WHEN THEY BECOME AVAILABLE BECAUSE THEY CONTAIN OR WILL CONTAIN IMPORTANT INFORMATION ABOUT MERRIMACK PHARMACEUTICALS, INC., THE PROPOSED DISSOLUTION, THE PLAN OF DISSOLUTION AND RELATED MATTERS. Stockholders may obtain a free copy of the Proxy Statement and the other relevant materials (when they become available), and any other documents filed by the Company with the SEC, at the SEC’s website at http://www.sec.gov or on the “Investors” section of the Company’s website at www.merrimack.com.