Merrimack Pharmaceuticals, Inc. is a biopharmaceutical company. The Company does not have any ongoing research or development activities and is seeking potential acquirers for its remaining preclinical and clinical assets. It is entitled to receive payments related to its sale of ONIVYDE to Ipsen S.A. and also its contingent payments related to its sale of MM-121 and MM-111 to Elevation Oncology, Inc. These payments are payable by Ipsen upon approval by the United States Food and Drug Administration (FDA) of Onivyde for certain additional clinical indications. ONIVYDE is approved by FDA to market as a first-line treatment of metastatic adenocarcinoma on the pancreas. It is also entitled to receive payments related to its sale of anti-HER3 programs to Elevation Oncology, Inc. The Company’s wholly owned subsidiaries include Merrimack Pharmaceuticals UK Limited and Merrimack Securities Corporation.