Merrimack Pharmaceuticals, Inc., a biopharmaceutical company, engages in discovering, developing and commercializing medicines consisting of novel therapeutics paired with diagnostics for the treatment of cancer primarily in the United States. It offers ONIVYDE that is used for the treatment of patients with metastatic adenocarcinoma of the pancreas after disease progression following gemcitabine-based therapy. The company's therapeutic oncology candidates in clinical development include MM-398, which is in Phase II clinical trial for treating patients with previously untreated, metastatic pancreatic adenocarcinoma; Phase I clinical trial for the treatment of glioma, pediatric solid tumors, and gastrointestinal tumors; and Phase I clinical trial for treating metastatic breast cancer. Its therapeutic oncology candidates also include MM-302 for treating patients with ErbB2 (HER2) positive, locally advanced or metastatic breast cancer; and MM-121, which is in Phase II clinical trial for the treatment of patients with heregulin positive, advanced non-small cell lung cancer. In addition, the company's therapeutic oncology candidates consist of MM-141 that is in Phase II clinical trial for treating previously untreated metastatic pancreatic cancer patients who have high serum levels of free IGF-1; MM-151 that has completed a Phase I clinical trial for treating solid tumors; and MM-310 for treating solid tumors. Further, it is developing preclinical product candidates for solid tumor indications. The company has license and collaboration agreements with Baxter International Inc., Baxter Healthcare Corporation, and Baxter Healthcare SA; development, license, and supply agreement with Watson Laboratories, Inc.; sublicense and collaboration agreement with PharmaEngine, Inc.; collaboration agreements with Dyax Corp. and Adimab LLC,; and license agreement with University of California. The company was incorporated in 1993 and is headquartered in Cambridge, Massachusetts.