{"entity":{"id":"merrimack-pharmaceuticals","kind":"company","name":"Merrimack Pharmaceuticals","aka":["Merrimack Pharmaceuticals, Inc.","Merrimack"],"tldr":"Merrimack was the Cambridge biotech behind liposomal irinotecan (Onivyde), approved for pancreatic cancer in 2015 and later sold to Ipsen; its antibody programmes failed and the company wound down.","summary":"Merrimack Pharmaceuticals, founded in 2000 in Cambridge, Massachusetts, developed MM-398, a liposomal formulation of irinotecan approved in 2015 as Onivyde for metastatic pancreatic cancer after gemcitabine (the NAPOLI-1 trial), which it sold to Ipsen in 2017. Its systems-biology antibody programmes, including the HER3 antibody seribantumab, did not reach approval, and the company later returned remaining assets to shareholders. Its phase 3 trials remain on ClinicalTrials.gov under Merrimack as lead sponsor.","asOf":"2026-09-11","links":[{"label":"Official website","url":"http://www.merrimackpharma.com"},{"label":"ClinicalTrials.gov: trials led by Merrimack Pharmaceuticals, Inc.","url":"https://clinicaltrials.gov/search?lead=Merrimack%20Pharmaceuticals%2C%20Inc."},{"label":"Wikidata","url":"https://www.wikidata.org/wiki/Q30287940"}],"tags":["ctgov-sponsor"],"related":[],"cancers":["pancreatic"],"sections":[],"technologies":[],"targets":[],"drugs":["irinotecan"],"companies":["ipsen"],"institutions":[],"pathways":[],"terms":["pivotal-trial","clinical-trial"],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"notes":[],"provenance":{"editedBy":"OnCo ingestion (ClinicalTrials.gov v2 + sponsor websites)","editedOn":"2026-09-11"},"hq":"Cambridge, MA","country":"US","companyType":"biotech","website":"http://www.merrimackpharma.com","founded":2000,"stage":"defunct","investors":[],"funding":[]},"route":"/companies/merrimack-pharmaceuticals/","neighbours":{"cancer":[{"id":"pancreatic","kind":"cancer","name":"Pancreatic ductal adenocarcinoma","route":"/cancers/pancreatic/"}],"drug":[{"id":"irinotecan","kind":"drug","name":"Irinotecan (and liposomal irinotecan)","route":"/drugs/irinotecan/"}],"company":[{"id":"ipsen","kind":"company","name":"Ipsen","route":"/companies/ipsen/"}],"term":[{"id":"clinical-trial","kind":"term","name":"Clinical trial","route":"/terms/clinical-trial/"},{"id":"pivotal-trial","kind":"term","name":"Pivotal (registrational) trial","route":"/terms/pivotal-trial/"}]}}