Cambridge drug discovery business Mission Therapeutics has raised $15 million in equity investment in a round led by existing backer Pfizer Ventures, the venture capital arm of Wall Street-quoted Pfizer Inc.

Perhaps more importantly looking to the long term, the companies have also expanded their relationship. 

Mission focuses on selectively inhibiting deubiquitylating enzymes (DUBs) and the partners have extended the alliance to include an evaluation and option agreement for DUB target validation.

Pfizer Ventures has been an investor in Mission Therapeutics since 2013. Today it has invested a super pro rata amount. 

All other existing investors within Mission joined the round on a pro rata basis. No further financial details have been disclosed.

The new capital will support development of Mission’s world-leading DUB platform, as well as growth of its pipeline of DUB inhibitor programmes.

DUBs have attracted significant interest as potential drug targets. Playing an integral role in protein homeostasis, this large family of enzymes is involved in diverse cellular processes and many disease pathologies.

Under the terms of the evaluation and option agreement, Pfizer will access specific DUB inhibitors from Mission’s platform and test these compounds in phenotypic screens to validate promising drug targets. Pfizer will then have the option to negotiate target exclusivity for each of the DUBs of interest. The agreement does not include any of Mission’s own lead DUB programs, such as USP30.

Dr Denis Patrick, managing partner of Pfizer Ventures and a member of Mission’s board said: “Since our initial investment in Mission seven years ago, the company has grown tremendously and the depth of its scientific expertise and capability has grown alongside it. 

“We are proud to expand our relationship with the company and our scientists are looking forward to a successful collaboration in this important area of research.”

Dr Anker Lundemose, CEO of Mission Therapeutics added: “We are pleased to expand our relationship with Pfizer, one of the world’s premier biopharmaceutical companies. 

“We have benefitted from the valuable contributions of Dr Patrick as a member of our board and look forward to working with the wider Pfizer team.”