GSK’s TESARO Initiates Litigation Against AnaptysBio

GSK plc (LON: GSK) announced Friday that it is embroiled in a legal dispute initiated by its subsidiary, TESARO, against AnaptysBio, Inc., regarding the oncology treatment Jemperli (dostarlimab).

The litigation, filed in the Delaware Chancery Court, alleges that AnaptysBio has materially breached its existing license agreement, potentially allowing TESARO to terminate the agreement, secure a perpetual license to dostarlimab, and significantly reduce royalty and milestone payments.

TESARO's legal action comes in response to AnaptysBio's claims that TESARO has failed to meet certain obligations outlined in the March 2014 license agreement, with AnaptysBio threatening to revoke TESARO's license for dostarlimab.

GSK and TESARO are vehemently refuting these allegations, asserting they are without merit. The outcome of this legal battle could have substantial financial implications for GSK, impacting future revenue streams and the potential for further development of dostarlimab across various cancer types.

Jemperli, currently approved in over 35 countries, is a key growth driver for GSK, particularly in the treatment of certain endometrial cancers, the most common gynecologic cancer in the United States.

Recent reports from GSK and TESARO highlight significant growth in Jemperli sales, fueled by label expansions in both the US and EU markets. The company has invested heavily in clinical trials to explore dostarlimab's efficacy in treating other cancers, including rectal, colon, and head and neck cancers.