Global biopharma giant GSK's subsidiary TESARO has sued its partner AnaptysBio, accusing the latter of committing a “material breach” of their license agreement for cancer drug Jemperli (dostarlimab).

The legal action against AnaptysBio has been initiated in Delaware Chancery Count in US.

In its complaint, TESARO argues AnaptysBio’s recent conduct violates the terms of the 2014 deal and gives TESARO the right to terminate the agreement, secure a perpetual and irrevocable license to Jemperli, and slash future royalty and milestone payments by 50%.

The move follows accusations from AnaptysBio that TESARO failed to meet certain obligations under the pact and that it intends to revoke TESARO’s licence. GSK and TESARO flatly reject those claims, calling them “entirely without merit".

GSK (GlaxoSmithKline), one of the world’s largest global biopharma companies, develops medicines and vaccines across areas like oncology and infectious disease. TESARO is an oncology-focused biotech company that GSK acquired in 2019.