On Jan. 22, 2019, GlaxoSmithKline acquired TESARO based in Waltham, Massachusetts, for an aggregate cash consideration of approximately $5.1 billion.

TESARO is a commercial-stage biopharmaceutical company, with a major marketed product, Zejula (niraparib), an oral poly ADP ribose polymerase (PARP) inhibitor currently approved for use in ovarian cancer.