GSK completes acquisition of oncology firm TESARO for approximately $5.1 billion

GSK plc announced on January 22, 2019, the completion of its acquisition of TESARO, Inc., an oncology-focused biopharmaceutical company based in Waltham, Massachusetts, for approximately $5.1 billion in cash. The transaction, initially announced on December 3, 2018, substantially strengthens GSK’s pharmaceutical business by accelerating the growth of its oncology pipeline and commercial operations.

TESARO's key asset is Zejula (niraparib), an oral PARP inhibitor approved for the treatment of ovarian cancer in the US and Europe. Zejula is indicated for adult patients with recurrent ovarian cancer who are in response to platinum-based chemotherapy. The drug has demonstrated significant clinical benefit, transforming treatment approaches for ovarian cancer, particularly in patients with and without BRCA gene mutations.

GSK plans to leverage TESARO’s expertise to expand Zejula’s application. Clinical trials are underway to evaluate Zejula as a first-line maintenance treatment for ovarian cancer in a broader patient population, including those without BRCA mutations. The company also sees potential for Zejula in treating other cancer types, such as lung, breast, and prostate cancer, both as a monotherapy and in combination with other treatments, including TESARO’s anti-PD-1 antibody, dostarlimab.

Beyond Zejula and dostarlimab, TESARO possesses additional oncology assets in its pipeline. "The acquisition of TESARO significantly strengthens our oncology pipeline and brings new scientific capabilities and expertise that will increase the pace and scale at which we can help patients living with cancer," stated Hal Barron, Chief Scientific Officer and President, R&D, GSK. Following the acquisition, TESARO’s shares ceased trading on NASDAQ.