GSK Acquires TESARO for $5.1 Billion

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The acquisition of biopharmaceutical company TESARO is expected to strengthen GSK’s oncology pipeline and commercial footprint.

On Jan. 22, 2019, GlaxoSmithKline (GSK) announced that it acquired biopharmaceutical company TESARO for an aggregate cash consideration of approximately $5.1 billion.

The transaction was a cash tender offer by GSK’s indirect wholly owned subsidiary, Adriatic Acquisition Corporation, to purchase all of the issued and outstanding shares of TESARO common stock for $75.00 per share net to the holder in cash.

Announced in December 2018, the acquisition is expected to strengthen GSK’s pharmaceutical business, specifically its oncology pipeline and commercial capability.

TESARO is an oncology-focused, commercial-stage biopharmaceutical company based in Waltham, MA, with a major marketed product, Zejula (niraparib), an oral poly ADP ribose polymerase (PARP) inhibitor currently approved for use in ovarian cancer. The drug made $108.8 million in 2017 sales. 2018 sales data are not available at this time.

GSK states that PARP inhibitors are transforming the treatment of ovarian cancer, where they demonstrate marked clinical benefit in patients with and without germline mutations in a BRCA gene (gBRCA). Zejula is currently approved in the United States and Europe as a treatment for adult patients with recurrent ovarian cancer who are in response to platinum-based chemotherapy, regardless of BRCA mutation or biomarker status.


GSK also believes PARP inhibitors offer opportunities for treating multiple cancer types. In addition to ovarian cancer, Zejula is currently being investigated for use as a possible treatment in lung, breast, and prostate cancer, both as a monotherapy and in combination with other medicines, including with TESARO’s anti-PD-1 antibody, dostarlimab (formerly known as TSR-042). In addition to Zejula and dostarlimab, TESARO has several oncology assets in its pipeline, including antibodies directed against TIM-3 and LAG-3 targets.

“This new partnership between TESARO and GSK marks an important milestone in advancing our mission of developing transformative therapies for individuals living with cancer,” said Dr. Mary Lynne Hedley, president and COO, TESARO, in a company press release. “Together with GSK, we can accelerate and further advance TESARO’s development and commercialization initiatives and, ultimately provide more time for more patients.” 

Source: GlaxoSmithKline