GlaxoSmithKline, Tesaro agree to $5.1 billion deal

Emma Walmsley of GlaxoSmithKline poses in this undated photograph released in London.Reuters via handout

• GlaxoSmithKline just agreed to acquire the cancer drugmaker Tesaro for $5.1 billion in a bid to bulk up its cancer pipeline. 
• Tesaro makes a drug called Zejula, which is used to treat ovarian cancer. 
• GSK has been working to refresh its research-and-development strategy — in July it made a $300 million investment in the consumer-genetics company 23andMe. 

GlaxoSmithKline is getting deeper into cancer drug development. 

On Monday, the UK-based pharma giant said it had agreed to acquire Tesaro, a cancer drugmaker with a treatment for ovarian cancer, for $5.1 billion. 

Tesaro was up 60% on the news before markets opened Monday while GSK was down 6%. 

GSK has been working to refresh its research-and-development strategy. In 2017, GSK brought on Hal Barron, a former Genentech and Calico executive, as its chief scientific officer and president of R&D.

As part of that, the company made a $300 million investment in the consumer-genetics company 23andme. GSK also said in July that it planned to focus its research efforts on developing new treatments that act on the body’s immune system. 

Read more: Why pharma giant GSK just made a $300 million bet on 23andMe’s approach to finding new medicines

“Our strong belief is that PARP inhibitors are important medicines that have been under appreciated in terms of the impact they can have on cancer patients,” Barron said said in a press release. “We are optimistic that Zejula will demonstrate benefit in patients with ovarian cancer beyond those who are BRCA-positive as front-line treatment.”

Tesaro makes a cancer drug called Zejula, which is used to treat ovarian cancer. 

Zejula is a pill that’s taken once a day, and it’s part of a group of cancer drugs called PARP inhibitors. Essentially, they block a particular enzyme that’s used by our cells to repair DNA. In certain kinds of cancer that repair system is broken, allowing cancer cells to thrive, so blocking it is critical.

Zejula isn’t the only PARP inhibitor out there: Pfizer acquired one in its deal for Medivation, Clovis Oncology makes Rubraca, and AstraZeneca has Lynparza