GlaxoSmithKline to buy oncology-focused Tesaro for $5.1bn

GlaxoSmithKline has agreed to buy US-based oncology-focused pharmaceutical group Tesaro Inc for around $5.1bn (£4bn).

Under the terms of the deal, which has been unanimously approved by Tesaro's board, shareholders will receive $75 per share in cash, which represents a premium of 110% to the 30-day volume-weighted average price.

Glaxo expects the deal - due to complete in the first quarter of next year - to accelerate the build of its pipeline and commercial capability in oncology.

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.

Hal Barron, chief scientific officer and president of research and development at GSK, said: "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. We are optimistic that Zejula will demonstrate benefit in patients with ovarian cancer beyond those who are BRCA-positive as front-line treatment.

"We are also very excited that through this transaction, we will have the opportunity to work with an outstanding Boston-based oncology group with deep clinical development expertise and together we will explore Zejula’s efficacy beyond ovarian cancer into multiple tumour types to help many more patients."

Zejula’s revenues in its current approved indication as second-line maintenance treatment for ovarian cancer were $166m for the nine months ended 30 September 2018.

Glaxo said the acquisition and associated R&D and commercial investments will impact adjusted earnings per share for the first two years by mid to high single digit percentages, reducing thereafter with the acquisition expected to start to be accretive to adjusted EPS by 2022.

The company's guidance for full-year 2018 adjusted EPS growth remains unchanged at 8 to 10% at constant exchange rates.

At 1245 GMT, GSK shares were down 4% to 1,557p and Tesaro shares were up a whopping 60% in pre-market trade at $73.78.

Liberum said: "Clearly GSK needs to bolster its pipeline and Tesaro certainly does that. However, Zejula in its existing indication is struggling to compete with Astra/Merck's Lynparza while its PD1 is well behind other competitors. At this point Tesaro looks to be second best in the PARP space and while this can be turned around with expansion in other indications, we have limited evidence thus far that this will be the case.

"Moreover, we are not sure where the synergies are with GSK. A Roche acquisition of Tesaro may have made some strategic sense given it lacks a PARP but has an established PDL1 therapy. For GSK we see less clear rationale for the deal but await more detail on the conference call later today."