GlaxoSmithKline (GSK) have completed a deal worth approximately $5.1bn in its acquisition of oncology-focused biopharmaceutical company Tesaro.

GSK have stated the merger will significantly boost its pharmaceutical portfolio as well as speed up the development of drugs in the field of oncology.

Tesaro’s most prominent product is Zejula (niraparib), an oral poly ADP ribose polymerase (PARP) inhibitor currently approved in the US and Europe for the treatment of ovarian cancer.

GSK have certified their belief that PARP inhibitors offer significant opportunities for use in treating multiple types of cancer as it is also being studied for use in lung, breast and prostate cancer.

Additionally, aside from Zejula, Tesaro has several oncology assets in its pipeline directed against PD-1, Tim-3 and LAG-3 targets.

Hal Barron, Chief Scientific Officer and President of R&D 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 benefits in patients with ovarian cancer beyond those who are BRCA-positive as front-line treatment.”