TESARO

A significant milestone in the company's history was its acquisition by GSK, a deal announced on December 3, 2018, and completed on January 22, 2019, for an aggregate cash consideration of approximately $5.1 billion. This acquisition was a strategic move for GSK to significantly strengthen its pharmaceuticals business by accelerating its oncology pipeline and commercial capabilities. Prior to the acquisition, TESARO had already made notable progress, including the FDA approval of its first commercial product, Varubi, in October 2015, and the approval of Zejula (niraparib) for ovarian cancer in March 2017.

The company's primary commercial product is Zejula (niraparib), an oral poly ADP-ribose polymerase (PARP) inhibitor. PARP inhibitors are a class of drugs that have transformed the treatment of ovarian cancer, showing clinical benefit in patients both with and without BRCA gene mutations. Zejula is approved in the U.S. and Europe for adult patients with recurrent ovarian cancer who are responding to platinum-based chemotherapy. The product's mechanism involves concentrating in the tumor relative to plasma, which results in durable inhibition of PARP 1/2 and a persistent anti-tumor effect. Beyond its application in ovarian cancer, Zejula is also under investigation for treating lung, breast, and prostate cancer, both as a monotherapy and in combination with other drugs.

TESARO's development pipeline extends beyond Zejula. It includes dostarlimab (formerly TSR-042), an anti-PD-1 antibody, and other antibodies targeting TIM-3 and LAG-3. Dostarlimab works by blocking the PD-1 protein on immune T-cells, preventing tumors from evading the immune system. The company has also developed Rolapitant, an NK-1 receptor antagonist for preventing chemotherapy-induced nausea and vomiting. This robust pipeline, combined with its established commercial products, positions TESARO as a significant contributor to the oncology market, serving cancer patients and the broader cancer community.