British drugmaker GlaxoSmithKline plans to purchase a US-based manufacturer of drugs for cancers, the two companies said.
GSK and Tesaro said Monday that they had reached an agreement under which the London-based pharmaceutical giant will acquire Waltham, Massachusetts-based Tesaro for $5.1 billion, or $75 per share, representing a 110 percent premium over Tesaro’s 30-day volume-weighted aerage price of $35.67.
Tesaro’s only marketed product is Zejula (niraparib), a PARP inhibitor approved for the maintenance treatment of recurrent ovarian, fallopian tube or primary peritoneal cancer, following a response to treatment with platinum-based chemotherapy. Its nearest competitors are AstraZeneca’s Lynparza (olaparib), the first Food and Drug Administration-approved PARP inhibitor, and Clovis Oncology’s Rubraca (rucaparib). Approved in March 2017, Zejula was the first PARP inhibitor to be approved without the requirement that patients carry BRCA mutations.
Following the news, Tesaro’s shares were up nearly 60 percent on the Nasdaq in Tuesday morning trading. Clovis Oncology’s shares were up nearly 20 percent.
“The acquisition of Tesaro will strengthen our pharmaceuticals business by accelerating the build of our oncology pipeline and commercial footprint, along with providing access to new scientific capabilities,” GSK CEO Emma Walmsley said in a statement.
Zejula has seen its sales increase significantly since last year. Sales for the nine months ended Sept. 30 were $165.9 million, compared with $65.3 million for the same period in 2017. Rubraca, which won accelerated approval in December 2016, had sales of $65 million for the first nine months of 2018, compared with $38.5 million in the first nine months of 2017. Lynparza’s sales in the first nine months of 2018 were $438 million globally and $233 million in the US.
In addition to Zejula, Tesaro also has several immuno-oncology drugs in clinical development. These include TSR-042, an anti-PD-1 monoclonal antibody in Phase I development for microsatellite instability-high tumors and metastatic endometrial cancer; the anti-TIM-3 antibody TSR-022; and the anti-LAG-3 antibody TSR-033. Merck & Co.’s PD-1 inhibitor Keytruda (pembrolizumab) received accelerated FDA approval last year for MSI-H cancers regardless of where they occur in the body. TIM-3 and LAG-3 are immune checkpoints whose targeting, it is hoped, can release the “brakes” on the immune system that prevent T cells from killing cancer cells.
Phase I data on TSR-042 and TSR-022 presented at the Society for Immunotherapy of Cancer conference last month showed early efficacy signals for the drugs.
Photo: Kritchanut, Getty Images
