GSK to Acquire TESARO for $5.1 Billion

TESARO, an oncology-focused company based in Waltham, and GlaxoSmithKline (GSK) have announced that they have entered into a definitive agreement by which GSK will acquire TESARO for an aggregate cash consideration of approximately $5.1 billion. The proposed transaction significantly strengthens GSK’s pharmaceutical business, accelerating the build of GSK’s pipeline and commercial capability in oncology.

TESARO is a commercial-stage biopharm, with a major marketed product, Zejula (niraparib), an oral poly ADP ribose polymerase (PARP) inhibitor currently approved for use in ovarian cancer. PARP inhibitors are transforming the treatment of ovarian cancer, notably demonstrating marked clinical benefit in patients with and without germline mutations in a BRCA gene. Zejula is currently approved in the US and Europe as a treatment for adult patients with recurrent ovarian cancer who are in response to platinum-based chemotherapy, regardless of BRCA mutation or biomarker status. In addition to Zejula, TESARO has several oncology assets in its pipeline.

Clinical trials to assess the use of Zejula in “all-comers” patient populations, as a monotherapy and in combinations, for the significantly larger opportunity of first line maintenance treatment of ovarian cancer are also underway. These ongoing trials are evaluating the potential benefit of Zejula in patients who carry BRCA mutations as well as the larger population of patients without these mutations whose tumors are HRD-positive and HRD-negative. Results from the first of these studies, PRIMA, are expected to be available in the second half of 2019.

GSK also believes PARP inhibitors offer significant opportunities for use in the treatment of multiple cancer types. In addition to ovarian cancer, Zejula is currently being investigated for use as a possible treatment in lung, breast and prostate cancer, both as a monotherapy and in combination with other medicines, including with TESARO’s own anti-PD-1 antibody.

Zejula’s revenues in its current approved indication as second-line maintenance treatment for ovarian cancer were $166 million for the nine months ended 30 September, 2018. (Source: TESARO Website, 03 December, 2018)

To read more about PARP inhibitors, click here. https://www.ispeboston.org/parp-inhibitors-may-offer-new-treatment-options-for-cancer-patients/