After Astra’s PARP1-selective move, Gilead buys in

After Astrazeneca and Merck & Co turned Parp blockade into a viable oncology strategy, courtesy of Lynparza, the UK group started talking up a PARP1-selective inhibitor, AZD5305, which apparently is more tolerable. Gilead today appeared to buy into this story, acquiring Xinthera, a private biotech developing three small-molecule PARP1 inhibitors. That said, the acquired assets are still preclinical, and the deal carries an undemanding price tag: Gilead’s disclosure of its EPS impact hints at a $170m valuation. Xinthera had so far raised $80m from private investors, most recently at a $150m valuation. Is enthusiasm warranted? At last year’s AACR AZD5305 yielded a 25% ORR among 40 patients, with reduced nausea and vomiting versus Lynparza, Zejula, Talzenna and Rubraca on a cross-trial basis. Separately, Astra is undertaking clinical development of AZD9574, a brain-penetrant Parp1 inhibitor, a property shared by Xinthera’s XIN6301, Valo’s OPAL-0001 and Nerviano/Merck KGaA’s NMS-293. Nerviano and German Merck struck a deal covering NMS-293 last year, and growing interest in the PARP1-selective inhibition should back their work also.

PARP1-selective inhibitors

Note: *said to be CNS penetrant.