Vanflyta’s path to the US could be tougher than in Japan

It is not all that common for Japan to approve a drug before it gets a US green light, and the case of Daiichi Sankyo’s quizartinib looks particularly interesting. The acute myelogenous leukaemia product, now trademarked Vanflyta, got the nod in Japan having earlier suffered an advisory panel vote against its approval in the US, on the grounds that its benefit did not outweigh the risk. The US FDA is notoriously lenient towards cancer drugs, so approval is still possible by Vanflyta’s August 25 PDUFA date, though this is not guaranteed. One consideration for Daiichi is commercial: as a Flt3 inhibitor Venflyta would, in the relapsed Flt3-mutated AML setting, compete against two similarly acting US-approved drugs: Novartis’s Rydapt and Astellas’s Xospata. Only the latter has already been approved in Japan. Separately, Roche’s Rozlytrek (entrectinib), acquired through the Swiss group’s purchase of Ignyta, was approved in Japan today for treating NTRK fusion-positive solid tumours, also before a US FDA verdict. In Rozlytrek’s case US approval, due by August 18, is a near certainty.