The FDA has thrown a wrench in Regeneron’s plans to challenge Johnson & Johnson and Pfizer in a blood cancer market, hitting the Big Biotech with a complete response letter over issues at a third-party manufacturer.
Regeneron filed for approval of its BCMAxCD3 bispecific antibody linvoseltamab on the strength of phase 1/2 data in relapsed or refractory multiple myeloma. The FDA accepted the application for priority review and set an Aug. 22 decision date. However, at the start of August, Regeneron revealed that the decision was likely to be delayed beyond the PDUFA date over a manufacturing matter.
Tuesday evening, Regeneron said the FDA issued a complete response letter in relation to findings from a preapproval inspection at a third-party fill/finish manufacturer for another company’s product candidate.
The third-party manufacturer told Regeneron it believes the FDA’s findings have been resolved and it is awaiting the reinspection that could close the case. Regeneron made similar comments on its earnings call at the start of August, suggesting that it is at least several weeks since the manufacturer made the requested fixes. A reinspection is expected in “the coming months,” according to Regeneron.
On the earnings call, Regeneron CEO Leonard Schleifer, M.D., Ph.D., called rejections related to manufacturing issues and third-party fill-finish facilities “an industrywide kind of issue,” adding that “I think the FDA is, in fact, planning some sort of public hearing on these sorts of things.”
Regeneron’s filing for approval of Eylea HD was rejected last year over inspection findings at a Catalent facility. The company won approval for Eylea HD seven weeks after disclosing the rejection and is now working with its third-party manufacturer and the FDA to swiftly resolve the setback to linvoseltamab.
The bispecific, which is still under review at the European Medicines Agency, has generated data that suggest it may be able to make a mark on the multiple myeloma market despite ceding a head start to rival products.
At 71%, the overall response rate for linvoseltamab is higher than results for J&J’s Tecvayli and Pfizer’s Elrexfio, although that could reflect differences between the trials rather than the efficacy of the drugs. The complete response rate for linvoseltamab, 46%, is competitive, too.
Beyond efficacy, Regeneron has identified the rate of cytokine release syndrome, plus the speed at which the adverse event emerges, as a point of differentiation that could favor linvoseltamab. People receiving linvoseltamab may need to spend fewer days in hospital than their counterparts on rival drugs, too, and Regeneron has studied the potential to reduce the frequency of dosing.