Milestone resubmits new drug application while Aldeyra readies similar 2nd-chance filing

Milestone Pharmaceuticals has resubmitted a new drug application to the FDA, with Aldeyra Therapeutics readying a similar ask for the second half of the year.

The regulatory updates disclosed Thursday offer a glimmer of hope to two biotechs trying to rebound from previous NDA misses. Milestone is the first to give it another go, resubmitting an application for etripamil, a self-administered nasal spray to treat paroxysmal supraventricular tachycardia (PSVT), a type of abnormal heart rhythm.

The biotech received a refuse-to-file letter in late December 2023 after regulators deemed the application insufficient for review and asked for additional information on the timing of side effect data. The company said at the time that the FDA didn’t express concern about the side effects themselves. 

“We believe we have addressed all the issues raised in the Refusal to File letter and look forward to working with the agency as it reviews our application,” President and CEO Joseph Oliveto said in Thursday’s release.

The resubmission is made more critical by its impact on etripamil’s second and larger indication, atrial fifibrillation with rapid ventricular response. Milestone said in a fourth-quarter earnings update that the FDA reiterated prior guidance that should the spray be approved to treat PSVT, a single atrial fibrillation study should suffice as part of a supplemental NDA to expand the indication. Milestone expects to finalize the study protocol for a registrational trial by the middle of 2024.

Aldeyra is not too far behind, expecting to resubmit an application for reproxalap after being rejected in November 2023. It was hardly a surprise after the company said a month earlier that the move was anticipated

Aldeyra plans to initiate a dry eye chamber trial in the first half of 2024, which, if successful, would form the basis for a resubmitted NDA in the second half. The biotech also plans to conduct another trial at a separate dry eye chamber plus a six-week field trial in parallel with the pivotal study “as part of a comprehensive strategy designed to account for disease heterogeneity and potential differences in clinical sites and environment,” according to a release. 

Aldeyra reiterated that its $142.8 million in cash on hand is enough to last “beyond 2026.”