MILESTONE PHARMACEUTICALS

Milestone Pharmaceuticals will present poster data on etripamil's efficacy, safety, and tolerability for self-administered treatment of paroxysmal supraventricular tachycardia at AHA Scientific Sessions 2025.

DelveInsight's 2025 pipeline report reveals over 12 active companies developing 15+ novel atrial fibrillation therapies, with promising candidates including Abelacimab, Etripamil, and THRV-1268 advancing through clinical trials.

• The FDA has issued a Complete Response Letter for Milestone Pharmaceuticals' Cardamyst (etripamil) nasal spray, citing chemistry, manufacturing, and controls issues rather than safety or efficacy concerns. • TD Cowen downgraded Milestone Pharmaceuticals from Buy to Hold and suspended its price target, citing regulatory uncertainty and the company's limited capital reserves of $69.7 million. • Milestone expects results from ongoing nitrosamine impurity assays in April and plans a Type A meeting with the FDA in May or June to determine the path forward for resubmission.

• The FDA has rejected Milestone Pharmaceuticals' nasal spray Cardamyst for paroxysmal supraventricular tachycardia, citing chemistry, manufacturing and controls issues, causing company shares to plummet over 60%. • Cardamyst, a novel calcium channel blocker, showed promising Phase III results being "twice as effective and three times as fast as placebo" in normalizing heart rhythm for the 2 million Americans affected by PSVT. • Despite the setback, Milestone plans to request a Type A meeting with the FDA to address concerns, while continuing development of Cardamyst for atrial fibrillation in Phase II trials.

Milestone Pharmaceuticals received a Notice of Allowance from the USPTO for a new patent covering the repeat dose regimen of etripamil nasal spray, extending potential IP protection to July 2042.

• Ji Xing Pharmaceuticals' Phase III trial of etripamil nasal spray met its primary endpoint, showing a statistically significant conversion to normal heart rhythm within 30 minutes compared to placebo. • The trial, conducted across 40 hospitals in China, demonstrated that 40.5% of patients converted to sinus rhythm with etripamil versus 15.9% with placebo. • Secondary efficacy endpoints were also met, with treatment-emergent adverse events being comparable between the etripamil and placebo groups, and no serious adverse events reported. • Ji Xing Pharmaceuticals plans to engage with regulatory authorities to advance the new drug application for etripamil, aiming to provide a self-managed treatment option for PSVT patients.

The FDA has accepted Milestone Pharmaceuticals' NDA for Cardamyst (etripamil) nasal spray, a potential treatment for paroxysmal supraventricular tachycardia (PSVT).

• Milestone Pharmaceuticals has resubmitted its New Drug Application (NDA) to the FDA for etripamil nasal spray, a potential treatment for paroxysmal supraventricular tachycardia (PSVT). • The resubmission addresses issues raised in a previous Refusal to File letter from the FDA, incorporating restructured data sets and reformatted data files. • Etripamil is designed as a self-administered rapid response therapy, offering patients a new option for on-demand management of PSVT episodes. • If approved, etripamil nasal spray could provide a valuable treatment option for the estimated two million people in the U.S. diagnosed with PSVT.