TD downgrades Milestone Pharmaceuticals, suspends target on Etripamil uncertainty

Investing.com -- TD Securities downgraded Milestone (WA:MMD) Pharmaceuticals (NASDAQ:MIST) to "Hold" and suspended its price target, citing regulatory uncertainty and commercialization challenges for its lead drug, etripamil, following a Complete Response Letter from the U.S. Food and Drug Administration.

The FDA issued a Complete Response Letter for MIST’s etripamil New Drug Application for paroxysmal supraventricular tachycardia (pSVT), citing chemistry, manufacturing, and controls issues.

While no safety or efficacy concerns were raised, the agency requested additional data on nitrosamine impurities based on new draft guidance published in September 2024, months after MIST had resubmitted its New Drug Application .

The FDA also flagged the need for an inspection at a third-party facility performing release testing, which changed ownership during the New Drug Application review.

MIST has ongoing assays to address the new impurity testing requirements, with results expected in April. A Type A meeting with the FDA is anticipated in May or June to determine the path forward.

TD expressed concerns over etripamil’s commercial viability, noting Milestone Pharmaceuticals' limited capital reserves. The company had $69.7 million in cash as of Q4 2024, which may not be sufficient to support an extended regulatory timeline.

TD suspended its price target and downgraded Milestone Pharmaceuticals, citing the uncertainty surrounding the FDA review process and the company’s financial position.

The firm noted that NDA resubmission timelines remain unclear, with additional concerns over the FDA’s operational efficiency.