By Denny Jacob


Milestone Pharmaceuticals shares sank 24% to $2.20 in premarket trading after it received a refusal to file letter from the Food and Drug Administration.

The stock is down 27% on the year.

The biopharmaceutical company said it received the letter over its new drug application for its etripamil nasal spray to treat a type of abnormal heart rhythm. It added that the FDA determined that the application for etripamil nasal spray as a treatment of paroxysmal supraventricular tachycardia wasn't sufficiently complete to permit a substantive review based on a preliminary review.

The regulator requested clarification about the time of data recorded for adverse events in Phase 3 clinical trials, said Milestone.

Milestone said the FDA didn't express concerns about the nature or severity of adverse events. It will seek clarification and is planning a meeting with the FDA.


Write to Denny Jacob at denny.jacob@wsj.com


(END) Dow Jones Newswires

12-26-23 0839ET