Lead CF Drug Fails Phase 2a, Sionna Shares Crash 90% Premarket
SION is trading near its 52-week low of $16.87 (68% below the low).
Summary
Sionna's lead cystic fibrosis drug, SION-719, failed its Phase 2a proof-of-concept trial, missing the key activity endpoint. The company cited higher-than-expected variability in sweat chloride levels as a potential confounder. Shares collapsed nearly 90% in premarket trading to $5.27, wiping out most of the company's market value. This follows the 10-Q filed August 6th that had guided cash runway into 2028 and flagged two key data readouts this summer — one of which has now failed. The company is evaluating next steps for the SION-451 dual combination, but the lead program is terminated. With a $250M ATM in place but unused, and a market cap now around $230M, the pipeline is severely de-risked to the downside.
Updates
· Benzinga — Sionna shares closed down 92% at $4.86, and the company is discontinuing the SION-719 program entirely.
At the time of this announcement, SION was trading at $5.34 on NASDAQ in the Life Sciences sector, with a market capitalization of approximately $2.3B. The 52-week trading range was $16.87 to $54.97. This news item was assessed with negative market sentiment and an importance score of 10 out of 10. Source: Dow Jones Newswires.