Sionna Therapeutics, Inc. Investigation Initiated: Levi & Korsinsky Investigates the Officers and Directors of Sionna Therapeutics, Inc. (SION)

NEW YORK CITY, NY / ACCESS Newswire / August 13, 2026 / Levi & Korsinsky notifies investors that it has commenced an investigation into Sionna Therapeutics, Inc. ("Sionna Therapeutics, Inc.") (NASDAQ:SION) concerning potential violations of the federal securities laws.

Sionna Therapeutics shares collapsed approximately 92% after the Company disclosed that its Phase 2a PreciSION CF trial of SION-719 failed to achieve its key activity endpoint and that it would not advance the candidate as an add-on therapy.

According to the Company's disclosure, SION-719 -- administered on top of standard of care -- produced a placebo-adjusted sweat chloride change of -1.0 mmol/L, with a p-value of 0.7. Sionna stated it would not advance SION-719 as an add-on therapy. The decline did not follow an apparent liquidity shortfall: Sionna reported approximately $268.3 million in cash, cash equivalents and marketable securities as of June 30, 2026, and a second-quarter net loss of $29.9 million.

Sionna's NBD1 stabilizer programs are central to its cystic fibrosis pipeline. The Company's FY2025 Form 10-K stated that it was "substantially dependent on the success of at least one of our nucleotide binding domain 1 ('NBD1') stabilizers." The investigation concerns whether SION investors received adequate disclosure regarding the Company's reliance on its NBD1 stabilizer programs and the risks associated with the SION-719 program.

If you suffered a loss on your Sionna Therapeutics, Inc. securities and would like to explore a potential recovery under the federal securities laws, Learn More About the Investigation or contact Joseph E. Levi, Esq. via email at [email protected] or call (212)363-7500 to speak to our team of experienced shareholder advocates.

WHY LEVI & KORSINSKY: Over the past 20 years, Levi & Korsinsky LLP has established itself as a nationally-recognized securities litigation firm that has secured hundreds of millions of dollars for aggrieved shareholders and built a track record of winning high-stakes cases. The firm has extensive expertise representing investors in complex securities litigation and a team of over 70 employees to serve our clients. For seven years in a row, Levi & Korsinsky has ranked in ISS Securities Class Action Services' Top 50 Report as one of the top securities litigation firms in the United States. Attorney Advertising. Prior results do not guarantee similar outcomes.

CONTACT:

Levi & Korsinsky, LLP

Joseph E. Levi, Esq.

Ed Korsinsky, Esq.

33 Whitehall Street, 27th Floor

New York, NY 10004

[email protected]

Tel: (212)363-7500

Fax: (212)363-7171

SOURCE: Levi & Korsinsky, LLP