Securities Fraud Investigation Into Sionna Therapeutics, Inc. (SION) Announced – Shareholders Who Lost Money Urged to Contact The Law Offices of Frank R. Cruz

LOS ANGELES--(BUSINESS WIRE)--The Law Offices of Frank R. Cruz announces an investigation of Sionna Therapeutics, Inc. (“Sionna” or the “Company”) (NASDAQ: SION) on behalf of investors concerning the Company’s possible violations of federal securities laws.

IF YOU ARE AN INVESTOR WHO LOST MONEY ON SIONNA THERAPEUTICS, INC. (SION), CLICK HERE TO INQUIRE ABOUT POTENTIALLY PURSUING A CLAIM TO RECOVER YOUR LOSS.

What Is the Investigation About?

On August 10, 2026, Sionna reported topline data from its PreciSION CF Phase 2a trial and provided a corporate update. Among other items, Sionna announced a primary endpoint miss and that the Company will not advance SION-719 as an add-on to standard of care.

On this news, Sionna's stock fell $46.54, or 91.2% per share, to close at $4.10 per share on August 10, 2026, thereby injuring investors.

Contact Us to Participate or Learn More:

If you purchased Sionna Therapeutics, Inc. securities, have information or would like to learn more about these claims, or have any questions concerning this announcement or your rights or interests with respect to these matters, please contact us:

The Law Offices of Frank R. Cruz
2121 Avenue of the Stars, Suite 800
Century City, California 90067
Call us at: 310-914-5007
Email us at: [e-mail]
Visit our website at: www.frankcruzlaw.com.
Follow us for updates on Twitter at twitter.com/FRC_LAW.

If you inquire by email, please include your mailing address, telephone number, and number of shares purchased.

This press release may be considered Attorney Advertising in some jurisdictions under the applicable law and ethical rules.