GOSS: Management Optimistic About Topline Results -- LEVI & KORSINSKY, LLP Investigates After Trial Fails

Gossamer Bio CEO Expressed Optimism About PROSERA Trial Outcome; the Study Missed Its Primary Endpoint Months Later

NEW YORK, March 18, 2026 /PRNewswire/ -- Gossamer Bio, Inc. (NASDAQ: GOSS) shareholders suffered significant losses when the Company disclosed that its Phase 3 PROSERA study of seralutinib missed its primary 6-minute walk distance endpoint in pulmonary arterial hypertension. In May 2025, CEO Faheem Hasnain told investors the Company was "more optimistic than ever about the likelihood of achieving positive results." If you lost money on GOSS shares, submit your information now to discuss your legal rights. You may also contact Joseph E. Levi, Esq. via email at [email protected] or by telephone at (212) 363-7500.

During the Q1 2025 earnings call on May 15, 2025, CEO Hasnain stated: "The baseline characteristics of the patients enrolled thus far are precisely what we have targeted." He further claimed the Company had "over 90% power given the sample size" and that the enrolled patient population indicated "a materially more severe population than the TORREY study." He told investors to expect top-line results in February 2026.

When those results arrived, PROSERA had missed its primary endpoint -- the study's p-value of 0.032 failed to meet the prespecified significance threshold of 0.025. Levi & Korsinsky, LLP is investigating whether Gossamer Bio's prior statements to investors about trial confidence, statistical power, and patient baseline characteristics were accurate when made.

Shareholders who purchased GOSS and suffered a loss are encouraged to click here to submit their information. You may also contact Joseph E. Levi, Esq. via email at [email protected] or by telephone at (212) 363-7500.

WHY LEVI & KORSINSKY -- Ranked in ISS Securities Class Action Services' Top 50 Report for seven consecutive years, Levi & Korsinsky, LLP is a nationally recognized leader in shareholder rights litigation. With a team of over 70 professionals, the firm has recovered hundreds of millions of dollars for investors.

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