Why is Gossamer Bio facing a securities class action lawsuit?

Investors allege Gossamer made misleading statements about the design and reliability of its Phase 3 PROSERA clinical study.

What is the PROSERA study mentioned in the Gossamer lawsuit?

The PROSERA study is a Phase 3 clinical trial evaluating a Gossamer drug candidate, central to the company’s development pipeline.

What problems are alleged with the PROSERA study design?

The complaint claims the study did not adequately control for placebo response, particularly at Latin American testing sites.

Why is placebo response important in clinical trials?

A high placebo response can make it harder to measure a drug’s true effectiveness, potentially skewing trial results.

What are investors alleging Gossamer failed to disclose?

Plaintiffs claim the company did not fully disclose flaws in the study design that could affect data reliability.

How could flawed trial design affect Gossamer’s drug approval prospects?

Regulators may question the validity of results, potentially delaying approval or requiring additional studies.

Why are clinical trial disclosures important for biotech investors?

Trial design and results directly impact regulatory approval and future revenue, making transparency critical.

What does it mean that trial reliability was overstated?

Investors allege the company presented the study as more robust and reliable than it actually was.

How could these allegations affect Gossamer’s stock price?

Concerns about trial design and data integrity may reduce confidence in the drug’s prospects, impacting valuation.

Who may qualify to participate in the Gossamer class action?

Investors who purchased Gossamer securities between June 16, 2025 and February 20, 2026 may be eligible if they suffered losses.

What is the deadline to seek lead plaintiff status in the Gossamer lawsuit?

Investors seeking appointment as lead plaintiff must file a motion by June 1, 2026.

What is a securities class action lawsuit?

A securities class action allows investors to pursue claims collectively against a company for misleading statements or omissions.

What does the term “class period” mean in a securities lawsuit?

The class period is the timeframe during which alleged misleading statements occurred and investors may have purchased shares.

What is a lead plaintiff in a securities class action?

The lead plaintiff is the investor selected by the court to represent the interests of all shareholders in the case.

How do investors receive compensation from a securities class action settlement?

If a settlement is reached, investors submit claim forms documenting their trades to receive a portion of the settlement fund.

Gossamer Bio, Inc. - Faruqi & Faruqi LLP

Gossamer Bio, Inc.

Join Action

Case Details

Ticker GOSS

Class Period 06/16/2025 - 02/20/2026

Lead Plaintiff Deadline 06/01/2026

Days Left to Seek Plaintiff

If you are a Gossamer Bio investor who suffered a loss and would like to learn more, you can provide your information below:

If you purchased or acquired securities in Gossamer between June 16, 2025 and February 20, 2026 and would like to discuss your legal rights, call Faruqi & Faruqi partner Josh Wilson directly at 877-247-4292 or 212-983-9330 (Ext. 1310).

Faruqi & Faruqi, LLP, a leading national securities law firm, is investigating potential claims against Gossamer Bio, Inc. (“Gossamer” or the “Company”) (NASDAQ: GOSS) and reminds investors of the June 1, 2026 deadline to seek the role of lead plaintiff in a federal securities class action that has been filed against the Company.

As detailed below, the complaint alleges that the Company and its executives violated federal securities laws by making false and/or misleading statements and/or failing to disclose that the study design for the Company’s Phase 3 PROSERA study, particularly, controlling for the placebo response at the Latin American testing sites.

Lead Plaintiff Deadline: June 1, 2026

Call Partner Josh Wilson at 877-247-4292 or 212-983-9330 (Ext. 1310)
Or submit your information below to learn about your rights.

Join Action

Gossamer Bio, Inc.

Monetary Losses ($) *

Website URL

First Name *

Last Name *

Telephone *

Email *

Street Address

City

State

Zip Code

Purchases

1	Purchases Options Price per Share Date # of Shares Principal Amount Amount Paid Series or Cusip # of Contracts Price per Contract Exercise Price Expiration Date
1	Purchases Options Price per Share Date # of Shares Principal Amount Amount Paid Series or Cusip # of Contracts Price per Contract Exercise Price Expiration Date

Add Row

Sales

1	Sales Options Price per Share Date # of Shares Principal Amount Amount Paid Series or Cusip # of Contracts Price per Contract Exercise Price Expiration Date
1	Sales Options Price per Share Date # of Shares Principal Amount Amount Paid Series or Cusip # of Contracts Price per Contract Exercise Price Expiration Date

Add Row

Upload your trades here:

Accepted file types: xls, xlsx, doc, docx, pdf, jpg, jpeg, png, Max. file size: 50 MB, Max. files: 5.
You may redact account numbers from your uploaded documents.

File name:

File size:

Select File

Does not establish an attorney-client relationship *

By clicking this box, I acknowledge that this form is not intended to and does not establish an attorney-client relationship between myself and Faruqi & Faruqi LLP, and that the submission or receipt of information via this form, e-mail or telephone does not create an attorney-client relationship.

Case

Users to notify