Gossamer Bio Faces Class Action Lawsuit Over Phase 3 Study Results
Written by Emily J. Thompson, Senior Investment Analyst
Updated: 34 minutes ago
0mins
Source: Globenewswire
- Class Action Initiated: Berger Montague PC has announced a class action lawsuit against Gossamer Bio on behalf of investors who purchased shares between June 16, 2025, and February 20, 2026, indicating significant investor dissatisfaction with the company's transparency.
- Clinical Trial Failure: Gossamer's PROSERA study results, announced on February 23, 2026, failed to meet the primary endpoint of improved six-minute walk distance (6MWD), leading to a substantial decline in investor confidence regarding the company's future prospects.
- Stock Price Plummet: Following the announcement, Gossamer's stock price dropped from $2.13 per share on February 20, 2026, to $0.42 per share on February 23, 2026, representing a loss of over 80% in a single day, reflecting market pessimism about its clinical outlook.
- Investor Rights Affected: Investors must apply by June 1, 2026, to be appointed as lead plaintiffs in the class action, demonstrating strong opposition to the company's failure to adequately disclose clinical trial risks, which may lead to further legal repercussions.
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Analyst Views on GOSS
Wall Street analysts forecast GOSS stock price to rise
4 Analyst Rating
3 Buy
1 Hold
0 Sell
Strong Buy
Current: 0.210
Low
10.00
Averages
12.33
High
15.00
Current: 0.210
Low
10.00
Averages
12.33
High
15.00
About GOSS
Gossamer Bio, Inc. is a late-stage, clinical biopharmaceutical company, which is focused on the development and commercialization of seralutinib for the treatment of pulmonary arterial hypertension and pulmonary hypertension associated with interstitial lung disease (PH-ILD). Seralutinib, also known as GB002, is an investigational inhaled, small-molecule, platelet-derived growth factor receptor (PDGFR), colony-stimulating factor 1 receptor (CSF1R), and c-KIT inhibitor, being evaluated in a Phase III clinical trial for the treatment of PAH. Seralutinib is designed to target the mechanisms that underlie pulmonary hypertension and to be delivered to the site of disease, via dry powder inhaler. Seralutinib is being evaluated in a Phase III clinical trial for the treatment of pulmonary arterial hypertension (PAH). Inhaled seralutinib, which is designed to act on both isoforms of the PDGFR, α and β, as well as the CSF1R and c-KIT pathways.
About the author
Emily J. Thompson
Emily J. Thompson, a Chartered Financial Analyst (CFA) with 12 years in investment research, graduated with honors from the Wharton School. Specializing in industrial and technology stocks, she provides in-depth analysis for Intellectia’s earnings and market brief reports.
Gossamer Bio Faces Class Action Lawsuit Over Phase 3 Study Results
- Class Action Initiated: Berger Montague PC has announced a class action lawsuit against Gossamer Bio on behalf of investors who purchased shares between June 16, 2025, and February 20, 2026, indicating significant investor dissatisfaction with the company's transparency.
- Clinical Trial Failure: Gossamer's PROSERA study results, announced on February 23, 2026, failed to meet the primary endpoint of improved six-minute walk distance (6MWD), leading to a substantial decline in investor confidence regarding the company's future prospects.
- Stock Price Plummet: Following the announcement, Gossamer's stock price dropped from $2.13 per share on February 20, 2026, to $0.42 per share on February 23, 2026, representing a loss of over 80% in a single day, reflecting market pessimism about its clinical outlook.
- Investor Rights Affected: Investors must apply by June 1, 2026, to be appointed as lead plaintiffs in the class action, demonstrating strong opposition to the company's failure to adequately disclose clinical trial risks, which may lead to further legal repercussions.
See More
Class Action Lawsuit Filed Against Gossamer Bio, Inc.
- Class Action Initiation: Bronstein, Gewirtz & Grossman, LLC has announced a class action lawsuit against Gossamer Bio, aiming to recover damages for investors who purchased securities between June 16, 2025, and February 20, 2026, highlighting significant issues in the company's trading practices during this period.
- False Statement Allegations: The complaint alleges that Gossamer Bio concealed critical adverse facts regarding the design flaws of its Phase 3 PROSERA study while promoting overwhelmingly positive results, particularly failing to adequately control for placebo responses at Latin American testing sites, leading investors to buy shares at inflated prices.
- Investor Losses: As a result of the concealment, Gossamer's securities traded at artificially inflated prices, causing significant losses for the plaintiff and other class members, which underscores a lack of corporate governance and transparency within the company.
- Legal Fee Arrangement: Bronstein, Gewirtz & Grossman, LLC will represent investors on a contingency fee basis, meaning they will only charge fees if they successfully recover losses, thereby reducing legal risks for investors and encouraging more affected parties to join the lawsuit.
See More
Gossamer Bio Faces Securities Class Action Lawsuit
- Lawsuit Background: Gossamer Bio, Inc. is facing a securities class action lawsuit following its February 23, 2026 announcement that the PROSERA study failed to meet its primary endpoint, covering the period from June 16, 2025, to February 20, 2026, which has led to significant investor losses.
- Stock Price Plunge: Following the lawsuit announcement, Gossamer's stock price plummeted by 80%, reflecting the market's strong disappointment with the clinical trial results, which directly impacts the company's market capitalization and investor confidence.
- Legal Investigation: Hagens Berman law firm has initiated an investigation into whether Gossamer violated federal securities laws, particularly regarding disclosures about the PROSERA trial design, which may have misled investors about the company's prospects.
- Investor Call to Action: The law firm encourages investors who suffered substantial losses during the class period to submit their loss information to support potential claims, highlighting a strong emphasis on corporate transparency and accountability.
See More
Gossamer Bio Faces Class Action Lawsuit Reminder
- Class Action Reminder: The Schall Law Firm reminds investors of a class action lawsuit against Gossamer Bio for violations of §§10(b) and 20(a) of the Securities Exchange Act of 1934 and SEC Rule 10b-5, concerning securities purchased between June 16, 2025, and February 20, 2026.
- False Statements Allegations: The complaint alleges that Gossamer concealed adverse facts regarding the design of its Phase 3 PROSERA study, particularly concerning controls for placebo response at certain testing sites, rendering its public statements false and materially misleading throughout the class period.
- Investor Losses: Following the revelation of the truth about Gossamer, investors suffered damages, and the Schall Law Firm encourages affected shareholders to contact them before June 1, 2026, to participate in the lawsuit and seek recovery of their losses.
- Legal Consultation Opportunity: The Schall Law Firm offers free legal consultations, allowing investors to reach out via phone or website to discuss their rights and decide whether to join the class action lawsuit.
See More
Reminder of Gossamer Bio Securities Class Action
- Class Action Notice: Rosen Law Firm reminds investors who purchased Gossamer Bio (NASDAQ: GOSS) securities between June 16, 2025, and February 20, 2026, that they must apply to be lead plaintiff by June 1, 2026, to participate in the class action and potentially receive compensation.
- Fee Arrangement: Investors joining the class action will incur no out-of-pocket expenses, as the law firm operates on a contingency fee basis, allowing investors to seek compensation without financial burden.
- Case Background: The lawsuit alleges that Gossamer Bio provided overly positive statements to investors while concealing material adverse facts regarding the design of its Phase 3 PROSERA study, particularly concerning the placebo response at Latin American testing sites, resulting in investor losses when the truth emerged.
- Law Firm's Strength: Rosen Law Firm specializes in securities class actions and has recovered over $438 million for investors in 2019 alone, having achieved the largest securities class action settlement against a Chinese company, demonstrating its expertise and successful track record in this field.
See More
Gossamer Bio Faces Class Action Lawsuit After Trial Failure
- Lawsuit Background: Gossamer Bio, Inc. is facing a class action lawsuit following its February 23, 2026 announcement that the PROSERA study failed to meet its primary endpoint, involving investors who purchased securities between June 16, 2025, and February 20, 2026, indicating potential missteps in clinical trial design.
- Stock Price Plunge: The stock price of Gossamer plummeted by 80% after the trial results were disclosed, which not only undermines investor confidence but may also adversely affect the company's future financing capabilities and market reputation.
- Legal Investigation: Hagens Berman has initiated an investigation into whether Gossamer violated federal securities laws, particularly regarding disclosures about the PROSERA trial design, potentially leading to significant losses for investors and highlighting deficiencies in the company's transparency.
- Investor Action: The law firm is urging investors who suffered losses to contact them before the June 1 deadline to represent their interests in legal proceedings, a move that may prompt greater scrutiny of the company's governance and transparency practices.
See More
Gossamer Bio Faces Class Action Lawsuit Over Phase 3 Study Results
- Class Action Initiated: Berger Montague PC has announced a class action lawsuit against Gossamer Bio on behalf of investors who purchased shares between June 16, 2025, and February 20, 2026, indicating significant investor dissatisfaction with the company's transparency.
- Clinical Trial Failure: Gossamer's PROSERA study results, announced on February 23, 2026, failed to meet the primary endpoint of improved six-minute walk distance (6MWD), leading to a substantial decline in investor confidence regarding the company's future prospects.
- Stock Price Plummet: Following the announcement, Gossamer's stock price dropped from $2.13 per share on February 20, 2026, to $0.42 per share on February 23, 2026, representing a loss of over 80% in a single day, reflecting market pessimism about its clinical outlook.
- Investor Rights Affected: Investors must apply by June 1, 2026, to be appointed as lead plaintiffs in the class action, demonstrating strong opposition to the company's failure to adequately disclose clinical trial risks, which may lead to further legal repercussions.
See More
Class Action Lawsuit Filed Against Gossamer Bio, Inc.
- Class Action Initiation: Bronstein, Gewirtz & Grossman, LLC has announced a class action lawsuit against Gossamer Bio, aiming to recover damages for investors who purchased securities between June 16, 2025, and February 20, 2026, highlighting significant issues in the company's trading practices during this period.
- False Statement Allegations: The complaint alleges that Gossamer Bio concealed critical adverse facts regarding the design flaws of its Phase 3 PROSERA study while promoting overwhelmingly positive results, particularly failing to adequately control for placebo responses at Latin American testing sites, leading investors to buy shares at inflated prices.
- Investor Losses: As a result of the concealment, Gossamer's securities traded at artificially inflated prices, causing significant losses for the plaintiff and other class members, which underscores a lack of corporate governance and transparency within the company.
- Legal Fee Arrangement: Bronstein, Gewirtz & Grossman, LLC will represent investors on a contingency fee basis, meaning they will only charge fees if they successfully recover losses, thereby reducing legal risks for investors and encouraging more affected parties to join the lawsuit.
See More
Gossamer Bio Faces Securities Class Action Lawsuit
- Lawsuit Background: Gossamer Bio, Inc. is facing a securities class action lawsuit following its February 23, 2026 announcement that the PROSERA study failed to meet its primary endpoint, covering the period from June 16, 2025, to February 20, 2026, which has led to significant investor losses.
- Stock Price Plunge: Following the lawsuit announcement, Gossamer's stock price plummeted by 80%, reflecting the market's strong disappointment with the clinical trial results, which directly impacts the company's market capitalization and investor confidence.
- Legal Investigation: Hagens Berman law firm has initiated an investigation into whether Gossamer violated federal securities laws, particularly regarding disclosures about the PROSERA trial design, which may have misled investors about the company's prospects.
- Investor Call to Action: The law firm encourages investors who suffered substantial losses during the class period to submit their loss information to support potential claims, highlighting a strong emphasis on corporate transparency and accountability.
See More
Gossamer Bio Faces Class Action Lawsuit Reminder
- Class Action Reminder: The Schall Law Firm reminds investors of a class action lawsuit against Gossamer Bio for violations of §§10(b) and 20(a) of the Securities Exchange Act of 1934 and SEC Rule 10b-5, concerning securities purchased between June 16, 2025, and February 20, 2026.
- False Statements Allegations: The complaint alleges that Gossamer concealed adverse facts regarding the design of its Phase 3 PROSERA study, particularly concerning controls for placebo response at certain testing sites, rendering its public statements false and materially misleading throughout the class period.
- Investor Losses: Following the revelation of the truth about Gossamer, investors suffered damages, and the Schall Law Firm encourages affected shareholders to contact them before June 1, 2026, to participate in the lawsuit and seek recovery of their losses.
- Legal Consultation Opportunity: The Schall Law Firm offers free legal consultations, allowing investors to reach out via phone or website to discuss their rights and decide whether to join the class action lawsuit.
See More
Reminder of Gossamer Bio Securities Class Action
- Class Action Notice: Rosen Law Firm reminds investors who purchased Gossamer Bio (NASDAQ: GOSS) securities between June 16, 2025, and February 20, 2026, that they must apply to be lead plaintiff by June 1, 2026, to participate in the class action and potentially receive compensation.
- Fee Arrangement: Investors joining the class action will incur no out-of-pocket expenses, as the law firm operates on a contingency fee basis, allowing investors to seek compensation without financial burden.
- Case Background: The lawsuit alleges that Gossamer Bio provided overly positive statements to investors while concealing material adverse facts regarding the design of its Phase 3 PROSERA study, particularly concerning the placebo response at Latin American testing sites, resulting in investor losses when the truth emerged.
- Law Firm's Strength: Rosen Law Firm specializes in securities class actions and has recovered over $438 million for investors in 2019 alone, having achieved the largest securities class action settlement against a Chinese company, demonstrating its expertise and successful track record in this field.
See More
Gossamer Bio Faces Class Action Lawsuit After Trial Failure
- Lawsuit Background: Gossamer Bio, Inc. is facing a class action lawsuit following its February 23, 2026 announcement that the PROSERA study failed to meet its primary endpoint, involving investors who purchased securities between June 16, 2025, and February 20, 2026, indicating potential missteps in clinical trial design.
- Stock Price Plunge: The stock price of Gossamer plummeted by 80% after the trial results were disclosed, which not only undermines investor confidence but may also adversely affect the company's future financing capabilities and market reputation.
- Legal Investigation: Hagens Berman has initiated an investigation into whether Gossamer violated federal securities laws, particularly regarding disclosures about the PROSERA trial design, potentially leading to significant losses for investors and highlighting deficiencies in the company's transparency.
- Investor Action: The law firm is urging investors who suffered losses to contact them before the June 1 deadline to represent their interests in legal proceedings, a move that may prompt greater scrutiny of the company's governance and transparency practices.
See More
