Gossamer Bio's Phase 3 Trial Results Disappoint
Written by Emily J. Thompson, Senior Investment Analyst
Updated: Feb 23 2026
0mins
Should l Buy GOSS?
Source: Benzinga
Gossamer Bio's shares fell sharply, hitting a 52-week low, following disappointing results from its Phase 3 PROSERA trial for seralutinib, which showed significant but insufficient improvement in patient mobility.
The trial revealed that seralutinib led to a median change of +28.2 meters in Six-Minute Walk Distance (6MWD) at Week 24, failing to meet the predefined efficacy threshold. However, in a subgroup of patients with connective tissue disease-associated pulmonary arterial hypertension, the drug achieved a placebo-adjusted gain of +37.0 meters, indicating potential effectiveness. Gossamer plans to meet with the U.S. FDA to discuss future development for seralutinib while pausing enrollment in the SERANATA study to evaluate the impact of these results.
The market reacted negatively, with Gossamer Bio's shares plummeting by 77.12% to $0.59, reflecting investor disappointment and prompting analysts to lower their earnings expectations.
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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: 0.425
Low
10.00
Averages
12.33
High
15.00
Current: 0.425
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 Under Investigation After 80.1% Stock Plunge Following Trial Failure
- Legal Investigation Initiated: The Schall Law Firm has announced an investigation into Gossamer Bio, focusing on potential violations of securities laws, particularly regarding the issuance of false or misleading statements that could affect investor decisions.
- Clinical Trial Failure: On February 23, 2026, Gossamer disclosed that its product candidate seralutinib failed to meet its primary endpoint in the Phase 3 PROSERA trial, leading to a significant loss of market confidence.
- Stock Price Plunge: Following this announcement, Gossamer's shares plummeted by over 80.1% on the same day, severely impacting shareholder investment value and potentially triggering further legal actions.
- Investor Rights Protection: The Schall Law Firm encourages affected shareholders to reach out for discussions on protecting their rights, demonstrating the firm's commitment to supporting investor interests.
See More
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- Weight Loss Innovation: Allurion Technologies' gastric balloon system gained FDA approval, offering a non-surgical weight loss option for patients with a BMI of 30-40, which is anticipated to expand the company's market share in the obesity sector.
- Acquisition Deal: Gilead Sciences is acquiring Arcellx for $115 per share, totaling $7.8 billion, a move that will strengthen Gilead's position in cell therapy and enhance its collaboration with Kite Pharma.
- Clinical Trial Developments: Novo Nordisk's CagriSema missed key goals in its trial against Zepbound, although it demonstrated a favorable safety profile, which may influence future market strategies.
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Gossamer Bio Under Investigation After 80% Stock Plunge
- Securities Fraud Investigation: Pomerantz LLP is investigating whether Gossamer Bio and its executives have engaged in securities fraud or other unlawful business practices, raising serious concerns about corporate governance and compliance.
- Clinical Trial Failure: On February 23, 2026, Gossamer announced that its Phase 3 PROSERA trial for pulmonary arterial hypertension failed to meet its primary endpoint, directly impacting investor confidence.
- Stock Price Plunge: Following the trial results, Gossamer's stock price fell by $1.71, a staggering 80.14% drop, closing at $0.423 per share, reflecting market pessimism regarding the company's future prospects.
- Investor Alert: Pomerantz LLP advises investors to contact their attorneys for more information, indicating that the firm is actively seeking to provide legal support for affected investors, potentially leading to more class action lawsuits.
See More
Gossamer Bio Reports Phase 3 Results for Seralutinib in Pulmonary Arterial Hypertension
- Clinical Trial Results: Gossamer Bio's Phase 3 PROSERA study for pulmonary arterial hypertension indicates that while seralutinib narrowly missed a key statistical threshold, it remains a viable treatment option, particularly showing greater activity in patients with advanced disease, which could provide hope for future treatment protocols.
- Stock Price Plunge: Following the disappointing trial results, Gossamer Bio's shares plummeted 80.1% to close at $0.4233, reflecting a pessimistic market sentiment regarding the company's future prospects, which may impact its ability to raise funds and investor confidence.
- Analyst Downgrades: Multiple analysts downgraded Gossamer Bio, with Leerink Partners lowering its rating from Outperform to Market Perform and slashing the price target from $6 to $1, indicating significant concerns about the company's future performance and market position.
- FDA Discussion Plans: The company intends to discuss the findings with the FDA, aiming to leverage the data demonstrating greater activity in advanced patients to seek further support, which could pave the way for future drug approvals despite the current challenges.
See More
Wall Street Analysts Adjust Ratings
- Analyst Rating Changes: Top Wall Street analysts have adjusted their ratings on several companies, including upgrades, downgrades, and initiations, reflecting varying market perceptions and expectations regarding these firms.
- Market Impact: These rating changes could influence investor decisions, particularly among those considering purchasing NVO stock, as analysts' opinions will serve as a crucial reference point.
- Source of Updates: A complete view of all analyst rating changes can be found on Benzinga's analyst ratings page, providing comprehensive market insights and analysis.
- Investment Advice Disclaimer: Benzinga reminds investors that it does not provide investment advice, and all information is for reference only, urging investors to assess risks independently.
See More
U.S. Stocks Decline as Dow Jones Drops Over 700 Points
- Dow Jones Decline: On Monday, the Dow Jones index fell over 700 points, a decline of 1.46% to 48,901.83, reflecting market concerns about economic outlook and potentially diminishing investor confidence.
- Earnings Beat Expectations: The company reported operating earnings of 68 cents per share, exceeding the consensus estimate of 67 cents and up from 58 cents a year earlier, indicating improved profitability.
- Significant Revenue Growth: Total operating revenue rose to $4.093 billion, surpassing analyst expectations of $3.653 billion and increasing by 20.38% year-over-year, demonstrating enhanced competitive strength in the market.
- Commodity Market Fluctuations: On Monday, oil prices fell by 0.3% to $66.26, while gold rose by 2.9% to $5,225.90, indicating investors are seeking safe-haven assets amid uncertain market conditions.
See More
Gossamer Bio Under Investigation After 80.1% Stock Plunge Following Trial Failure
- Legal Investigation Initiated: The Schall Law Firm has announced an investigation into Gossamer Bio, focusing on potential violations of securities laws, particularly regarding the issuance of false or misleading statements that could affect investor decisions.
- Clinical Trial Failure: On February 23, 2026, Gossamer disclosed that its product candidate seralutinib failed to meet its primary endpoint in the Phase 3 PROSERA trial, leading to a significant loss of market confidence.
- Stock Price Plunge: Following this announcement, Gossamer's shares plummeted by over 80.1% on the same day, severely impacting shareholder investment value and potentially triggering further legal actions.
- Investor Rights Protection: The Schall Law Firm encourages affected shareholders to reach out for discussions on protecting their rights, demonstrating the firm's commitment to supporting investor interests.
See More
Significant Milestones in Biotech Sector This Week
- FDA Drug Approvals: Armata Pharmaceuticals' AP-SA02 received FDA's QIDP designation, granting five years of market exclusivity and paving the way for a Phase 3 trial in 2026, which is expected to significantly enhance the company's competitive edge in the antibiotic market.
- Weight Loss Innovation: Allurion Technologies' gastric balloon system gained FDA approval, offering a non-surgical weight loss option for patients with a BMI of 30-40, which is anticipated to expand the company's market share in the obesity sector.
- Acquisition Deal: Gilead Sciences is acquiring Arcellx for $115 per share, totaling $7.8 billion, a move that will strengthen Gilead's position in cell therapy and enhance its collaboration with Kite Pharma.
- Clinical Trial Developments: Novo Nordisk's CagriSema missed key goals in its trial against Zepbound, although it demonstrated a favorable safety profile, which may influence future market strategies.
See More
Gossamer Bio Under Investigation After 80% Stock Plunge
- Securities Fraud Investigation: Pomerantz LLP is investigating whether Gossamer Bio and its executives have engaged in securities fraud or other unlawful business practices, raising serious concerns about corporate governance and compliance.
- Clinical Trial Failure: On February 23, 2026, Gossamer announced that its Phase 3 PROSERA trial for pulmonary arterial hypertension failed to meet its primary endpoint, directly impacting investor confidence.
- Stock Price Plunge: Following the trial results, Gossamer's stock price fell by $1.71, a staggering 80.14% drop, closing at $0.423 per share, reflecting market pessimism regarding the company's future prospects.
- Investor Alert: Pomerantz LLP advises investors to contact their attorneys for more information, indicating that the firm is actively seeking to provide legal support for affected investors, potentially leading to more class action lawsuits.
See More
Gossamer Bio Reports Phase 3 Results for Seralutinib in Pulmonary Arterial Hypertension
- Clinical Trial Results: Gossamer Bio's Phase 3 PROSERA study for pulmonary arterial hypertension indicates that while seralutinib narrowly missed a key statistical threshold, it remains a viable treatment option, particularly showing greater activity in patients with advanced disease, which could provide hope for future treatment protocols.
- Stock Price Plunge: Following the disappointing trial results, Gossamer Bio's shares plummeted 80.1% to close at $0.4233, reflecting a pessimistic market sentiment regarding the company's future prospects, which may impact its ability to raise funds and investor confidence.
- Analyst Downgrades: Multiple analysts downgraded Gossamer Bio, with Leerink Partners lowering its rating from Outperform to Market Perform and slashing the price target from $6 to $1, indicating significant concerns about the company's future performance and market position.
- FDA Discussion Plans: The company intends to discuss the findings with the FDA, aiming to leverage the data demonstrating greater activity in advanced patients to seek further support, which could pave the way for future drug approvals despite the current challenges.
See More
Wall Street Analysts Adjust Ratings
- Analyst Rating Changes: Top Wall Street analysts have adjusted their ratings on several companies, including upgrades, downgrades, and initiations, reflecting varying market perceptions and expectations regarding these firms.
- Market Impact: These rating changes could influence investor decisions, particularly among those considering purchasing NVO stock, as analysts' opinions will serve as a crucial reference point.
- Source of Updates: A complete view of all analyst rating changes can be found on Benzinga's analyst ratings page, providing comprehensive market insights and analysis.
- Investment Advice Disclaimer: Benzinga reminds investors that it does not provide investment advice, and all information is for reference only, urging investors to assess risks independently.
See More
U.S. Stocks Decline as Dow Jones Drops Over 700 Points
- Dow Jones Decline: On Monday, the Dow Jones index fell over 700 points, a decline of 1.46% to 48,901.83, reflecting market concerns about economic outlook and potentially diminishing investor confidence.
- Earnings Beat Expectations: The company reported operating earnings of 68 cents per share, exceeding the consensus estimate of 67 cents and up from 58 cents a year earlier, indicating improved profitability.
- Significant Revenue Growth: Total operating revenue rose to $4.093 billion, surpassing analyst expectations of $3.653 billion and increasing by 20.38% year-over-year, demonstrating enhanced competitive strength in the market.
- Commodity Market Fluctuations: On Monday, oil prices fell by 0.3% to $66.26, while gold rose by 2.9% to $5,225.90, indicating investors are seeking safe-haven assets amid uncertain market conditions.
See More
