Gossamer Bio's Phase 3 Trial Results Disappoint
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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- 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.

- 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.
- 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.
- 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.
- Stock Plunge: Gossamer Bio, Inc. shares plummeted over 75% on February 23, 2026, after the company announced that its Phase 3 PROSERA trial for pulmonary arterial hypertension failed to meet its primary endpoint, significantly undermining investor confidence.
- Legal Investigation: Block & Leviton is investigating potential securities law violations by Gossamer Bio, aiming to recover losses for affected investors, highlighting serious concerns regarding the company's governance and accountability.
- Investor Eligibility: All investors who purchased Gossamer Bio common stock and experienced losses are encouraged to contact Block & Leviton to explore legal avenues for recovery, reflecting growing investor anxiety about the company's future prospects.
- Whistleblower Rewards: Block & Leviton informs potential whistleblowers that providing non-public information to the SEC could yield rewards of up to 30%, aiming to incentivize participation in the investigation and enhance investor protection efforts.







