Gossamer Bio reports clinical, financial, and corporate updates tied to seralutinib, its investigational inhaled tyrosine kinase inhibitor for pulmonary arterial hypertension and pulmonary hypertension associated with interstitial lung disease. Recurring developments include Phase 3 study results, regulatory pathway updates, collaboration activity with Chiesi Group, quarterly financial results, and capital allocation updates.
Company news also covers Nasdaq Rule 5635(c)(4) employment inducement grants under the 2023 Employment Inducement Incentive Award Plan, investor conference participation, and business development or resource-allocation actions related to its pulmonary hypertension strategy.
Gossamer Bio (Nasdaq: GOSS) reported Q4 and full-year 2025 results, provided a corporate update, and outlined next steps after PROSERA Phase 3 topline data.
Key points: PROSERA narrowly missed its prespecified alpha at Week 24; prespecified higher‑risk and CTD‑PAH subgroups showed larger 6MWD gains. Enrollment in the PH‑ILD SERANATA study is paused. Year‑end cash and marketable securities were $136.9 million, funding operations into Q1 2027.
Gossamer Bio (Nasdaq: GOSS) reported topline Phase 3 PROSERA results for seralutinib in pulmonary arterial hypertension (PAH). The primary endpoint showed a placebo‑adjusted 6MWD improvement of +13.3 m at Week 24 (p=0.0320), missing the prespecified alpha of 0.025. Key secondary endpoints favored seralutinib, including a -120.4 ng/L NT‑proBNP reduction (p=0.0002). Prespecified intermediate/high‑risk patients (n=234) achieved a +20.0 m placebo‑adjusted 6MWD (p=0.0207). Safety was generally consistent with prior studies, though transaminase elevations ≥3x ULN occurred in 13% of seralutinib patients versus 1% placebo. Gossamer plans to meet the FDA and paused SERANATA enrollment to evaluate regional results.
Gossamer Bio (Nasdaq: GOSS) announced that its Compensation Committee approved an inducement grant of non‑qualified stock options to three non‑executive employees, effective January 5, 2026.
The awards cover an aggregate of 212,500 options with an exercise price of $2.74 per share (equal to the Jan 5, 2026 closing price), a 10‑year term, and vest over four years (25% at one year, then 36 monthly installments), subject to the 2023 Inducement Plan and individual option agreements.
Gossamer Bio (Nasdaq: GOSS) announced an inducement stock option grant approved by its Compensation Committee, effective December 5, 2025, to a newly hired non-executive employee under the 2023 Inducement Plan.
The award allows purchase of up to 200,000 common shares at an exercise price of $3.33 per share (the closing Nasdaq price on December 5, 2025). Options carry a 10-year term and vest over four years (25% after one year, then monthly over 36 months), subject to continued employment and plan terms.
Gossamer Bio (NASDAQ: GOSS) will participate in two investor conferences in December to discuss clinical progress and corporate strategy for seralutinib.
Piper Sandler 37th Annual Healthcare Conference: presentation and 1x1 meetings on December 2, 2025 at 9:00 AM ET in New York, NY. Oppenheimer Movers in Rare Disease Summit: panel and 1x1 meetings on December 11, 2025 at 9:00 AM ET in New York, NY.
Both events provide opportunities for investor Q&A on seralutinib development for PAH and PH-ILD.
Gossamer Bio (Nasdaq: GOSS) announced an inducement grant approved by its Compensation Committee effective November 5, 2025 under the 2023 Inducement Plan.
Six non-executive employees received non-qualified stock options to purchase an aggregate of 378,996 shares at an exercise price of $2.37 per share (the Nasdaq closing price on November 5, 2025). Options have a 10-year term and vest over four years: 25% on the one‑year anniversary and the remainder in 36 monthly installments, subject to continued employment and plan terms.
Gossamer Bio (Nasdaq: GOSS) will participate in two investor conferences in November 2025 to discuss its late‑stage clinical program for seralutinib in pulmonary arterial hypertension (PAH) and pulmonary hypertension associated with interstitial lung disease (PH‑ILD).
Planned events: a series of 1x1 meetings at the UBS Global Healthcare Conference on November 10, 2025 in Palm Beach, FL, and a presentation and 1x1s at the Guggenheim Securities Healthcare Innovation Conference on November 11, 2025 at 10:00 AM ET in Boston, MA (webcast available).
Gossamer Bio (NASDAQ: GOSS) reported third-quarter 2025 results and a program update on November 5, 2025. Key corporate facts: cash, cash equivalents and marketable securities of $180.2 million as of September 30, 2025, with management saying this provides runway into 2027. The Phase 3 PROSERA study completed enrollment at 390 PAH patients and topline results are expected in February 2026. The first site was activated for the registrational Phase 3 SERANATA study in PH‑ILD (~480 patients randomized across two doses and placebo). Q3 2025 revenue from Chiesi was $13.3M; net loss was $48.2M (Q3 2024: $30.8M).
Gossamer Bio (NASDAQ:GOSS) has entered into an option agreement to acquire Respira Therapeutics, a Samsara BioCapital portfolio company. The deal centers around RT234, a first-in-class inhaled vardenafil powder being developed as an as-needed (PRN) treatment for pulmonary hypertension (PH).
As part of the agreement, Gossamer will issue 2.5 million shares upfront and an additional 1.5 million shares upon exercising the acquisition option. The deal includes success-based milestone payments and royalties on potential RT234 sales. During the two-year option period, Gossamer will fund CMC development activities for RT234.
Gossamer Bio (NASDAQ:GOSS) has entered into an option agreement to acquire Respira Therapeutics and its lead candidate RT234, an inhaled, on-demand vardenafil treatment for pulmonary hypertension. The deal structure involves no upfront cash, with Gossamer issuing 2.5 million shares (1% of outstanding shares) at signing and 1.5 million additional shares upon option exercise.
RT234 is designed to provide rapid symptom relief for PAH and PH-ILD patients, addressing an unmet need where no on-demand treatments currently exist. The drug has shown promising results in two Phase 2 studies, demonstrating improvements in hemodynamics and functional measures. The company plans to pursue a 505(b)(2) regulatory pathway in the US, with potential clinical trials starting no earlier than 2027.