Gossamer Bio (GOSS) Leerink’s Global Healthcare Conference 2025 summary

Key clinical development updates

• Phase III PROSERA study for pulmonary hypertension expects enrollment completion in Q2 and top-line data in Q4, targeting a 2027 launch.

• Phase III study in PH-ILD to begin in the second half of the year, with first patient likely enrolled early Q4.

• Enrollment strategy focused on global sites, with 70% outside the US, leveraging strong infrastructure in Europe and Latin America.

• Enrichment criteria ensure inclusion of intermediate-risk patients, using REVEAL Lite 2 and additional hemodynamic markers.

• Patient population in PROSERA is as sick or sicker than comparator studies, maximizing potential for clinical benefit.

Competitive landscape and differentiation

• Recent competitor setbacks (Keros, Aerovate) leave seralutinib as the only phase III candidate in pulmonary hypertension.

• Merck's sotatercept (Winrevair) is the main competitor but faces safety and dosing challenges, creating opportunity for seralutinib.

• Seralutinib aims for best-in-class safety and efficacy, with no hemoglobin-related side effects seen in competitors.

• Imaging and biomarker data support seralutinib's role as a remodeling agent, with evidence of revascularization and right ventricular protection.

• Inhaled delivery and improved formulation (reduced puff burden) enhance commercial and patient appeal.

Efficacy, safety, and long-term outlook

• Clinically meaningful improvement in Six-minute walk distance targeted, with 25 meters considered highly relevant without hemoglobin increase.

• Long-term data show durable and progressive benefits, with no new safety signals up to 144 weeks.

• Early treatment with seralutinib may allow patients to stay on therapy for years, potentially delaying or reducing need for other interventions.

• Imaging and biomarker sub-studies in PROSERA aim to validate disease-modifying effects.

• Commercial strategy validated by partnership with Chiesi, supporting pricing and market access in the EU.