Gossamer Bio, Inc. Q1 FY2025 earnings call

Key Points

• Faheem Hasnain announced the closure of new patient screenings in the Phase III PROSERA study for pulmonary arterial hypertension (PAH). The baseline characteristics of enrolled patients, such as an average 6-minute walk distance of ~376 meters (lower than TORREY study), mean NT-proBNP of 96 ng/L (more severe than TORREY), and 74% functional Class III patients, position the study for success.
• Collaboration with Chiesi Group for the Phase III SERANATA study in pulmonary hypertension-associated interstitial lung disease (PH-ILD) was highlighted. The SERANATA study will be a global, double-blind, placebo-controlled trial with ~480 patients, targeting change in 6-minute walk distance at week 24 as the primary endpoint and forced vital capacity as a key secondary endpoint.

Recognized revenue for the quarter ended March 31, 2025, was $9.9 million. R&D expenses were $38 million, compared to $32.4 million in the same period of 2024. G&A expenses were $8.7 million, down from $9.6 million in 2024. Net loss for the quarter was $36.6 million, or $0.16 per share. The company ended the quarter with $257.9 million in cash and cash equivalents and marketable securities.

Forward-Looking Statements

• Anticipate completing the blinded portion of the PROSERA study, including the 24-week primary endpoint, by the fourth quarter of 2025, with top-line results announced in February 2026.
• The Phase III SERANATA study for PH-ILD is expected to begin first site activations in the fourth quarter of 2025.

Q: With 343 patients enrolled in PROSERA to date, have you considered stopping enrollment there in order to be able to still report data this year?

A: Faheem stated they honored the commitment to enroll all qualifying patients, with enrollment to finish by mid-June, and top-line results in February 2026 due to the need for thorough data scrubbing and analysis.

Q: Did you look at baseline PVR in the PROSERA study?

A: Faheem mentioned PVR entry criteria was 400 or greater, but PVR was not a mandated endpoint. Further baseline updates were not expected to materially change given the number of patients evaluated.

Q: Given endpoints of both PH-ILD and PAH studies are 6-minute walk test, any read-through from PROSERA to SERANATA?

A: Faheem and Richard noted that a positive PROSERA could portend a positive SERANATA, with PH-ILD patients being sicker overall but expecting a similar treatment effect logic to apply.