Clinical Efficacy: 6-Minute Walk Distance Improvement
PROSERA Phase III showed a placebo-adjusted improvement of 13.3 meters in 6-minute walk distance (6MWD) at week 24: seralutinib improved 28.2 m from baseline vs 13.5 m for placebo (p = 0.032). The result met the traditional 0.05 significance threshold.
Secondary Endpoints and Risk-Enriched Subgroup
All four key secondary endpoints favored seralutinib over placebo, with a stronger effect observed in the prespecified risk-enriched subgroup, supporting consistency across clinical measures.
Robust Mechanistic Imaging Evidence (CT FRI Substudy)
162 patients enrolled in the prespecified CT FRI substudy with 125 evaluable paired baseline and week-24 scans. Results showed multi-compartment structural reverse remodeling (arterial, venous, fibrosis-like parenchymal and vascular complexity parameters) that correlated with clinical endpoints (6MWD, NT-proBNP, REVEAL Lite 2). Notable findings included statistically significant reductions in large arterial blood volume proportion (BV10A) and reductions in fibrosis-like parenchymal volume, and increases in total venous blood volume and venous branching.
Regulatory Progress: Type B Pre-NDA Meeting and NDA Timeline
FDA granted an in-person Type B pre-NDA meeting (briefing book submitted) scheduled for mid-June. Company is targeting an NDA submission in September 2026 and, if process proceeds as expected, a potential approval in Q3 2027.
Capital Structure Action: Convertible Note Exchange
Agreement terms would reduce outstanding convertible debt from $200 million to $72 million (a $128 million reduction, ~64% decrease) on a fully subscribed basis, extend maturity from 2027 to 2030, and issue new secured convertible notes bearing 7.5% cash interest (paid semiannually). Early tender incentives include equity consideration and warrants.
Cost Containment and Focus on NDA Execution
Company implemented rapid cost stewardship actions (including a targeted reduction in force and pausing non-essential development) to preserve runway and focus resources on NDA submission and potential commercialization.