Vertex Achieves 52% Proteinuria Drop in Phase III, Files FDA Submission
Vertex reported phase III RAINER interim data showing 52% proteinuria reduction at 36 weeks, outperforming placebo by 49.8% with all secondary endpoints met and favorable safety. Company expects to complete FDA rolling submission for accelerated approval of povetacicept by month-end, leveraging a PRV to cut review time by four months.
1. Interim Phase III Results
Interim analysis of the phase III RAINER study showed that 36-week treatment with povetacicept reduced proteinuria by 52% versus baseline and outperformed placebo by 49.8%, meeting the primary endpoint alongside all secondary measures.
2. FDA Submission Timeline
Vertex initiated a rolling FDA submission for accelerated approval in fourth-quarter 2025 and anticipates completing the filing by the end of March 2026, using a priority review voucher to reduce the review timeline by four months.
3. Safety and Secondary Endpoints
Treatment was generally safe and well-tolerated, with no new safety signals reported across study participants and full achievement of all secondary endpoints assessing renal function biomarkers.
4. Market Outlook and Competition
If approved, povetacicept could enter a market with existing therapies like Tarpeyo, Fabhalta and Filspari, while Vertex also advances pivotal trials in primary membranous nephropathy and plans a mid-stage study in generalized myasthenia gravis.