Povetacicept

A dual BAFF/APRIL blocker for IgA nephropathy that is under FDA review, with a decision date of November 30, 2026. Povetacicept blocks 2 immune signals at once, and in its Phase 3 RAINIER trial it cut urine protein by 49.8% more than placebo at week 36. It received FDA Breakthrough Therapy Designation.

Povetacicept blocks two proteins at once: BAFF and APRIL. Both of these proteins activate immune B cells that produce the defective IgA antibodies damaging your kidneys. By blocking both signals, povetacicept is designed to cut production of those harmful antibodies. No trial has compared it with drugs that block APRIL alone.

In the RAINIER interim safety data from 557 patients treated for about 34 weeks on average, the most common side effects were upper respiratory infections (18.3% on povetacicept vs 11.4% on placebo) and injection site reactions (14.5% vs 2.2%), and every injection site reaction was mild or moderate. Serious side effects occurred in 3.0% of patients on povetacicept vs 4.3% on placebo, none were judged related to the drug, and there were no opportunistic infections^[2]. Because povetacicept lowers antibody production, infection risk is the main safety question, and fuller safety data will come from the 2-year trial.

Given as a subcutaneous (under the skin) injection of 80 mg every 4 weeks in the RAINIER trial. If approved, Vertex plans to launch it in a small autoinjector holding under 0.5 mL for use at home once every 4 weeks^[2].

Not yet. Povetacicept is under FDA review for IgA Nephropathy; Vertex Pharmaceuticals has filed an application and a decision is due November 30, 2026. The FDA calendar page tracks the outcome.

Both block BAFF and APRIL, but povetacicept uses an engineered TACI domain. Vertex says it showed improved binding and potency compared with other BAFF and APRIL blockers in preclinical studies, though it has not been compared with atacicept in patients. Povetacicept received FDA Breakthrough Therapy Designation in September 2025 and is under FDA review with a decision date of November 30, 2026, while atacicept was FDA-approved as Trutakna in July 2026.

RAINIER is the Phase 3 trial of povetacicept in adults with biopsy-confirmed IgA nephropathy. Its Week 36 interim analysis of 199 patients showed a 49.8% placebo-adjusted drop in urine protein, which supports Vertex's application for accelerated approval. The trial continues in order to show whether povetacicept protects kidney function over the long term.

In the RAINIER trial, povetacicept is given as an 80 mg injection under the skin every 4 weeks. If it is approved, Vertex plans to launch it in a small autoinjector holding under 0.5 mL for use at home.

Povetacicept was developed by Alpine Immune Sciences under the code ALPN-303. Vertex Pharmaceuticals acquired Alpine in 2024 and has filed for FDA accelerated approval. The FDA decision date is November 30, 2026.

FDA Breakthrough Therapy Designation is granted to drugs intended to treat serious conditions where preliminary clinical evidence shows substantial improvement over existing therapies. Povetacicept received this designation in September 2025 for IgA nephropathy.