Vertex Pharmaceuticals will head to US regulators after its immunoglobulin A nephropathy (IgAN) drug povetacicept was successful in a Phase III trial.
The ongoing Phase III RAINER trial (NCT06564142) met its primary endpoint, with patients treated with 80mg povetacicept once every four weeks achieving a 52% reduction in urine protein to creatinine ratio (UPCR) after 36 weeks. The placebo-adjusted UPCR reduction of 49.8% was clinically and statistically meaningful at the same timepoint. The reduction in proteinuria was consistent across all pre-specified subgroups.
Go deeper with GlobalData
Discover B2B Marketing That Performs
Combine business intelligence and editorial excellence to reach engaged professionals across 36 leading media platforms.
One of the trial’s secondary endpoints of serum galactose-deficient IgA1 reduction was also met, with povetacicept-treated patients achieving a 77.4% reduction compared to a 9.1% increase in the placebo group, yielding a reduction of 79.3% compared to placebo.
The other secondary endpoint of haematuria resolution was achieved in 85.1% of patients who received the study drug compared with 23.4% in the placebo cohort.
Povetacicept was generally safe and well-tolerated. The majority of adverse events (AEs) were mild to moderate. There were no serious adverse events (SAEs) related to povetacicept and no deaths in the trial.
Dr Reshma Kewalramani, CEO of Vertex, said: “As a nephrologist, I am struck by the rapid, deep and sustained response to povetacicept, as well as the consistency of benefit across all subgroups. These results are important for patients with IgAN and also bring us one step closer to realising povetacicept’s pipeline-in-a-product promise.”
US Tariffs are shifting - will you react or anticipate?
Don’t let policy changes catch you off guard. Stay proactive with real-time data and expert analysis.
By GlobalDataVertex Pharmaceuticals’ stock, listed on the Nasdaq exchange, rose 5.9% between market open on 9 March, before the announcement, and market open on 10 March. The company’s stock is continuing to rise on 10 March.
Positive data from acquired candidate
Vertex acquired povetacicept through a $4.9bn takeover of Alpine Immune Sciences in April 2024. As well as IgAN, it is being investigated in the ongoing Phase II/III OLYMPUS trial (NCT07204275) for primary membranous nephropathy (PMN),
Povetacicept is an engineered fusion protein and dual inhibitor of the BAFF (B cell activating factor) and APRIL (a proliferation-inducing ligand) cytokines.
The US Food and Drug Administration (FDA) granted a rolling review of the Biologics License Application (BLA) for Vertex’s drug in IgAN, a serious autoimmune disease that can lead to kidney failure or death in a large proportion of patients within 20 years of diagnosis.
Some data has already been submitted, but Vertex will now complete the full BLA submission by the end of March 2025 as it hopes to gain accelerated approval. The company is using a priority review voucher (PRV) to expedite the review of the povetacicept.
If povetacicept is approved by the FDA, Vertex plans to launch the drug as a low-volume (<0.5 mL) subcutaneous auto-injector delivered once every four weeks via at-home administration.
The RAINIER trial is ongoing and final analysis will occur at two years of treatment, with a primary endpoint of total estimated glomerular filtration rate (eGFR) slope through week 104.
IgAN market already home to key players
On the market, povetacicept will compete against several drugs, including Otsuka’s Voyxact (sibeprenlimab-szsi), which gained FDA approval in November 2025. Novartis also received accelerated approval for Vanrafia (atrasentan) in April 2025, showing there is increased competition on the market.
More established therapies include Calliditas Therapeutics’ Tarpeyo (budesonide), which gained accelerated approval by the FDA in 2021, and Travere Therapeutics’ Filspari (sparsentan), which gained accelerated approval in 2023.
