Atrasentan Hydrochloride

With its latest readout, Vertex appears well on its way to establishing itself in another disease area beyond cystic fibrosis. The Boston biotech described a Phase 3 win on Monday for its drug povetacicept in treating a severe kidney disease, paving the way to complete an accelerated approval filing by month’s end. The readout was Vertex’s most anticipated data reveal for this year’s first half and also a test of the wisdom behind getting its hands on the drug through its $4.9 billion buyout of Alpine Immune Sciences in 2024. The interim data come from the ongoing RAINIER trial, studying the disease called immunoglobulin A nephropathy, or IgAN. The disease deteriorates kidney function over time, with most adult patients progressing to end-stage kidney disease or dying within 20 years of diagnosis, according to Vertex. Povetacicept blocks two cytokines, BAFF and APRIL, that are implicated in a variety of autoimmune conditions, including IgAN. Vertex said the drug reduced the urine protein-to-creatinine ratio — an early indicator of IgAN — by 52% from baseline after 36 weeks. That is relatively on par with rival drugs like Otsuka’s Voyxact and Vera Therapeutics’ atacicept. The FDA has already granted several accelerated approvals for other drugs to treat IgAN based on their ability to reduce urinary protein levels. Wall Street analysts were generally enthused by the data, having already forecast $4.47 billion in peak annual sales for Vertex’s drug, according to consensus estimates from Visible Alpha. The market was too, sending Vertex’s shares $VRTX up about 9.5% on Tuesday morning. At a Jefferies investor conference on Tuesday, Vertex chief commercial officer Duncan McKechnie described the drug’s dosing regimen — as a monthly, at-home auto-injector — as a potential key advantage in winning over physicians. Povetacicept plays a key part in Vertex’s strategy to diversify beyond its suite of cystic fibrosis drugs. On Monday, CEO Reshma Kewalramani described kidney-related diseases as “Vertex’s fourth franchise alongside cystic fibrosis, hematology and acute pain.” Some of those other franchises have gotten off to relatively slow starts. Casgevy, its CRISPR-based sickle cell therapy, brought in $115.8 million in 2025 sales, and Journavx, its non-opioid pain pill approved in January 2025, made $59.6 million last year. While those launches are still in early stages, investors are watching closely to see if they can scale into meaningful, revenue-driving products for a $125 billion company. Povetacicept is, in many ways, a much larger gamble by Vertex. It was the star drug behind Vertex’s Alpine acquisition. Jeffrey Leiden, the company’s executive chair and former CEO, led the deal talks and compared the drug’s potential to Humira, one of the all-time best-selling medicines. Vertex has a long way to go in turning Leiden’s hopes into reality. Humira became a massive blockbuster by stringing together many approvals, establishing the “pipeline-in-a-product” strategy that has proven easier for drug companies to try than to actually pull off. Looking beyond IgAN with povetacicept, Vertex plans to start the Phase 3 portion of an ongoing study in another common kidney disease, primary membranous nephropathy, in mid-2026. It also expects to start a Phase 2 proof-of-concept trial in generalized myasthenia gravis, a rare autoimmune disease, in the first half of this year. While the IgAN data look sufficient for approval, analysts expect the company will likely be entering a competitive and growing market of treatment options for IgAN. Stifel analyst Paul Matteis wrote in a Monday note to investors that it’s “not entirely clear at this time whether it’s differentiated from other key competitors.” Beyond recent approvals like Novartis’ Vanrafia and Otsuka’s Voyxact, Novartis also expects a Phase 3 readout of an anti-APRIL antibody called zigakibart in the first half of 2027. Upstart biotechs like Jade Biosciences and Climb Bio are advancing earlier-stage programs against similar targets. Matteis suggested povetacicept may wind up winning market share based on convenience and safety, more than its efficacy. Kyle LaHucik contributed reporting to this story.