Vertex Presents Updated Phase 1/2 Data From RUBY-3 Study That Continue to Demonstrate Best-in-Class Potential for Povetacicept in Adults with IgA Nephropathy and Primary Membranous Nephropathy at American Society of Nephrology Kidney Week

Vertex Pharmaceuticals Incorporated (Nasdaq: VRTX) today announced updated data for povetacicept (pove) in IgA nephropathy (IgAN) and primary membranous nephropathy (pMN) from the ongoing RUBY-3 trial at the American Society of Nephrology (ASN) Kidney Week 2025 in Houston, Texas. Pove is an investigational recombinant fusion protein therapeutic and dual inhibitor of the BAFF (B cell activating factor) and APRIL (a proliferation inducing ligand) cytokines. Pove is the only BAFF+APRIL inhibitor in pivotal trials for multiple kidney diseases.

Results were presented today as a late-breaking oral presentation (SA-OR091) and included interim data from the open-label Phase 1/2 RUBY-3 trial, where adults with IgAN and pMN received pove subcutaneously every 4 weeks. The analysis included 21 participants with IgAN and 10 participants with pMN treated with pove at the 80mg dose, of which 17 participants and 5 participants, respectively, completed the Week 48 study visit.

Results in IgAN

In IgAN, key efficacy findings for the pove 80mg cohort at 48 weeks showed a 64% decrease from baseline in mean 24-hour urine protein to creatinine ratio (UPCR), estimated glomerular filtration rate (eGFR) stabilization with change from baseline in eGFR (mean±SE) of 3.3±3.1 mL/min/1.73m², 90% (9/10) of participants achieving hematuria resolution (defined as a decrease to negative or small levels of urine blood in participants with baseline levels of urine blood of moderate or large), and 53% of participants achieving clinical remission (defined as UPCR <0.5 g/g, negative hematuria, and <25% reduction in eGFR vs. baseline).

Results in pMN

In pMN, key efficacy findings for the pove 80mg cohort at 48 weeks showed an 82% decrease from baseline in mean 24-hour UPCR, eGFR stabilization with change from baseline in eGFR (mean±SE) of -0.3±3.4 mL/min/1.73m², and 40% of participants achieving complete clinical remission (defined as UPCR <0.5 g/g).

Pove was generally safe and well tolerated with adverse events (AEs) that were mostly mild or moderate in severity. There were no serious adverse events related to povetacicept. The safety data is consistent with previous interim analyses, and the safety profile is similar between the IgAN and pMN cohorts.

“These impressive data demonstrate the viability of BAFF+APRIL inhibition to transform the treatment of serious kidney diseases such as IgAN and pMN, important areas of high unmet need,” said RUBY-3 Principal Investigator James Tumlin, M.D., Professor, Department of Medicine, Emory University School of Medicine, and Director of Clinical Research at Georgia Nephrology. “In IgAN, it is especially encouraging to see that at 48 weeks of follow up, a full two-thirds of the participants treated with pove achieved a complete response as defined by UPCR <0.5 g/g, which is in line with the most recent KDIGO guidelines.”