William Blair analyst Myles Minter in a Monday note to investors said that Vertex’s povetacicept “has maintained its potential to be a best-in-class asset” in the IgA nephropathy space and could become a “multibillion-dollar pipeline-in-a-drug product” for autoimmune disorders, while “outstanding questions” remain for Biogen’s felzartamab before moving into pivotal studies.
At the American Society of Nephrology’s Kidney Week Congress last week, Biogen and Vertex Pharmaceuticals unveiled mid-stage data for their respective IgA nephropathy programs, touting strong clinical efficacy and promising benefits.
On Saturday, Biogen presented complete data from the Phase II IGNAZ study showing that its investigational anti-CD38 antibody felzartamab could help stabilize kidney function and reduce proteinuria in patients with IgA nephropathy (IgAN). Felzartamab’s treatment effects were also sustained through more than 18 months after the last dose.
Biogen noted that felzartamab could sustain an approximately 50% reduction in patients’ urinary protein:creatinine ratios (UPCR) through 24 months of follow-up. Felzartamab also selectively lowered IgA antibody concentrations, whereas IgG and IgM returned to baseline levels after 3 months off-treatment.
Overall, these findings suggest that felzartamab can help preserve kidney function in IgAN patients without the need for continuous dosing, according to Biogen.
IgAN is a rare autoimmune disease that develops when antibodies attack the kidneys’ glomeruli, leading to inflammation that—when left unchecked—can result in organ damage and compromise its ability to remove waste from the blood.
Uptal Patel, head of Development at HI-Bio, said in a statement that the company is “encouraged” by Saturday’s findings. Biogen, which gained ownership of felzartamab from its $1.8 billion acquisition of Hi-Bio in May 2024, is currently gearing up for the Phase III program of the antibody.
Analysts, however, were lukewarm about the readout. While BMO Capital Markets’ Evan Seigerman called IGNAZ’s findings “promising” and a validation of the value of the HI-Bio deal, he said the results were “unlikely to be significantly share moving.” Meanwhile, Jefferies’ Michael Yee wrote in an investor note that the findings were “nice” but Biogen will need to do more business development work in 2025 “to build the pipeline and get investors further engaged.”
William Blair analyst Myles Minter in a note to investors said that “there are likely outstanding questions on dosing regimen and reconciling proteinuria reductions with eGFR efficacy to answer prior to moving into pivotal studies.”
Vertex also presented IgAN data at ASN, demonstrating that an 80-mg dose of its investigational BAFF/APRIL dual antagonist povetacicept elicited a 66% mean reduction in UPCR at 48 weeks. This effect was associated with stable renal function over the same time frame, as evaluated by estimated glomerular filtration rate.
Similar efficacy figures were reported for the 240-mg povetacicept dose. Both dose levels were given subcutaneously every four weeks.
Povetacicept was well-tolerated in IgAN, with majority of the adverse events being mild or moderate in severity. There were no serious toxicities reported.
Vertex has kicked off the Phase III RAINIER study, a global trial designed to assess the safety and clinical efficacy of 80-mg povetacicept in IgAN.
In a separate investor note, Seigerman said that the povetacicept readout “continues to support Vertex’s evolving kidney portfolio” as the company tries to expand its pipeline beyond pain and cystic fibrosis. Friday’s data also “support the product’s potentially best-in-class profile,” Seigerman wrote.
Yee in an investor note said that the povetacicept‘s efficacy “continues to look promising vs competitors with its rapid and deep response.”
IgAN remains an attractive target for biopharma and in recent months several companies have succeeded in bringing innovative therapies to market. These include Travere’s Filspari, which won full approval last month, and Novartis’ Fabhalta, which the FDA granted accelerated approval in August 2024.
Minter in a note to investors said that although the IgAN space remains competitive, Vertex’s povetacicept “has maintained its potential to be a best-in-class asset” and could become a “multibillion-dollar pipeline-in-a-drug product” for autoimmune disorders.
