Four days from now, the US Food and Drug Administration is due to hand down its atacicept IgA nephropathy decision, ruling on whether the experimental Vera Therapeutics drug becomes the first therapy to target both BAFF and APRIL in adults with the disease. The regulator’s Prescription Drug User Fee Act target action date of 7 July 2026 caps a review built on Phase 3 data showing a 41.8 percentage point reduction in proteinuria over placebo, and the outcome is being closely watched across the nephrology community, in the UK as much as in the US.
IgA nephropathy, sometimes called Berger’s disease, is the most common primary glomerulonephritis worldwide. It develops when abnormally glycosylated IgA1 antibodies form immune complexes that deposit in the kidney’s filtering units, triggering inflammation and progressive scarring. At least half of those diagnosed go on to develop kidney failure or die within ten to twenty years, often in early adulthood, and treatments that address the underlying disease process, rather than just its downstream symptoms, have historically been scarce.
What Atacicept Does
Atacicept is a recombinant fusion protein built around the soluble TACI receptor, which binds and neutralises two cytokines, B-cell activating factor and a proliferation-inducing ligand, both central to the survival and antibody production of B-cells. By blocking BAFF and APRIL together, the drug aims to reduce production of the harmful IgA1 antibodies at their source, upstream of the kidney damage that follows. Originally developed by ZymoGenetics and later advanced by Merck Serono, the molecule has since been given to more than 1,500 patients across a range of autoimmune conditions, giving Vera Therapeutics an extensive safety database to draw on as it pursues approval in this specific indication.
The Atacicept IgA Nephropathy Data Behind the Filing
Vera’s Biologics License Application rests primarily on ORIGIN 3, a global, double-blind, placebo-controlled phase 3 trial that randomised 431 adults with IgA nephropathy to weekly subcutaneous atacicept or placebo, self-administered at home via autoinjector. A prespecified interim analysis of 203 patients, presented at the American Society of Nephrology’s Kidney Week in November 2025 and published simultaneously in the New England Journal of Medicine, found that atacicept reduced the urinary protein-to-creatinine ratio by 45.7 per cent from baseline at week 36, compared with 6.8 per cent for placebo, a between-group difference of 41.8 percentage points.
Secondary measures moved in the same direction. Levels of galactose-deficient IgA1, the aberrant antibody thought to drive the disease, fell by roughly 68 per cent versus placebo, with reductions apparent from as early as week four. Among patients who entered the trial with haematuria, 81 per cent saw it resolve on atacicept, against 21 per cent on placebo. The proteinuria benefit held consistent across subgroups defined by age, sex, race, region, baseline kidney function and background use of SGLT2 inhibitors, which is notable given how heterogeneous IgA nephropathy can be in practice.
Safety data were reassuring. Adverse events occurred in 59.3 per cent of the atacicept group against 50.0 per cent on placebo, though the large majority were mild or moderate. Serious adverse events were less frequent with atacicept than placebo across the full ORIGIN 3 analysis set, and the trial recorded no deaths and no signal of clinically significant immunosuppression, an important reassurance for a drug that dampens B-cell activity over the long term.
Why the BLA Matters Now
Vera submitted the BLA under the FDA’s accelerated approval pathway, which allows a drug for a serious condition to reach patients on the strength of a surrogate endpoint, in this case proteinuria reduction, ahead of confirmatory data on hard clinical outcomes. The application received Priority Review, alongside Breakthrough Therapy designation, reflecting the FDA’s own assessment that the drug could offer a substantial improvement over existing options.
Marshall Fordyce, Founder and Chief Executive of Vera Therapeutics, has described the treatment as offering “a distinct approach through dual targeting of BAFF and APRIL” that the company believes could help reshape the IgA nephropathy treatment landscape if it clears review.
If cleared on 7 July, atacicept would become the first approved therapy in IgA nephropathy to target both BAFF and APRIL simultaneously, distinguishing it from single-target agents such as sibeprenlimab, an APRIL-only antibody that reported broadly similar proteinuria and biomarker effects in the VISIONARY trial. It would also join a treatment landscape that already includes the non-immunosuppressive endothelin and angiotensin receptor antagonist sparsentan, which started on an accelerated pathway before converting to full FDA approval in September 2024, and a delayed-release formulation of budesonide, still under accelerated approval pending confirmatory data, alongside SGLT2 inhibitors used more broadly across chronic kidney disease. Vera is not without competition on the BAFF and APRIL front either. Vertex Pharmaceuticals’ povetacicept, a related fusion protein, was accepted for accelerated approval review in IgA nephropathy in June, with a later PDUFA date of 30 November 2026, based on interim data from the phase 3 RAINIER trial.
What an Atacicept IgA Nephropathy Approval Would Mean for the UK
Although the immediate decision sits with the FDA, UK clinicians and patients have a direct stake in the outcome. Sparsentan received an initial UK marketing authorisation from the Medicines and Healthcare products Regulatory Agency in November 2024, later converted to standard approval in April 2025, and was subsequently recommended by NICE for use across the NHS in England, while budesonide followed a similar path through the Scottish Medicines Consortium earlier this year. A positive atacicept IgA nephropathy verdict from the FDA would not, on its own, grant UK access, since the drug would still need to go through MHRA review, whether via the International Recognition Procedure or a standard application, followed by a NICE or SMC funding decision. But a US accelerated approval, backed by the ORIGIN 3 data package, would give Vera a clear regulatory and commercial foundation from which to pursue authorisation in the UK and the European Union, adding a fourth mechanism of action to a UK treatment landscape that has expanded rapidly since sparsentan’s arrival.
The Road Beyond Accelerated Approval
An accelerated approval would not be the end of the story. Confirmatory evidence on kidney function itself, rather than the proteinuria surrogate, will still be required to convert any accelerated approval into full approval. Vera announced in June that it had aligned with the FDA on bringing forward its analysis of estimated glomerular filtration rate from the ongoing ORIGIN 3 trial, now expected in the third quarter of 2026 rather than 2027. Assuming those results are positive, the company plans to submit a supplemental BLA for full approval before the end of the year, with a decision potentially following in 2027.
The review is also proceeding against a backdrop of unusual turbulence at the agency. Several senior officials departed the FDA in mid-May, prompting the appointment of new acting directors across the Center for Drug Evaluation and Research and the Center for Biologics Evaluation and Research under the agency’s acting commissioner. Regulatory professionals have voiced cautious optimism about the commitment to scientific rigour since, though the effect of months of leadership instability on review timelines and predictability more broadly remains to be seen.
For now, atacicept sits among a small cluster of high-profile FDA decisions due in the second week of July, and one of the more consequential for a disease that has historically offered patients few options beyond blood pressure control and supportive care. Further context on how such deadlines work is available in our guide to PDUFA dates and FDA approval timelines. A decision is expected on or around 7 July 2026.
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