Credit: Vera Therapeutics

Investigators are beginning a phase 3 trial for atacicept as a treatment for patients with IgA nephropathy (IgAN).¹

Vera Therapeutics announced the results of the ORIGIN phase 2b trial during the annual European Renal Association (ERA) Congress in Milan, Italy and said they will soon be initiating patients during the phase 3 trial.

Atacicept

The treatment is an investigational recombinant fusion protein that contains the soluble transmembrane activator and calcium-modulating cyclophilin ligand interactor (TACI) receptor that binds to cytokines B lymphocyte stimulator (BLyS) and a proliferation-inducing ligand (APRIL).

In the upcoming multinational, randomized, double-blind, placebo-controlled clinical trial, the investigators will evaluate the efficacy and safety of atacicept 150 mg in patients with IgAN who continue to have persistent proteinuria and remain at a high risk of disease progression despite optimized angiotensin converting enzyme inhibitor (ACEi) or angiotensin II receptor blocker (ARB) therapy.

The main purpose of the upcoming trial will be to determine the effect of the drug on proteinuria and preservation of renal function compared to placebo in patients with IgAN.

The study will include a 4-week screening period, a 104-week double-blind treatment period, a 52-week open-label extension, and 26 weeks of follow-up.

Each participant will be randomized to either treatment with atacicept 150 mg once weekly subcutaneous injections (n = 188) or placebo once weekly subcutaneous injections (n = 188) for 104 weeks.

Endpoints

The investigators will seek primary endpoints of the change in proteinuria, evaluated by urine protein to creatinine ratio (UPCR) at week 36. They will also look at various secondary endpoints of the annualized rate of change in estimated glomerular filtration rate (eGFR) up to week 104, the change in Gd-IgA1, change in eGFR up to week 52, and time from randomization to first occurrence of composite kidney failure endpoint event.

In the phase 2b ORIGIN trial, the investigators found the treatment met the primary endpoint of a statistically significant reduction in mean proteinuria compared to baseline at week 24.

“Building upon positive data from our Phase 2b trial that show atacicept’s best-in-class potential, initiation of the pivotal ORIGIN 3 trial is a crucial milestone in the advancement of its clinical development,” said Marshall Fordyce, MD, Chief Executive Officer of Vera Therapeutics, in a statement. “Our Phase 2 results have shown that atacicept targets the source of IgA nephropathy and improves kidney function as measured by statistically and clinically significant reductions in proteinuria. As we enroll this pivotal Phase 3 trial, we plan to share longer term Phase 2 results later in 2023 and 2024.”

The Disease

IgAN, which is also called Berger’s disease, is a progressive autoimmune disease of the kidney driven by the production of immunogenic galactose-deficient IgA1. This triggers autoantibodies that can lead to the formation of pathogenic immune complexes that become trapped in the kidney’s glomeruli and causes inflammation and progressive damage.

Up to 50% of patients with IgAN are at risk of developing end-stage renal disease (ESRD) or kidney failure.

References:

Vera Therapeutics. (2023, June 7). Vera Therapeutics initiates pivotal phase 3 (origin 3) clinical trial of ATACICEPT for the treatment of IGA nephropathy (IgAN). GlobeNewswire News Room. https://www.globenewswire.com/en/news-release/2023/06/07/2683689/0/en/Vera-Therapeutics-Initiates-Pivotal-Phase-3-ORIGIN-3-Clinical-Trial-of-Atacicept-for-the-Treatment-of-IgA-Nephropathy-IgAN.html