Vera Therapeutics, Inc. announced the Phase 2b ORIGIN clinical trial of atacicept in patients with immunoglobulin A nephropathy (IgAN) met its primary endpoint. Atacicept is the Company's potential best-in-class, disease-modifying dual inhibitor of the cytokines B lymphocyte stimulator (BLyS) and a proliferation-inducing ligand (APRIL). ORIGIN is a multinational, randomized, double-blind, placebo-controlled clinical trial (n=116) evaluating the efficacy and safety of atacicept in patients with IgAN who continue to have persistent proteinuria and remain at high risk of disease progression despite available ACE or ARB therapy.

The primary endpoint analysis, change in proteinuria as evaluated by urine protein creatinine ratio (UPCR) at week 24 of the pooled 75/150 mg dose groups, achieved statistical significance and showed a 31% mean reduction versus baseline (p=0.037 versus placebo). Statistical significance was also achieved in the individual 150 mg dose group with a 33% mean reduction in proteinuria versus baseline (p=0.047 versus placebo) and the all-atacicept group versus placebo. A trend towards further reductions in proteinuria was observed in the all-atacicept group versus placebo with 38% of patient data available at Week 36.

The exploratory endpoint analysis, change in estimated glomerular filtration rate (eGFR), showed stabilization in the all-atacicept group through Week 24. Atacicept robustly reduced galactose-deficient IgA1 (Gd-IgA1) from baseline through 24 weeks. Safety results indicated that atacicept was generally well-tolerated and were consistent with the previously observed safety profile of atacicept, including a 1% discontinuation rate due to adverse events (AEs) and comparable rates of infection compared to placebo.

Serious treatment-emergent AEs were observed in 2% of patients in all atacicept arms and in 9% of patients in the placebo arm. These results build upon the prior integrated analysis of atacicept in randomized, double-blind, placebo-controlled clinical trials in over 1,500 patients to date – in which atacicept was well-tolerated. As a result of these positive data, Vera plans to advance atacicept into pivotal Phase 3 development in the first half of 2023, subject to and following discussions with the U.S. Food and Drug Administration.

The full data sets from the ORIGIN clinical trial will be presented at a future medical meeting.