The treatment resulted in a significant reduction of proteinuria from baseline in 34% of trial participants.
The US Food and Drug Administration had granted approval for budesonide (TARPEYO) delayed release capsules to reduce proteinuria in adults with primary immunoglobulin A nephropathy (IgAN) at risk of rapid disease progression, generally a urine protein-to-creatinine ratio (UPCR) of at least 1.5g/g.
The approval, awarded to Calliditas Therapeutics AB, was awarded under an accelerated approval, which was based on investigators achieving the primary endpoint of the reduction in proteinuria in Part of the NeflgArd pivotal phase 3 trial. The trial is an ongoing, randomized, double-blind, placebo-controlled, multicenter study aimed at evaluating budesonide 16 mg once daily in comparison with placebo in adult patients with primary IgAN.
The effect of the study drug was assessed in patients with biopsy-proven IgAN, eGFR at least 35 ml/min/1.73 m2, and proteinuria, defined as either at least 1 g/day or UPCR of at least 0.8 g/g who were on a stable dose of maximally-tolerated RAS inhibitor therapy.
Of the 97 patients taking the drug, 34% saw a significant reduction in proteinuria from baseline, compared to 5% with RASi alone (n = 102) at 9 months. The treatment effects at 9 months were consistent across key subgroups, including key demographic and baseline disease characteristics.
Despite the approval, it is currently unknown whether or not the treatment slows kidney function decline in patients with IgAN and continued approval could ultimately based on verification and description of clinical benefit in a confirmatory clinical trial.
"We are very excited to bring the first and only FDA-approved treatment to reduce proteinuria in IgAN to market," said Renée Aguiar-Lucander, Chief Executive Officer of Calliditas, in a statement. "TARPEYO represents an FDA approved product to help these patients who are at risk of rapid disease progression."
For safety, the most common adverse reactions were hypertension, peripheral edema, muscle spasms, acne, dermatitis, weight increase, dyspnea, face edema, dyspepsia, fatigue, and hirsutism.