FDA Grants Priority Review for Full Approval of Tarpeyo for the Treatment of IgA Nephropathy

Rare Daily Staff

The U.S. Food and Drug Administration accepted the supplemental New Drug Application for Calliditas Therapeutics’ Tarpeyo and granted priority review.

Tarpeyo is currently approved under accelerated approval to reduce proteinuria in adults with primary IgA nephropathy at risk of rapid disease progression.

Primary immunoglobulin A nephropathy (IgA nephropathy or IgAN or Berger’s Disease) is a rare, progressive, chronic autoimmune disease that attacks the kidneys and occurs when galactose-deficient IgA1 is recognized by autoantibodies, creating IgA1 immune complexes that become deposited in the glomerular mesangium of the kidney. This deposition in the kidney can lead to progressive kidney damage and potentially a clinical course resulting in end- stage renal disease. IgAN most often develops between late teens and late 30s.

Tarpeyo is an oral, delayed release formulation of budesonide, a corticosteroid with potent glucocorticoid activity and weak mineralocorticoid activity that undergoes substantial first pass metabolism. Tarpeyo as a 4 mg delayed release capsule and is enteric coated and designed to remain intact until it reaches the ileum. Each capsule contains coated beads of budesonide that target mucosal B-cells present in the ileum, including the Peyer’s patches, which are responsible for the production of galactose-deficient IgA1 antibodies causing IgA nephropathy. It is unclear to what extent Tarpeyo’s efficacy is mediated via local effects in the ileum vs systemic effects.

“The significant eGFR treatment benefit observed across the entire study population provides further evidence that Tarpeyo can be disease-modifying, potentially significantly delaying the need for dialysis or kidney transplantation for patients at risk,” said Renee Aguiar-Lucander, CEO of Calliditas.

The sNDA is based on the full data set from the phase 3 NefIgArd clinical trial, a randomized, double-blind, multicenter study evaluating the efficacy and safety of Tarpeyo (developed under the project name Nefecon) at a once-daily dose of 16 mg, compared to placebo, in adult patients with primary IgAN on optimized RASi therapy. The trial demonstrated a statistically significant benefit of Nefecon over placebo in estimated glomerular filtration rate (eGFR) over the two-year study period, which consisted of nine months of treatment with Nefecon or placebo, followed by a 15-month follow-up period off the study drug. The data reflected treatment benefits across the entire study population.

Calliditas is also collaborating with its European commercial partner, STADA Arzneimettel, to seek full approval of Nefecon (which received conditional approval under the brand name Kinpeygo) by the European Commission in the full study population.

Photo: Renee Aguiar-Lucander, CEO of Calliditas