Calliditas Announces Positive NefIgArd Open Label Extension Results

Calliditas Therapeutics AB (Nasdaq: CALT, Nasdaq Stockholm: CALTX) (“Calliditas”) today announced that the global open-label extension (OLE) study to the Phase 3 NefIgArd study showed a treatment response consistent with the NefIgArd study across endpoints of urine protein to creatinine ration (UPCR) and estimated glomerular filtration rate (eGFR) at 9 months across all IgAN patients, including those who had previously received Nefecon in the NefIgArd study.

NefIgArd was a global, Phase 3, randomized, double-blind, placebo-controlled, multicenter study designed to evaluate the efficacy and safety of Nefecon 16 mg once daily vs placebo in adult patients with primary IgAN as an addition to optimized RASi therapy. Patients were randomized 1:1 to receive 16 mg/day of Nefecon or matching placebo for 9 months, followed by a 15-month observational follow-up period without the study drug. The NefIgArd study achieved both its primary and key secondary endpoints and was the basis for full approval by the FDA in December 2023. The full data set was published in The Lancet.

The OLE study was designed to provide 9 months of treatment with Nefecon for all patients who completed the NefIgArd study and who at that time had > 1g/g of proteinuria over 24h and > 30 ml/min of eGFR. All enrolled OLE patients continued on optimized RAS inhibitor therapy (ACEs and/or ARBs) and were treated for 9 months with Nefecon 16mg per day, with a follow-up visit three months after completion of treatment.  Primary assessment was based on UPCR and eGFR at 9 months.  A total of 119 patients were enrolled, of whom 45 had previously had active treatment. 

Topline data from the OLE study showed that the treatment response was consistent with the NefIgArd study's findings regarding the endpoints of UPCR and eGFR at nine months across all patients, irrespective of whether they had previously been treated with Nefecon or with placebo.  The safety data after 9 months of treatment or retreatment with Nefecon in patients who completed the NefIgArd study were consistent with previously reported safety data.

“It is exciting to see these results on both proteinuria reduction and eGFR stabilization at 9 months across all patients irrespective of previous treatment regimen in the Phase 3 trial,”, said CEO Renée Aguiar-Lucander. “These topline results support the study thesis that the response to retreatment with Nefecon was unaffected by previous treatment cycles. We look forward to presenting data at the upcoming ERA EDTA symposium.”