OBJECTIVES: Primary IgA nephropathy in adults (IgAN) is a rare autoimmune disease that can lead to chronic kidney disease (CKD), end-stage renal disease (ESRD), and early death. Until recently, there were no approved therapies available. Nefecon is the development project name for a novel oral formulation of budesonide which is or will be marketed under other trade names. Nefecon is being investigated for IgAN in a two-part pivotal study (NefIgArd). We sought to estimate the proportion of patients achieving clinical response and the number needed-to-treat (NNT) for Nefecon compared to placebo based on data from NefIgArd Part A.

METHODS: Clinical response was based on achieving a urinary protein to creatine ratio (UPCR) < 0.8 g/g at 9- and 12-months follow-up. Based on the proportion of patients achieving clinical response, we estimated the NNT to achieve one additional clinical response for Nefecon compared to placebo. The NNT was estimated as the inverse of the absolute difference in clinical response rates between the placebo and Nefecon arms. The analysis was conducted both overall and in the subgroup of patients who had a baseline UPCR ≥ 1.5 g/g, an indicator of risk of rapid disease progression

RESULTS: The NNT at 9-months was 7.91 based on the observed clinical response rates of 34/89 (38%) and 23/90 (26%) for Nefecon and placebo, respectively. At 12-months, the observed rates of clinical response were higher in the Nefecon group (39/59 [59%]) and unchanged in the placebo group (17/66 [26%]) resulting in a lower NNT of 2.98. The NNTs in patients at who had a baseline UPCR ≥ 1.5 g/g were 5.12 at 9-months and 2.75 at 12-months which suggests a larger treatment benefit in this subgroup.

CONCLUSIONS: Nefecon demonstrated a favorable and improving clinical response rate and associated NNT compared to placebo at 9- and 12-months.