Open-label, controlled, phase 2 clinical trial assessing the safety, efficacy, and pharmacokinetics of INM004 in pediatric patients with Shiga toxin-producing Escherichia coli-associated hemolytic uremic syndrome.

Background: Shiga toxin-producing Escherichia coli-associated hemolytic uremic syndrome (STEC-HUS) is a severe condition mainly affecting children. It is one of the leading causes of acute kidney injury in the pediatric population. There is no established therapy for this disease. INM004 is an anti-Shiga toxin composed of equine polyclonal antibodies. This study is aimed at assessing the safety, pharmacokinetics, and efficacy of INM004 in pediatric patients with STEC-HUS.

Methods: Phase 2, open-label clinical trial with an historical control arm. Patients in the treatment arm received two doses of INM004. The primary endpoints were the safety profile, pharmacokinetics, and efficacy (dialysis days) of INM004. Secondary endpoints included other kidney and extrarenal outcomes. Propensity score matching was used for efficacy comparisons between arms.

Results: Fifty-seven and 125 patients were enrolled in the treatment and control arm, respectively. After propensity score matching, 52 patients remained in each arm. INM004 was well-tolerated. Eight adverse events were considered possibly related, none of which were serious or severe. In the primary efficacy endpoint, patients of the treatment arm presented a non-statistically significant difference of two dialysis days. On secondary endpoints, non-statistically significant trends toward fewer patients needing dialysis and dialysis for more than 10 days, and shorter time to glomerular filtration rate normalization, were observed favoring the treatment arm.

Conclusions: INM004 showed an adequate safety profile. Efficacy non-statistically significant trends suggesting a beneficial effect in the amelioration of kidney injury were observed. These results encourage the conduction of a phase 3 study of INM004 in pediatric patients with STEC-HUS.