X-linked hypohidrotic ectodermal dysplasia (XLHED) is a rare developmental disease affecting body parts derived from the embryonal ectoderm. It is caused by a broad spectrum of mutations in the ectodysplasin A gene (EDA). The main symptoms of XLHED are hypo- or anhidrosis, oligo- or anodontia, and hypotrichosis. Current treatment options are limited to the management of disease symptoms and prevention of complications. Effective corrective treatment for XLHED remains a high unmet medical need. ER004 represents a first-in-class signaling protein replacement molecule designed for specific, high affinity binding to the endogenous EDA1 receptor (EDAR). The proposed mechanism of action of ER004 is the replacement of the missing EDA1 protein in patients with XLHED. The aim of this prospective, open-label, genotype-match controlled, multicenter Phase 2 trial is to confirm the efficacy and safety results for ER004 administered intra-amniotically in a larger cohort of subjects. The target population will consist of male XLHED fetuses/subjects with EDA mutation confirmed by genetic diagnosis of a mutation in one of the maternal EDA alleles and ultrasonographic diagnosis of a significantly reduced number of fetal tooth germs, or by documented direct genetic diagnosis of a hemizygous EDA mutation. In the main study phase, efficacy and safety of the treated subjects will be assessed up to 6 months of age and safety of the mothers will be assessed up to 1 month after delivery of the child. In long-term follow-up phase, efficacy and safety of the treated subjects will be assessed up to 5 years of age. Treated subjects sweating ability will be compared to an untreated relative from his family, when available, or from a matched controlled subject from a previous natural history.
This is an open-label, prospective, genotype-match controlled for primary estimand, non randomized, multicenter, international Phase 2 clinical trial designed to investigate the efficacy and safety of ER004 administered intraamniotically as a treatment for unborn XLHED male subjects.