Effect of krn23, a Fully Human anti-fgf23 Monoclonal Antibody, on Rickets in Children with X-linked Hypophosphatemia (xlh): 40-week Interim Results from a Randomized, Open-label Phase 2 Study

Purpose: In patients with XLH, high circulating FGF23 induces renal phosphate (Pi) wasting, hypophosphatemia, rickets, and short stature. Current treatment with oral phosphate/active vitamin D is suboptimal in many patients. Methods: In a Phase 2 study, we randomized 52 children with XLH (ages 5-12 years, ≤Tanner 2) to receive KRN23 subcutaneously, either biweekly …