NPSP558 is the company’s bioengineered replica of human parathyroid hormone (rhPTH 1-84), which received orphan drug status for the treatment of hypoparathyroidism.
REPLACE was a 28-week, double-blind, placebo-controlled study.
During the course of the study, 53% (48/90) of NPSP558-treated patients achieved the primary endpoint versus 2% (1/44) of placebo-treated patients.
The primary efficacy endpoint included 50% or greater reduction in oral calcium supplementation and active vitamin D therapy and a total serum calcium concentration that was normalized or maintained compared to baseline after 24 weeks of treatment.
At week 24, 43% of patients treated with NPSP558 were able to achieve independence from active vitamin D therapy and a calcium supplementation dose of 500 mg/day or less, as compared to 5% for patients treated with placebo.