Congenital Adrenal Hyperplasia

November 13, 2017

Millendo Therapeutics reported announced positive topline results from a phase II proof-of-concept study of ATR-101 in classic congenital adrenal hyperplasia (CAH). The trial was a multicenter, single-blind, multiple dose study that assessed the efficacy and safety of orally-administered ATR-101 in addition to corticosteroids in patients with classic congenital adrenal hyperplasia resulting from 21-hydroxylase deficiency. The study, which assessed five escalating doses, alternated between two weeks of treatment with ATR-101 and two weeks with placebo to determine the effects of ATR-101 on adrenal steroids. In the study, seven of the first 10 patients demonstrated a clear biological effect as measured by reductions in 17-hydroxyprogesterone (17-OHP), a key measure of disease control. Based on the trial results, Millendo ended the trial early and the FDA has granted orphan drug status to ATR-101 in this indication. Mean reductions in 17-OHP were observed at all ATR-101 doses while mean increases were observed during all placebo treatments. Two patients experienced a reduction in 17-OHP levels to ≤2x ULN, the primary endpoint, a result consistent with the short duration of treatment (two weeks/dose level) and high baseline levels. ATR-101 was well-tolerated at all dose levels. Separately, Millendo has decided to discontinue development of MLE4901 after assessment of the clinical risks and benefits of the program.