Clinical Trial: Androgen Reduction in Congenital Adrenal Hyperplasia, Phase 1
Study Status: Not yet recruiting
Recruit Status: Not yet recruiting
Study Type: Interventional
Official Title: A Phase 1 Multi-Center Study to Assess the Efficacy and Safety of Abiraterone Acetate as Adjunctive Therapy in Pre-Pubescent Children With Classic 21-Hydroxylase Deficiency
Brief Summary: Children with congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency tend to have elevated circulating levels of androgens, which can accelerate skeletal maturation and adversely impact adult height. Additionally, these children require supraphysiologic doses of hydrocortisone to suppress secretion of adrenal androgen precursors, and this treatment can retard linear growth. This study seeks to use oral abiraterone acetate (Zytiga)as an adjunct to approved CAH therapy (oral hydrocortisone and fludrocortisone) for pre-pubescent children with classic 21-hydroxylase deficiency in order to reduce daily requirement of hydrocortisone. In this Phase 1 study, the investigators will determine the minimum effective dose of abiraterone acetate that normalizes androstenedione levels during the 7-day Treatment Period.
Detailed Summary: Congenital adrenal hyperplasia (CAH) is an inherited inability to synthesize cortisol in the adrenal gland. More than 90% of cases are cause by deficiency of steroid 21-hydroxylase (CYP21, also termed CYP21A2, P450c21), which is a cytochrome P450 enzyme located in the endoplasmic reticulum. It catalyzes conversion of 17-hydroxyprogesterone (17-OHP) to 11-deoxycortisol, a precursor for cortisol, and progesterone to deoxycorticosterone, a precursor for aldosterone. Aldosterone deficiency may lead to salt wasting with consequent failure to thrive, hypovolemia, shock and if untreated, death in the first few weeks of life. Because patients cannot synthesize cortisol efficiently, the adrenal cortex is stimulated by corticotropin (ACTH) and overproduces cortisol precursors. Some of these precursors are diverted to sex hormone biosynthesis, which may cause signs of androgen excess including ambiguous genitalia in newborn females, rapid postnatal growth in both sexes, and accelerated skeletal maturation and decreased adult height. Patients require supraphysiologic replacement doses of glucocorticoids to suppress the adrenocorticotropic hormone (ACTH)-driven adrenal androgen synthesis. Excessive glucocorticoids are associated with excessive weight gain and slowing of linear growth. It would be desirable in pre-pubertal children to decrease the exposure to excess glucocorticoids while avoiding the adverse effects of inappropriate exposure to androgens. Abiraterone acetate is a prodrug of abiraterone, an irreversible inhibitor of 17α hydroxylase/C17, 20-lyase (cytochrome P450c17 [CYP17]), a key enzyme required for testosterone synthesis. This agent indeed suppresses adrenal androgen secretion in adult women. In this Phase 1 study, the investigators will determine the minimum effective dose of abiraterone acetate that normalizes androstenedione levels during the 7-day Treatment Period.
Sponsor: University of Texas Southwestern Medical Center
Current Primary Outcome: Normalization of serum androstenedione level [ Time Frame: 7 days ]
Original Primary Outcome: Same as current
Current Secondary Outcome:
- 17-hydroxyprogesterone levels [ Time Frame: 7 days ]
- Dihydrotestosterone levels [ Time Frame: 7 days ]
Original Secondary Outcome: Same as current
Information By: University of Texas Southwestern Medical Center
Dates:
Date Received: April 24, 2015
Date Started: December 2016
Date Completion: January 2018
Last Updated: September 7, 2016
Last Verified: September 2016
