Corifollitropin Alfa Combined With Human Chorionic Gonadotropin in Adolescent Boys With Hypogonadotropic Hypogonadism.

CONTEXT: Adolescent males with hypogonadotropic hypogonadism (HH) have traditionally been treated with exogenous testosterone (T) or human chorionic gonadotropin (hCG) to produce virilization; however, those modalities do not result in growth of the testes and may promote premature maturation and terminal differentiation of Sertoli cells prior to their proliferation, which may impact future fertility. Another option is to use gonadotropins in those individuals to induce testicular growth, proliferation and maturation of Sertoli cells, and production of endogenous T with consequent virilization. OBJECTIVE: We examined the efficacy and safety of corifollitropin alfa (CFA) combined with hCG for the induction of testicular growth and pubertal development in adolescent boys with HH. METHODS: This was a 64-week, multicenter, open-label, single-group study of CFA in adolescent boys, aged 14 to younger than 18 years, with HH. Seventeen participants initiated a 12-week priming period with CFA (100 µg if weight ≤ 60 kg, or 150 µg if weight > 60 kg) given subcutaneously once every 2 weeks, after which they entered a 52-week combined treatment period with CFA, once every 2 weeks, and subcutaneous hCG, twice-weekly (hCG dose adjusted between 500 IU and 5000 IU to keep total T and estradiol levels within protocol-specified ranges). The primary efficacy end point was change from baseline in testicular volume (TV), measured as the sum of volumes of left and right testes by ultrasound. RESULTS: After 64 weeks of therapy with CFA/CFA combined with hCG, geometric mean fold increase from baseline in TV was 9.43 (95% CI, 7.44-11.97) (arithmetic mean of change from baseline at week 64, 13.0 mL). Hormonal, Tanner stage, and growth velocity changes were consistent with initiation and progression of puberty. Treatment was generally well tolerated. No participant developed anti-CFA antibodies. CONCLUSION: Treatment of adolescent boys with HH with CFA alone for 12 weeks followed by CFA combined with hCG for 52 weeks induced testicular growth accompanied by pubertal progression, increased T, and a pubertal growth spurt (EudraCT: 2015-001878-18).