Participants underwent testicular ultrasound of left and right testes at pre-specified time points to measure TV. TV was measured as the sum of volumes of left and right testes. The linear mixed model with a fixed effect for baseline and Week 64 and a random effect for participant was used to calculate the mean change in log-transformed TV and associated 95% confidence intervals (CIs) from baseline to Week 64. The geometric mean ratio and its 95% CIs for TV were obtained by exponentiation. The ratio > 1 indicated an increase in TV from baseline.

All participants who received at least 1 dose of study treatment, who had a baseline and at least 1 post baseline TV value, had luteinizing hormone (LH) level ≤3 IU/L anytime in the study, had at least 12 weeks of Corifollitropin Alfa (CFA) and 24 weeks of CFA plus human chorionic gonadotropin (hCG) treatment, have last TV value within 4 weeks from last dose of CFA were analyzed.

An adverse event was defined as any untoward medical occurrence in a patient or clinical investigation subject administered a pharmaceutical product and which does not necessarily have to have a causal relationship with this treatment. The number of participants who experienced an AE was reported.

All participants who received at least 1 dose of study treatment were analyzed.

An adverse event was defined as any untoward medical occurrence in a patient or clinical investigation subject administered a pharmaceutical product and which does not necessarily have to have a causal relationship with this treatment. The number of participants who discontinued study treatment due to an AE was reported.

All participants who received at least 1 dose of study treatment were analyzed.

Blood samples were collected at pre-specified time points to assess anti-CFA antibodies. The percentage of participants with anti-CFA antibodies after administration of CFA were reported.

All participants who received at least 1 dose of study treatment were analyzed.

Serum Inhibin B concentration is a surrogate marker for spermatogenesis in males. Blood samples were collected at baseline and Week 64 post dose to report the mean change from baseline in serum inhibin concentration to Week 64. A mean change from baseline in serum inhibin B concentration to Week 64 was reported. A positive value indicated a higher serum inhibin concentration level.

All participants who received at least 1 dose of study treatment who had a baseline and at least 1 post baseline TV value, had LH level ≤3 IU/L anytime in the study, had at least 12 weeks of CFA and 24 weeks of CFA plus hCG treatment, have last TV value within 4 weeks from last dose of CFA and had a baseline and at least 1 post baseline inhibin value were analyzed.

Growth velocity is the rate of change in height measurement and is a marker for pubertal progress. Height was measured using a wall-mounted calibrated stadiometer. A mixed model was used to assess the overall growth velocity slope over the 36-week treatment period using the slopes estimated from an overall mixed random intercept and random slope model of height (cm) and time (yr) and age as covariates.

All participants who received at least 1 dose of study treatment, had a baseline and at least 1 post baseline TV value, had LH level ≤3 IU/L anytime in the study, had at least 12 weeks of CFA and 24 weeks of CFA plus hCG treatment, had last TV value within 4 weeks from last dose of CFA and had a baseline and post baseline height records at Week 36 were analyzed.

Growth velocity is the rate of change in height measurement and is a marker for pubertal progress. Height was measured using a wall-mounted calibrated stadiometer. A mixed model was used to assess the overall growth velocity slope over the 64-week treatment period using the slopes estimated from an overall mixed random intercept and random slope model of height (cm) and time (year) and age as covariates.

All participants who received at least 1 dose of study treatment, had a baseline and at least 1 post baseline TV value, had LH level ≤3 IU/L anytime in the study, had at least 12 weeks of CFA and 24 weeks of CFA plus hCG treatment, had last TV value within 4 weeks from last dose of CFA and had a baseline and post baseline height records at Week 64 were analyzed.

Male participants were assessed clinically for pubertal development using the TS for pubic hair (range: Tanner I-V). TS describes sexual maturity stages (no better or worse outcome) as: Tanner I: prepubertal state, Tanner II: small amount of long, downy hair with slight pigmentation at the base of the penis and scrotum, Tanner III: hair becomes more coarse and curly, and begins to extend laterally, Tanner IV: adult-like hair quality, extending across pubis but sparing medial thighs and Tanner V: hair extends to medial surface of the thigh. The number of participants in each Tanner stage at baseline and categorical change from baseline in Tanner stages to Weeks 12, 36 and 64 were reported.

All participants who received at least 1 dose of study treatment who had a baseline and at least 1 post baseline TV value, had LH level ≤3 IU/L anytime in the study, had at least 12 weeks of CFA and 24 weeks of CFA plus hCG treatment, have last TV value within 4 weeks from last dose of CFA were analyzed.

Male participants were assessed clinically for pubertal development using TS for genital growth (range: Tanner I-V). TS describes sexual maturity stages (no better or worse outcome) as: Tanner I: prepubertal (TV <1.5 ml; small penis), Tanner II: TV 1.6-6ml; skin on scrotum thins, reddens and enlarges; penis length unchanged, Tanner III: TV 6-12ml; scrotum enlarges further; penis begins to lengthen Tanner IV: TV 12-20ml; scrotum enlarges further and darkens; penis increases in length and circumference, and Tanner V: TV >20ml; adult scrotum and penis. The number of participants in each Tanner stage at baseline and categorical change from baseline in Tanner stages to Weeks 12, 36 and 64 were reported.

All participants who received at least 1 dose of study treatment who had a baseline and at least 1 post baseline TV value, had LH level ≤3 IU/L anytime in the study, had at least 12 weeks of CFA and 24 weeks of CFA plus hCG treatment, have last TV value within 4 weeks from last dose of CFA were analyzed.

Blood samples were collected at pre-specified time points (Day 1 (predose, 6-24 hours postdose after 1st dose), Day 3 (32-52 hours postdose after 1st dose), Day 5 (72-120 hours postdose after 1st dose), Day 8 (144-192 hours postdose after 1st dose), Day 11 (216-244 hours postdose after 1st dose), Day 29 (predose prior to 2nd dose; no hCG), Day 85 (predose, prior to 4th dose; no hCG), Day 169 (predose prior to 7th dose; with hCG co-administration), Day 253 (predose prior to 10th dose with hCG co-administration), Day 337 (predose prior to 13th dose; with hCG co-administration), Days 449 and 456 (postdose)) to report the mean serum concentration of CFA.

All enrolled participants in the study were analyzed.

Testicular Echogenicity was determined by evaluating the sonographic patterns obtained on testicular ultrasound of right and left testes at baseline, Week 12, Week 36 and 64. The sonographic patterns were assessed by central imaging unit by an independent radiologist and categorized as Hypoechoic (decreased echogenicity as compared to echogenicity at baseline), Isoechoic (same echogenicity as compared to echogenicity at baseline) and Hyperechoic (increased echogenicity as compared to echogenicity at baseline). The number of participants with a sonographic pattern at Weeks 12, 36 and 64 were reported.

All participants who received at least 1 dose of study treatment who had a baseline and at least 1 post baseline TV value, had LH level ≤3 IU/L anytime in the study, had at least 12 weeks of CFA and 24 weeks of CFA plus hCG treatment, have last TV value within 4 weeks from last dose of CFA were analyzed.

LH is a gonadotropin secreted from the anterior pituitary and is a marker for spontaneous puberty. Blood samples were collected at baseline, Week 12, Week 36 and Week 64 to report the mean change from baseline in LH level to Weeks 12, 36 and 64.

All participants who received at least 1 dose of study treatment who had a baseline and at least 1 post baseline TV value, had LH level ≤3 IU/L anytime in the study, had at least 12 weeks of CFA and 24 weeks of CFA plus hCG treatment, had last TV value within 4 weeks from last dose of CFA and had a baseline and post baseline LH values at Weeks 12, 36 and 64 were analyzed.

Blood samples were collected at baseline, Week 12, Week 36 and Week 64 to report the mean change from baseline in T level to Weeks 12, 36 and 64. The change from baseline in T level to Week 12, 36, and 64 could not be calculated as planned because only 2 participants had baseline T level values which were insufficient to provide the trend change from baseline in T level to Week 12, 36, and 64.

All participants who received at least 1 dose of study treatment who had a baseline and at least 1 post baseline TV value, had LH level ≤3 IU/L anytime in the study, had at least 12 weeks of CFA and 24 weeks of CFA + hCG treatment, had last TV value within 4 weeks from last CFA dose and had a baseline and post baseline T value at Week 12, 36 and 64 were to be analyzed.

Total T is a marker for progress of puberty in males. Total T levels increase during puberty as the testes respond to the gonadotropins. Blood samples were collected at baseline, Week 12, Week 36 and Week 64 post dose to report the mean change from baseline in Total T level to Weeks 12, 36 and 64. A negative value indicated a lower Total T level.

All participants who received at least 1 dose of study treatment who had a baseline and at least 1 post baseline TV value, had LH level ≤3 IU/L anytime in the study, had at least 12 weeks of CFA and 24 weeks of CFA plus hCG treatment, had last TV value within 4 weeks from last dose of CFA and had a baseline and post baseline Total T value at Week 12, 36 and 64 were analyzed.

E2 levels rise during puberty in males when some of the T secreted is aromatized. Blood samples were collected at baseline, Week 12, Week 36 and Week 64 to report the mean change from baseline in E2 level to Weeks 12, 36 and 64. A positive value indicated a higher E2 level.

All participants who received at least 1 dose of study treatment who had a baseline and at least 1 post baseline TV value, had LH level ≤3 IU/L anytime in the study, had at least 12 weeks of CFA and 24 weeks of CFA plus hCG treatment, had last TV value within 4 weeks from last dose of CFA and had a baseline and post baseline E2 value at Week 12, 36 and 64 were analyzed.

SHBG is a blood protein that controls the amount of T body tissues in males. SHBG is regulated by the ratio of T and E2 levels in addition to other factors (thyroid hormone status, dietary factors, certain diseases and medications). Blood samples were collected at baseline, Week 12, Week 36 and Week 64 to report the mean change from baseline in SHBG level to Weeks 12, 36 and 64. A negative value indicated a lower SHBG level.

All participants who received at least 1 dose of study treatment who had a baseline and at least 1 post baseline TV value, had LH level ≤3 IU/L anytime in the study, had at least 12 weeks of CFA and 24 weeks of CFA plus hCG treatment, had last TV value within 4 weeks from last dose of CFA and had a baseline and post baseline SHBG value at Week 12, 36 and 64 were analyzed.

AMH is a marker for progress of puberty in males. Blood samples were collected at baseline, Week 12, Week 36 and Week 64 to report the mean change from baseline in AMH level to Weeks 12, 36 and 64. A negative value indicated a lower AMH level.

All participants who received at least 1 dose of study treatment who had a baseline and at least 1 post baseline TV value, had LH level ≤3 IU/L anytime in the study, had at least 12 weeks of CFA and 24 weeks of CFA plus hCG treatment, had last TV value within 4 weeks from last dose of CFA and had a baseline and post baseline AMH value at Week 12, 36 and 64 were analyzed.