Background: This international, Phase 3, open-label extension trial evaluated the long-term safety and efficacy of once-weekly lonapegsomatropin in children with growth hormone deficiency (GHD).Methods: Conducted across 63 sites (15 countries), the enliGHten trial enrolled children with GHD who previously participated in a Phase 3 lonapegsomatropin trial (heiGHt or fliGHt). Participants received subcutaneous injections of lonapegsomatropin dosed at 0.24 mg hGH/kg/week. Safety was monitored through adverse events, local tolerability, hormone levels, and metabolic parameters. Efficacy was evaluated through annualized height velocity (AHV), change in height standard deviation score (SDS), and IGF-1 SDS. Results: Lonapegsomatropin demonstrated sustained efficacy with mean height SDS (-0.39 at year 4, n = 298) approaching the mean for average stature children (height SDS=0) over time. Eighty-one participants completed treatment for pediatric GHD during the trial, and 48 (59.3%) of these met or exceeded their average parental height SDS at their last visit. For the full population, mean values of weekly average IGF-1 remained within 0 to 2 SDS throughout the trial. Growth was maintained throughout pubertal development and the dose remained stable throughout the trial. Adverse events were mostly mild or moderate and remained consistent with prior reports of daily somatropin with no evidence of accelerated skeletal maturation or safety signals associated with anti-drug antibodies. Conclusion: Treatment of pediatric GHD with lonapegsomatropin in the enliGHten trial provided robust growth outcomes and maintained a safety profile comparable to daily GH in a population that included a broad range of pubertal status.

Background: This international, Phase 3, open-label extension trial evaluated the long-term safety and efficacy of once-weekly lonapegsomatropin in children with growth hormone deficiency (GHD).Methods: Conducted across 63 sites (15 countries), the enliGHten trial enrolled children with GHD who previously participated in a Phase 3 lonapegsomatropin trial (heiGHt or fliGHt). Participants received subcutaneous injections of lonapegsomatropin dosed at 0.24 mg hGH/kg/week. Safety was monitored through adverse events, local tolerability, hormone levels, and metabolic parameters. Efficacy was evaluated through annualized height velocity (AHV), change in height standard deviation score (SDS), and IGF-1 SDS. Results: Lonapegsomatropin demonstrated sustained efficacy with mean height SDS (-0.39 at year 4, n = 298) approaching the mean for average stature children (height SDS=0) over time. Eighty-one participants completed treatment for pediatric GHD during the trial, and 48 (59.3%) of these met or exceeded their average parental height SDS at their last visit. For the full population, mean values of weekly average IGF-1 remained within 0 to 2 SDS throughout the trial. Growth was maintained throughout pubertal development and the dose remained stable throughout the trial. Adverse events were mostly mild or moderate and remained consistent with prior reports of daily somatropin with no evidence of accelerated skeletal maturation or safety signals associated with anti-drug antibodies. Conclusion: Treatment of pediatric GHD with lonapegsomatropin in the enliGHten trial provided robust growth outcomes and maintained a safety profile comparable to daily GH in a population that included a broad range of pubertal status.