Weekly long-acting versus daily recombinant growth hormone in late-pubertal idiopathic short stature with near-final bone age: a 12-month retrospective cohort study

Background Evidence comparing weekly long-acting growth hormone (LAGH) with daily recombinant human growth hormone (rhGH) in late-pubertal adolescents with idiopathic short stature (ISS) and near-final bone age (BA) remains limited. Methods This 12-month retrospective cohort study included 104 adolescents with ISS and near-final BA (boys ≥ 14.5 years; girls ≥ 13.0 years) initiating weekly PEGylated rhGH ( n = 48) or daily rhGH ( n = 56). Primary growth analyses included 91 patients completing 12 months on their initial regimen (43 and 48, respectively). The primary outcome was change in height standard deviation score (Δheight SDS), analyzed using ANCOVA adjusted for baseline height SDS, sex, BA, Tanner stage, and pretreatment height velocity (HV). Results Medication possession ratio was higher with weekly PEGylated rhGH (98.2% vs. 84.5%; P < 0.001). Adjusted Δheight SDS was + 0.50 versus + 0.43 (difference, + 0.07; 95% CI, 0.01–0.14; P = 0.035), and adjusted annualized HV was 7.22 versus 6.80 cm/year (difference, + 0.42 cm/year; 95% CI, 0.04–0.80; P = 0.032). BA advancement did not differ significantly (1.15 vs. 1.18 years; P = 0.624). No significant between-group differences were detected in IGF-1 profiles, metabolic outcomes, or documented adverse events. Conclusions Weekly PEGylated rhGH was associated with higher medication possession and modestly greater short-term growth than daily rhGH, without detectable differences in BA advancement or measured short-term safety outcomes. Whether these findings translate into greater final adult height remains uncertain.