Recombinant human growth hormone plus recombinant human insulin-like growth factor-1 coadministration therapy in short children with low insulin-like growth factor-1 and growth hormone sufficiency: Results from a randomized, multicenter, open-label, parallel-group, active treatment-controlled trial

Background/Aims: Growth hormone (GH) and insulin-like growth factor-1 (IGF-1) both contribute to growth. To determine if recombinant human (rh)GH + rhIGF-1 therapy is more effective than rhGH alone to treat short stature, we assessed the efficacy and safety of coadministered rhGH + rhIGF-1 in short children with GH sufficiency and low IGF-1. Methods: In a 3-year, randomized, multicenter, open-label trial, patients with height SD score ≤-2.0 and IGF-1 SD score ≤-1.0 for age and sex, and with stimulated GH ≥10 ng/ml for age and sex, were randomized to receive (all doses in μg/kg/day): 45 rhGH alone (group A), 45 rhGH + 50 rhIGF-1 (group B), 45 rhGH + 100 rhIGF-1 (group C) or 45 rhGH + 150 rhIGF-1 (group D). Height velocity (HV) and Δ height SD score were measured. Results: The first-year HV (modified intention-to-treat population) was 9.3 ± 1.7 cm/year (group A), 10.1 ± 1.3 cm/year (group B), 9.7 ± 2.5 cm/year (group C) and 11.2 ± 2.1 cm/year (group D) (p = 0.001 for groups A vs. D). This effect was sustained, resulting in a height SD score improvement during the second and third years. Most treatment-emergent adverse events were mild and transient. Conclusion: In children with short stature, GH sufficiency and low IGF-1, coadministration of rhGH/rhIGF-1 (45/150 μg/kg) significantly accelerated linear growth compared with rhGH alone, with a safety profile similar to the individual monotherapies.