Effect of Growth Hormone Therapy on Height Velocity in Korean Children with Idiopathic Short Stature: A Phase III Randomised Controlled Trial

Background/Aims: The SYNERGY (Saizen® for Your New Life and Brighter Tomorrow without Growth Deficiency) study is the first randomised multi-centre, open-label study to assess the short-term efficacy and safety of this recombinant human growth hormone (r-hGH) preparation for prepubertal children with idiopathic short stature in South Korea. Methods: The SYNERGY study (ClinicalTrials.gov NCT01746862) was conducted at 9 centres throughout South Korea between December 2012 and March 2015. The primary endpoint was difference in height velocity from baseline to 6 months in the treatment and control arms. Results: 97 children were screened; 90 were randomly assigned: 60 children to 0.067 mg/kg/day r-hGH for 12 months (treatment) and 30 children to 6 months of no treatment followed by 0.067 mg/kg/day r-hGH for 6 months (control). The 6-month mean height velocity in the treatment group increased from 5.63 cm/year (SD 1.62) to 10.08 cm/year (SD 1.92) (p < 0.0001) and from 4.94 cm/year (SD 1.91) to 5.92 cm/year (SD 2.01) (p = 0.0938) in the control group (between-group difference 3.47 cm/year, 95% CI 2.17-4.78; p < 0.0001). Adherence was > 90% throughout the study. The safety profile was consistent with that already known for r-hGH. Conclusion: Treatment with r-hGH in the SYNERGY study demonstrated a statistically significant increase in height velocity at 6 months.