Efficacy and safety of Samtropin™ recombinant human growth hormone; a double-blind randomized clinical trial

BACKGROUND: Recombinant human growth hormone (rhGH) can increase the growth rate in growth hormone deficient children (GHD). In this randomized clinical trial, we compared the efficacy and side effects of an Iranian brand; Samtropin with Norditropin. METHODS: The GHD children were randomly treated either with standard dose of Samtropin or Norditropin rhGH for one year. Upstanding height, height standard deviation score (HSDS), growth velocity (GV), serum levels of insulin like growth factor-1 (IGF-1), and bone age (BA) were determined before and during one year treatment concomitant side effects of treatment. RESULTS: We evaluated 22 subjects; 12 on Samtropin and, 10 on Norditropin. In each group, mean age was 12 yr and 50% of them were male. The mean differences in height, HSDS, IGF-1 and BA by Norditropin before and after 12 months were 8.8 cm, 0.5, 49 ng/ml and 2.8 yr, respectively. These measures by Samtropin were 9.1 cm, 0.6, 133 ng/ml, and 1.7 yr, respectively without any significant difference. The mean of GV by Samtropin was 9.1 vs. 8.8 cm by Norditropin without significant difference. Since the efficacy of Samtropin was found to be similar to Norditropin after 12 months; we switched to use only Samtropin for the next 12 months. The mean differences in height, HSDS, GV and BA in 20 children between months 12 and 24 were 7.0 cm, 1.6, 2.1 cm/yr and 1.0 yr, respectively (P < 0.001). We also found a non-significant decrease in IGF-1 levels. No side effects were observed. CONCLUSIONS: We need to conduct a post marketing surveillance with a large sample size in order to confirm our findings. TRIAL REGISTRATION: Registration code number in the Iranian Registry of Clinical Trials (IRCT): IRCT1138901181414N11.