Current clinical trials with authentic recombinant somatropin in Japan.

A total of 25 children with hGH deficiency were treated with recombinant somatropin, 0.5 IU/kg/week i.m. for approximately 12 months in a multicentre study. Sixteen patients were previously untreated with any hGH preparation (naïve group) and 9 patients had been treated with pituitary hGH for 4-42 months (previously treated group). The height gain after 12 months with the present treatment was 7.7 +/- 1.8 cm/year in the naïve group and 5.8 +/- 1.0 cm/year in the previously treated group. Using the criteria proposed by the Foundation for Growth Science in Japan, recombinant somatropin treatment was effective in 15 of 16 patients (93.8%) of the naïve group and in all of the 9 patients (100%) in the switched group. Anti-hGH antibody was observed in none of 9 patients in the previously treated group throughout the study period. It was observed in only 2 of 16 patients after 6 months of treatment and 1 of 16 patients after 12 months of treatment in the naïve group. No side-effects or abnormalities in laboratory findings were observed.