[Efficacy and safety of recombinant human growth hormone solution in children with growth hormone deficiency in China: a multicenter trial].

OBJECTIVE: Human growth hormone (hGH) is an essential therapeutic drug for the treatment of growth hormone (GH) deficiency (GHD). However, the process of dissolving hGH of the powder form is complicated and potentially hazardous. In the present study, we evaluated the efficacy and safety of preparation in the replacement therapy for children with GH deficiency.

METHODS: A 12-month randomized, open-label, multicenter trial was conducted in 31 previously untreated children with growth failure secondary to GH deficiency [20 boys and 11 girls, mean age (10.5 +/- 4.1) years]. An recombined human growth hormone (rhGH) solution (Iintropin AQ) was given via subcutaneous injection daily in every evening at a weekly dose of 0.25 mg/kg. The patients were followed up at 3, 6, 9, and 12 months of the treatment, and the course of treatment was 12 months. Body height was measured 3-monthly and height velocity (HV) and mean height standard deviation score (HT SDS) were calculated. Serum Insulin-like growth factor I (IGF-1), Insulin-like growth factor binding protein 3 (IGFBP-3), GH antibodies and safety parameters were assessed at the baseline and at 3-month intervals. Bone age (BA) was assessed at the baseline and the rate of skeletal maturation (DeltaBA/DeltaCA) was calculated after 6 and 12 months of rhGH treatment by a central bone age reader. Moreover, the safety of rhGH solution treatment was assessed.

RESULTS: After 12 months of liquid rhGH therapy, growth parameters were significantly increased over baseline. (1) The mean (+/- SD) height increment DeltaHT (cm) was 4.0 +/- 1.3, 7.0 +/- 2.0, 10.3 +/- 2.6 and 12.9 +/- 3.3 after 3, 6, 9, and 12 months of treatment, respectively (P < 0.01), which indicated linear growth after treatment. The GV (cm/years) was 2.7 +/- 0.9 before treatment and increased to 16.0 +/- 5.1, 14.1 +/- 4.0, 13.7 +/- 3.5, and 12.9 +/- 3.3 after treatment, suggesting that catch-up growth was significant after treatment as compared to the pre-treatment status (P < 0.01). Accordingly, post-treatment catch-up growth was obvious, significant differences were observed in HT SDS, which was -4.62 +/- 1.46 at the onset of therapy and increased significantly after the treatment to -3.80 +/- 1.53, -3.28 +/- 1.60, -2.86 +/- 1.75 and -2.47 +/- 1.86, respectively (P < 0.01). The height difference between GH deficient children and unimpaired children of the same age and gender gradually decreased after treatment, which was significantly different from that seen before treatment (P < 0.01). (2) The levels of serum IGF-1 and IGFBP-3 were increased comparably for the treatment. IGF-1 level (microg/L) was 41 +/- 64 at baseline and increased to 179 +/- 155, 202 +/- 141, 156 +/- 155 and 159 +/- 167 after 3, 6, 9, 12 months of treatment. IGFBP-3 level (mg/L) was 1540 +/- 1325 at baseline, and increased to 3891 +/- 1815, 4051 +/- 1308, 3408 +/- 1435 and 3533 +/- 1413, respectively, suggesting that with the increases in height, IGF-1, and IGFBP-3 were significantly activated to relatively high levels by the medication and reached peak values between 3 and 6 months of treatment. The levels of IGF-1 and IGFBP-3 were significantly different before and after treatment (P < 0.01). The IGF-1/IGFBP-3 molar ratio significantly increased during GH therapy (0.143 +/- 0.013 pre-therapy up to 0.240 +/- 0.055 post-therapy, P < 0.01). The IGF-1/IGFBP-3 molar ratio tended to stabilize after 3-month GH therapy. (3) The bone age assessment carried out 6 and 12 months after treatment showed that the bone maturity (DeltaBA/DeltaCA) was 1.01 +/- 0.57 and 1.07 +/- 0.75, respectively, suggesting that there was no speed-up development in the bone age. No severe adverse events were observed during the trial and the most frequent accompanying event was mild hypothyroidism.

CONCLUSIONS: rhGH solution (Iintropin AQ) is a safe and effective preparation in the replacement therapy for children with GH deficiency.