Biosynthetic Human Growth Hormone in the Treatment of Growth Hormone Deficiency

ABSTRACT. A total of 309 previously untreated children with growth hormone deficiency (GHD) (219 boys, 90 girls; mean age 8.4 ± 3.9 years, range 1.5‐19 years) were treated for up to 3 years in an ongoing trial designed to examine the long‐term efficacy and safety of biosynthetic somatropin (rhGH). The children were treated with rhGH, 0.06 mg/kg (0.16 IU/kg) three times weekly. In the prepubertal children, the mean height velocity increased during the first year from 3.8 ± 1.8 cm/year to 8.9 ± 2.2 cm/year (n = 188). During the second and third years, their height velocities were 7.1 ± 1.1 (n = 147) and 6.3 ± 1.2 cm/year (n ‐ 64), respectively. The height velocity SDS increased from ‐2.5 ± 1.9 before treatment to 3.1 ± 2.6 during the first year of treatment in the prepubertal children. The mean pretreatment height velociity in those with idiopathic GHD (3.8 ± 1.6 cm/year) did not differ from that in children with organic GHD (3.8 ± 2.3 cm/year). In addition, the height velocities during the first year of therapy did not differ significantly with respect to the aetiology of GHD. For the children who entered puberty during the study, the mean height velocity increased from 3.0 ± 1.7 cm/year before treatment to 8.4 ± 2.3 cm/year during the first year of rhGH therapy. In the first year, the height velocity of children with a bone age of less than 5 years (9.4 ± 2.3 cm/year) was significantly greater than that in children with a bone age of 5‐10 years (8.4 ± 1.8 cm/year) or greater than 10 years (7.8 ± 2.2 cm/year: p= 0.001). However, the increase in height velocity above the pretreatment level did not differ between bone age groups (p= 0.13). During the study, the height SDS improved from ‐3.4 ± 1.4 before treatment to ‐2.1 ± 1.1 by the end of year 3. At the start of rhGH therapy, only 38 out of 309 (12.3%) children had heights above ‐2 SD, but by the end of the 3 years, 44 out of 99 children (44.4%) had heights above that level. Antibodies to GH were detected in 8 out of 304 children (2.6%), but none of these children showed attenuated growth as a result. The results of this ongoing study confirm that rhGH is a safe and effective therapy in children with GHD.