Growth hormone (GH) has been used to treat GH deficiency since the late 1950s, and recombinant GH has been available since 1985. GH is also approved to treat non-GH-deficient short stature, such as that seen in
Turner syndrome,
chronic renal insufficiency,
Prader-Willi syndrome, children who are small for gestational age, and idiopathic short stature. There has been interest in using recombinant
insulin-like growth factor I (
IGF-I) to treat short stature, either alone or in combination with its
binding protein, IGF binding protein (IGFBP)-3 (
SomatoKine).
IGF-I increases growth velocity in children with IGF deficiency, either as a result of
growth hormone insensitivity syndrome (GHIS) or
IGF-I gene deletion. However, there have been adverse events, particularly
hypoglycemia, reported with administration of unbound
IGF-I. In addition, the serum half-life of unbound
IGF-I is shorter when administered to patients with GHIS, who have low serum concentrations of its primary
binding protein IGFBP-3 than when administered to healthy individuals or to patients with an
IGF-I gene deletion (who have normal levels of
IGFBP-3).
SomatoKine was developed to prolong the half-life and to counteract acute adverse events (particularly
hypoglycemia) associated with
IGF-I administration.
SomatoKine appears to have a longer half-life in patients with GHIS than unbound
IGF-I and fewer adverse events (including
hypoglycemia) have been reported when administered to patients with diabetes.