Accretropin (somatropin rDNA Original)

Accretropin is a sustained release formulation of recombinant human growth hormone product. This protein is produced by recombinant DNA technology during fermentation in E. coli, yielding a protein containing 192 amino acids. The N-terminal amino acid, methionine, is later removed to yield a protein that is chemically and physicochemically identical to pituitary derived human growth hormone, consisting of 191 amino acids in a single polypeptide chain.

Accretropin is specifically indicated for the treatment of pediatric patients who have growth failure due to an inadequate secretion of normal endogenous growth hormone and for the treatment of short stature associated with Turner Syndrome in pediatric patients whose epiphyses are not closed.

Accretropin is supplied as a solution designed for subcutaneous administration. The recommended initial dose of the drug is as follows:
Growth Hormone Deficiency
The recommended weekly dose is 0.18 mg/kg body weight to 0.3 mg/kg (0.90 IU/kg) body weight. The dose should be divided into equal daily doses given 6 or 7 times per week subcutaneously.
Turner Syndrome
The recommended weekly dose is 0.36 mg/kg of body weight. The dose should be divided into equal daily doses given 6 or 7 times per week subcutaneously.

Failure of Accretropin to increase growth rate, particularly during the first year of therapy, should prompt assessment of compliance and evaluation of other causes of growth failure such as hypothyroidism, under-nutrition and advanced bone age.

FDA Approval
FDA approval of Accretropin was based on the results of two clinical trials.

Growth Hormone Deficiency
This single-arm, open-label, multicenter trial enrolled 44 pediatric subjects who were treated for up to 3 years with an Accretropin dose of 0.03 to 0.05 mg/kg/day (0.18 to 0.30 mg/kg/week) subcutaneously. Height SD score calculated relative to population of normally growing children increased on Accretropin treatment from -3.04 at baseline to -2.46 at one year, -2.12 at two years, and -1.78 at three years.

Turner Syndrome
This single-arm, open-label, single-center trial enrolled 37 subjects who received an Accretropin dose of 0.06 mg/kg/day subcutaneously (0.36 mg/kg/week). Height SD score calculated relative to population of Turner Syndrome patients increased on Accretropin treatment from -3.17 at baseline to -2.67 at one year, -2.43 at two years, and -2.28 at three years.

Adverse events associated with the use of Accretropin for growth hormone deficiency may include, but are not limited to, the following:

• injection site reactions
• nausea
• headache
• fatigue
• scoliosis

Adverse events associated with the use of Accretropin for Turner Syndrome may include, but are not limited to, the following:

• injection site reactions, including erythema, edema, pain, pruritis

Accretropin is a sustained release formulation of recombinant human growth hormone product. This protein is produced by recombinant DNA technology during fermentation in E. coli, yielding a protein containing 192 amino acids. The N-terminal amino acid, methionine, is later removed to yield a protein that is chemically and physicochemically identical to pituitary derived human growth hormone, consisting of 191 amino acids in a single polypeptide chain.

Davenport ML, Crowe BJ, Travers SH, Rubin K, Ross JL, Fechner PY, Gunther DF, Liu C, Geffner ME, Thrailkill K, Huseman C, Zagar AJ, Quigley CA Growth hormone treatment of early growth failure in toddlers with Turner syndrome: a randomized, controlled, multicenter trial. The Journal of Clinical Endocrinology and Metabolism 2007 Sep;92(9):3406-16

Baxter L, Bryant J, Cave CB, Milne R Recombinant growth hormone for children and adolescents with Turner syndrome. Cochrane Database of Systematic Reviews 2007 Jan 24;(1):CD003887

Lanes R, Gunczler P, Esaa S, Weisinger JR The effect of short- and long-term growth hormone treatment on bone mineral density and bone metabolism of prepubertal children with idiopathic short stature: a 3-year study. Clinical Endocrinology 2002 Dec;57(6):725-30

For additional information regarding Accretropin or short stature in pediatrics due to growth hormone deficiencies or Turner Syndrome, please visit the Accretropin webpage.