Comparative pharmacokinetic and pharmacodynamic evaluation between a new biosimilar and reference recombinant human growth hormone.

OBJECTIVE: To extend available dosing options in the treatment of growth hormone deficiency, a comparative pharmacokinetic and pharmacodynamic phase-1 clinical study involving subcutaneous administration of growth hormone was conducted.

DESIGN: The test formulation (biosimilar recombinant human growth hormone; r-hGH; Somatotropin) and reference formulation (Genotropin®) were tested in 38 adult healthy subjects after their subcutaneous administration of 12.8IU in an open label, single dose, randomized, two period cross over study separated with a washout period of 11days. Endogenous growth hormone release was suppressed by a continuous Octreotide infusion up to 24h after r-hGH administration. All the subjects were evaluated for local tolerance using Wong-Baker Faces pain rating scale and an injection site reaction (ISR) score. Detection of serum levels of r-hGH, insulin-like growth factor-1 (IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3) was done by suitable validated bio-analytical methods. Assessment of bioequivalence for pharmacokinetic parameters was done using log-transformed area under the curve (AUC) and maximum concentration (Cmax ) for r-hGH. The pharmacodynamic assessment was done by comparing the area under the effect-time curve (AUEClast) and maximum measured effect concentration (Emax ) of IGF-1 and IGFBP-3.

RESULTS: The biosimilar formulation of recombinant human growth hormone fulfilled the predefined bioequivalence criteria for pharmacokinetic and pharmacodynamic parameters.

CONCLUSION: The new biosimilar recombinant human growth hormone bears the potential to become an alternative option for the treatment of growth hormone deficiency.