Pharmacokinetic and pharmacodynamic evaluation of the new prolonged-release leuprorelin acetate microspheres for injection compared with Enantone® in healthy Chinese male volunteers

Purpose To compare the pharmacokinetics, pharmacodynamics and safety of the new prolonged-release leuprorelin acetate microspheres for injection (3.75 mg) with the reference product Enantone® (3.75 mg).Method 48 healthy male volunteers were enrolled and randomly received a single 3.75 mg dose of the test drug or Enantone®.Results There were no significant differences in Cmax, AUC0-t and AUC0-48 between the test group and reference group (P > 0.05). The 90% confidence intervals of the two groups were 87.49%~112.74%, 97.15%~154.25%, and 80.85%~109.01%, respectively. Twenty-eight days after administration, both groups reached 100.0% castration level; there was no difference in the time from administration to reaching castration level between the two groups (P > 0.05); However, the difference between the two groups in the duration of castration level was statistically significant (P < 0.05). There were no major or serious adverse events, and the severity was mild to moderate.Conclusion The pharmacokinetic characteristics of leuprorelin in two groups were consistent. The two groups exhibited similar inhibitory effects on testosterone and more subjects in the test group maintained a longer castration time than those in the reference group.