Pharmacokinetics and Pharmacodynamics of Follicle-Stimulating Hormone in Healthy Women Receiving Single and Multiple Doses of Highly Purified Human Menotrophin and Urofollitrophin.

BACKGROUND AND OBJECTIVE: Highly purified human menotrophin and urofollitrophin preparations obtained from human urine via a novel patented purification method have been tested over a timeframe of 14 years in the studies presented in this article. The objective of the studies was to investigate the pharmacokinetics and the pharmacodynamics of follicle-stimulating hormone (FSH) after single subcutaneous and intramuscular doses and multiple subcutaneous doses of the tested preparations in healthy fertile pituitary-suppressed women.

DESIGNS: We performed five open, randomised, crossover, single-dose bioequivalence and/or bioavailability studies and one open, multiple-dose, pharmacokinetics and pharmacodynamics study.

STUDY SUBJECTS AND TREATMENTS: The six studies included 121 healthy fertile women taking their usual combined oral contraceptives for 3 months before the study: Study 1: 300 international units (IU) of highly purified menotrophin as single subcutaneous and intramuscular doses. Study 2: 300 IU of highly purified menotrophin (test formulation vs. comparator) as single subcutaneous doses. Study 3: 300 IU of highly purified urofollitrophin (hp-FSH) (test formulation vs. comparator) as single subcutaneous doses. Study 4: 300 IU (2 × 150 IU vs. 4 × 75 IU) of hp-FSH as single subcutaneous doses. Study 5: 225 and 445 IU of hp-FSH as single subcutaneous doses. Study 6: daily 225 IU of hp-FSH as subcutaneous doses for 5 consecutive days.

MAIN OUTCOME MEASURES: The main outcome measures were the FSH pharmacokinetic parameters, estradiol concentrations, and the number and size of the follicles.

RESULTS: FSH after single subcutaneous and intramuscular injections of menotrophin or urofollitrophin attained a systemic peak (maximum) concentration (C max) that was on average consistent throughout the first four studies and ranged from 4.98 to 7.50 IU/L. The area under the plasma concentration-time curve (AUC) from administration to the last observed concentration time t (AUCt) ranged from 409.71 to 486.16 IU/L·h and the elimination half-life (t ½) ranged from 39.02 to 53.63 h. After multiple doses of urofollitrophin (225 IU) for 5 days, FSH attained a mean C max of 14.93 ± 2.92 IU/L and had an AUC during the time interval τ between two consecutive doses at steady state (AUCτ) of 322.59 ± 57.92 IU/L·h, which was similar to the mean AUCt after a single subcutaneous dose of 225 IU of urofollitrophin in study 5 (306.82 ± 68.37 IU/L·h).

CONCLUSIONS: In our studies, the intramuscular and subcutaneous routes of menotrophin were equivalent; both menotrophin and urofollitrophin were bioequivalent to their marketed reference; FSH kinetic parameters following injection of urofollitrophin were dose proportional and independent from the administered concentration; and multiple doses of FSH increased estradiol levels and enhanced growth of follicles with a good dose-response correlation. Local tolerability was excellent throughout the six studies.