Urofollitropin

Urofollitropin contains a highly purified preparation of urinary FSH extracted from the urine of postmenopausal women. FSH stimulates ovarian follicular growth and development as well as gonadal steroid production in women who do not have primary ovarian failure.

The isoform composition of the highly purified FSH in urofollitropin displays more basic isoforms than other urofollitropin preparations, and is similar to that observed for recombinant FSH preparations. According to data from clinical trials, the pharmacodynamic responses associated with urofollitropin treatment do not differ from those associated with recombinant FSH when administered by the same route. After SC administration, similar follicle response, peak oestradiol levels, number of oocytes retrieved and number of mature oocytes have been found with urofollitropin and recombinant FSH, without differences in total FSH dose or duration of treatment.

Treatment with urofollitropin is usually followed by administration of hCG to induce final follicle maturation and ovulation.

Following single doses of SC administration of urofollitropin maximum FSH concentrations were reached within 21 hours. Steady-state was observed after 4 to 5 days. After 7 days of repeated administration, the maximum FSH concentrations were attained at 10 hours after injection.

Following single doses of SC administration of urofollitropin, mean elimination half-life of FSH was 41 hours. After 7 days of repeated administration, the mean elimination half-life of FSH was 30 hours for the SC route.

After 7 days of dosing with urofollitropin SC, FSH C_max was 11.1 IU/L and steady state FSH AUC was 235 IU/L*h.

The pharmacokinetics of urofollitropin in patients with renal or hepatic impairment has not been investigated.

Preclinical data reveal no special hazard for humans based on conventional studies of cardiovascular safety pharmacology, single and repeat dose toxicity, and local tolerance.

Impaired fertility was observed in rats which were treated with high doses of recombinant follitropin for prolonged time. Repeat dose toxicity studies in rats and dogs have demonstrated that high doses of urofollitropin have the potential to impair fertility due to follicular atresia and cysts in the ovaries.