Corifollitropin alfa: a review of its use in controlled ovarian stimulation for assisted reproduction.

Corifollitropin alfa (Elonva®) is a fusion product of human follicle-stimulating hormone (FSH) and the C-terminal peptide of the β-subunit of human chorionic gonadotropin (hCG) produced by recombinant DNA technology. It has the same pharmacologic activity as FSH and recombinant FSH (rFSH; follitropin alfa; follitropin beta), but with a slower absorption and a longer half-life. Corifollitropin alfa is indicated as a multifollicular stimulant for women undergoing controlled ovarian stimulation using gonadotropin-releasing hormone (GnRH) antagonist-assisted reproduction protocols. In two large, randomized, double-blind, phase III trials, a single subcutaneous injection of corifollitropin alfa was no less effective as a multifollicular stimulant than seven once-daily injections of rFSH when used as part of a GnRH antagonist-assisted controlled ovarian stimulation cycle. With regard to primary endpoints, the mean number of retrieved oocytes per started cycle demonstrated that the two treatments were equivalent, and the ongoing pregnancy rate in recipients of corifollitropin alfa was noninferior to that in recipients of rFSH. The median duration of stimulation with FSH was 9 days in both treatment arms of both trials, which means that, on average, recipients of corifollitropin alfa required only 2 further days of stimulation with rFSH prior to triggering oocyte maturation with the administration of hCG. Fertilization rates were high, ranging from 66% to 68%, in recipients of corifollitropin alfa or rFSH in both trials. When used as part of a GnRH antagonist-assisted reproduction protocol, corifollitropin alfa was generally well tolerated, with a tolerability profile similar to that of rFSH. In large, pooled analyses of clinical trials, the incidence of ovarian hyperstimulation syndrome in both the corifollitropin alfa and rFSH treatment arms was consistent with that expected in the relatively young patient population. Furthermore, there were no clinically relevant differences in pregnancy complications and the incidence of infant adverse events between treatment arms. In conclusion, a single subcutaneous injection of corifollitropin alfa provides sustained multifollicular stimulation for up to a week in women undergoing controlled ovarian stimulation. Compared with seven once-daily injections of rFSH, a single injection of corifollitropin alfa achieves equivalent efficacy, and provides a well tolerated and more convenient treatment option to induce multiple follicular growth prior to assisted reproduction.