Corifollitropin alfa

Corifollitropin alfa is a long-lasting single injection fusion protein which lacks luteinizing hormone (LH) activity. Only one injection is needed for the first 7 days, which replaces the first 7 daily injections of traditional follicle stimulating hormone (FSH). It is a follicle-stimulation hormone (human α-subunit reduced), a combination of follicle stimulation hormone (human β-subunit reduced) fusion protein with 118-145-chorionic gonadotropin (human β-subunit). Frequent, repetitive injections increase stress and error rates, and are often a burden for women, leading to therapy noncompliance.

The agent comprises an alpha-subunit, which is identical to that of FSH, and a beta-subunit, which is produced by the fusion of the C-terminal peptide from the beta-subunit of chorionic gonadotropin to the beta-subunit of FSH.

Corifollitropin alfa serves as a sustained follicle stimulant that has similar pharmacological effects to recombinant follicle stimulating hormone (rFSH), however, with a relatively long elimination half-life, resulting in a longer duration of action. This is achieved using site-directed mutagenesis and gene transfer techniques to create a glycoprotein that consists of an α-subunit that is identical to human follicle stimulating hormone (FSH) noncovalently bound to a β-subunit comprised of a complete β-chain of human FSH elongated by the carboxyterminal peptide of the β-subunit of human chorionic gonadotrophin (hCG). This unit interacts with the FSH receptor to stimulate the release of oocytes.

Corifollitropin alfa does not demonstrate any intrinsic LH/hCG activity.