Corifollitropin alfa doses based on body weight: clinical overview of drug exposure and ovarian response.

Corifollitropin alfa is a new recombinant gonadotrophin with a different pharmacokinetic profile but similar pharmacodynamic properties to conventional recombinant FSH. A single dose of corifollitropin alfa sustains multiple follicular development during the first 7 days of ovarian stimulation. This review is based on results of phase II and III trials testing the selected dose of 150 μg corifollitropin alfa in subjects >60 kg and 100 μg in subjects ≤60 kg. Exposure to corifollitropin alfa is inversely related to bodyweight. The selected doses of 100 and 150 μg in subjects weighing ≤60 and >60 kg, respectively, provide, on average, equal drug exposure producing similar ovarian responses in terms of the number of growing follicles, serum oestradiol, inhibin B and number of oocytes retrieved. Clinicians treating IVF patients with corifollitropin alfa should alter their treatment paradigm as a lower or higher dose than recommended according to body weight does not affect the ovarian response, which depends mainly on the ovarian reserve. After decades of daily dosing with FSH preparations, corifollitropin alfa allows a simpler IVF treatment regime with fewer injections. Successful use of corifollitropin alfa requires assessment of patient suitability and dosing before the start of stimulation.