Elonva® (corifollitropin alfa injection) has been approved in the EU for controlled ovarian stimulation (COS) in combination with a GnRH antagonist for the development of multiple follicles in women participating in an assisted reproductive technology programme. The drug is designed as a sustained follicle stimulant with the same pharmacodynamic profile as rFSH, but with a markedly prolonged duration of FSH activity. The manufacturers state that due to its ability to initiate and sustain multiple follicular growth for an entire week, a single subcutaneous injection of the recommended dose may replace the first seven injections of any daily rFSH preparation in a COS treatment cycle.