The ongoing pregnancy rate, the primary endpoint of this non-inferiority trial, obtained in the 150mcg corifollitropin alfa treatment arm (38.9% per started cycle) was similar to that achieved in patients receiving 200 IU recombinant FSH (follitropin beta) (38.1% per started cycle). The number of oocytes retrieved (co-primary endpoint) was within the limits of clinical equivalence, and the estimated difference of +1.2 was in favor of the corifollitropin alfa 150mcg treatment arm.
Engage was a non-inferiority, double-blind fertility trial designed to compare corifollitropin alfa 150mcg to 200 IU follitropin beta. A total of 1,509 patients at 34 IVF clinics in North America and Europe were randomized to receive either corifollitropin alfa 150mcg or a daily dose of 200 IU recombinant FSH, followed by recombinant FSH (maximum 200 IU/day) from stimulation day eight onward.
The primary endpoint was ongoing pregnancy rate assessed at 10 weeks or more after embryo transfer. The number of oocytes retrieved was the co-primary endpoint. The incidence of ovarian hyperstimulation syndrome (OHSS) was similar between both groups, seven percent in the corifollitropin alfa group (1.9% severe) and 6.3% in the follitropin beta group (1.3% severe).
Corifollitropin alfa is being developed as a potential treatment in controlled ovarian stimulation for the development of multiple follicles and pregnancy in women participating in an assisted reproductive technology program.