Corifollitropin Alfa N02 versus Recombinant FSH for Ovarian Stimulation: A Phase 3 Trial and Safety Study in Chinese Women

Research Question What is the efficacy and safety of Corifollitropin alfa N02, a long-acting follicle-stimulating hormone (FSH) analog, in comparison with daily recombinant FSH (rFSH) for ovarian stimulation in Chinese women? Design In this double-blind, multicenter trial (NCT06091436), 474 women aged 20-39 years with normal ovarian reserve were randomized 1:1 to a single subcutaneous dose of Corifollitropin alfa N02 (100/150 μg; n=238) or daily rFSH (150/225 IU; n=236) for the first week of stimulation, followed by individualized daily rFSH from day 8. The primary objective was non-inferiority in the number of oocytes retrieved (margin: -3). Results The Corifollitropin alfa N02 group demonstrated non-inferiority, with a mean of 12.1 oocytes retrieved versus 10.9 in daily rFSH (estimated difference: 1.2; 95% CI: 0.23-2.12). Clinical pregnancy rates were 46.3% in the Corifollitropin alfa N02 group and 51.1% in the daily rFSH group, and ongoing pregnancy rates were 38.8% vs. 44.3% for the two groups, respectively. Safety profiles were similar: ovarian hyperstimulation syndrome occurred in 3.8% vs. 2.5% of subjects, and treatment-related adverse events occurred in 15.2% vs. 11.0% of subjects. Pooled data from Phase 2 and 3 trials reported neonatal outcomes at 12 months, with birth defect rates of 7.6% vs 12.0%. Anti-drug antibodies were detected in 3.0% of Corifollitropin alfa N02 recipients without clinical impact. Conclusions A single dose of Corifollitropin alfa N02 was non-inferior to daily rFSH in oocyte yield, with similar safety, offering a simplified ovarian stimulation alternative for Chinese women with normal ovarian reserve.