A large Chinese study looked at how safe and effective ganirelix, a hormone‑blocking peptide, is when used in IVF cycles. Most side effects were mild, serious problems were rare and not linked to the drug, and about one‑third of women ended up with a live birth. No new safety warnings showed up.

This study aimed to evaluate the safety and effectiveness of ganirelix acetate for Chinese women undergoing ovarian stimulation (OS) in real-world clinical practice. This multicenter (16), prospective, single-arm, observational, post-authorization safety study included 1025 Chinese women receiving at least one dose of ganirelix during OS. Safety endpoints were collected until 5 weeks after embryo transfer. The investigator assessed the causality and seriousness of an adverse event (AE). Effectiveness and neonatal outcomes were collected from medical records and phone call follow-ups. The study had a probability of >95% to observe an AE occurring at 0.3% with a sample size of 1000. The occurrence of overall AEs, drug-related AEs, and serious AEs (SAEs) was 12.1% (124/1025), 1.3% (13/1025), and 2.4% (25/1025), respectively. None of the SAEs were drug related, according to the investigator. Two (0.2%) patients discontinued treatment due to an AE. The most reported AE was ovarian hyperstimulation syndrome (4.8%, 49/1025), among which 21 cases were reported as SAE. The proportion of patients with a premature luteinizing hormone (LH) rise >10 IU/L) was 2.5% (26/1025), and one patient had a premature ovulation. The live birth rate was 34.9% (358/1025) per start cycle with a cumulative live birth rate of 42.1% (432/1025). Neonatal malformations occurred in 1.3% (7/523) of the neonates. This study indicates that the safety profile and effectiveness of ganirelix were clinically acceptable, and no new safety signals emerged in real-world clinical practice for Chinese women with OS. The study was registered on Chinadrugtrial.org (identifier: CTR20150284) (http://www.chinadrugtrials.org.cn) and ENCePP.eu (identifier: EUPAS8737) (https://catalogues.ema.europa.eu).