RESEARCH QUESTIONAre QL1012 and Gonal-f® equivalent in women undergoing ovarian stimulation for assisted reproductive technology (ART)?DESIGNThis multicentre, randomized, assessor-blinded, phase-three trial was conducted at 13 centres in China. Eligible patients were infertile women; age 20-39 years; body mass index 18-30 kg/m2; regular menstrual cycles; and indication for ART. After successful pituitary downregulation, patients were randomly assigned (1:1) to receive QL1012 or Gonal-f®, stratified by age (initial dose of 75-150 IU for women younger than 30 years, 150-225 IU for women aged 30-34 years and 225-300 IU for women aged ≥35 years, subcutaneously, once daily). The primary end point was the number of oocytes retrieved.RESULTSBetween October 2018, and June 2019, 341 patients were included in the per-protocol set. The mean numbers of oocytes retrieved were 14.7 ± 7.0 in the QL1012 group (n = 169) and 13.4 ± 6.1 in the Gonal-f® group (n = 172). Adjusted by analysis of covariance model, the least-squares mean difference was 1.3 oocytes (95% CI -0.1 to 2.7; P = 0.0650), within the pre-defined equivalence margins of ±3.0. Similar results were observed in the full analysis set. Additionally, no statistical differences were found in secondary end points except oestradiol concentration (median 3948.0 pg/ml versus 3545.3 pg/ml; P = 0.0015). Ovarian hyperstimulation syndrome (12.4% versus 13.1 %) and other adverse events were similar between the two groups.CONCLUSIONSTherapeutic equivalence and similar safety profiles were demonstrated between QL1012 and Gonal-f® in women undergoing ovarian stimulation for ART.