Corifollitropin alfa vs recombinant FSH for controlled ovarian stimulation in women aged 35-42 years with a body weight ≥50 kg: a randomized controlled trial

STUDY QUESTION: Is corifollitropin alfa 150 mu g equivalent to follitropin beta 300 IU/day for controlled ovarian hyperstimulation (COS) in older women weighing >= 50 kg undergoing IVF and/or ICSI in Vietnam? SUMMARY ANSWER: Corifollitropin alfa 150 mu g was equivalent to follitropin beta 300 IU/day with respect to the number of oocytes retrieved, the ongoing, cumulative and live birth rates and obstetric outcomes. WHAT IS KNOWN ALREADY: Corifollitropin alfa is a recombinant FSH (rFSH) preparation with slow absorption and a long half-life allowing administration of a single dose for COS lasting 7 days. Several randomized, controlled clinical trials have reported that COS with corifollitropin alfa is associated with similar outcomes compared with COS using daily rFSH. However, limited data are available in Asian patients. STUDY DESIGN, SIZE, DURATION: This randomized controlled trial was conducted at a single large IVF centre in Vietnam from June 2015 to August 2016. A total of 400 patients were included, 200 in each treatment group. The primary outcome measure was the number of oocytes retrieved. Patients were followed for 1 year after randomization. PARTICIPANTS /MATERIALS, SETTING, METHODS: Participants aged 35-42 years with a body weight >= 50 kg who were undergoing an IVF cycle were randomized to undergo COS with a single dose of corifollitropin alfa 150 mu g on Day 2 or 3 of the menstrual cycle, or follitropin beta 300 IU/day for 7 days starting on Day 2 or 3 of the menstrual cycle. All underwent ICSI according to standard institutional protocols. A beta hCG test was performed 17 days after ovum pick-up, and positive tests were confirmed on vaginal and/or abdominal ultrasound at 5-6 weeks after embryo transfer (clinical pregnancy) and at >= 10 weeks (ongoing pregnancy). Rates of ovarian hyperstimulation syndrome, and maternal and foetal outcomes after one cycle of ICSI were monitored over 12 months. MAIN RESULTS AND THE ROLE OF CHANCE: Patients in the corifollitropin alfa and follitropin beta groups were well matched at baseline (mean age 37.5 1.9 vs 37.7 2.0 years, mean body weight 53.7 5.4 vs 52.5 4.8 kg). There was no significant difference between the corifollitropin alfa and follitropin beta groups in the number of oocytes retrieved (11.4 5.9 vs 10.8 5.8; P = 0.338). The ongoing pregnancy rate (31.5 vs 32.0%; P = 0.99) and live birth rate (30.5 vs 32.0%; P = 0.83) (both per initiated cycle at 12 months after randomization) were also similar in the two treatment groups. Complication rates were low and similar in the corifollitropin alfa and follitropin beta groups, and there were no significant between-group differences in obstetric outcomes. LIMITATIONS, REASONS FOR CAUTION: This study had an open-label design, and therefore, the potential for bias cannot be excluded. The findings are only applicable to patient populations with similar characteristics to those enroled in the study. WIDER IMPLICATIONS OF THE FINDINGS: This study adds to the body of evidence supporting the equivalence of corifollitropin alfa and follitropin beta for COS in a variety of patients undergoing IVF and/or ICSI. The ability to provide COS with corifollitropin alfa has the potential to reduce the burden of treatment for patients.