Abstract
STUDY QUESTION: Is ovarian stimulation with follitropin delta in its individualised fixed-dose regimen at least as efficacious as follitropin alfa in a conventional dosing regimen in Asian population? SUMMARY ANSWER: Ovarian stimulation with individualised follitropin delta dosing resulted in a non-inferior ongoing pregnancy rate, a significantly higher live birth rate and a significantly lower incidence of early ovarian hyperstimulation syndrome (OHSS) and/or preventive interventions compared to conventional follitropin alfa dosing. WHAT IS KNOWN ALREADY: Previous randomised controlled trials conducted in Japan as well as in Europe, North- and South America have demonstrated that ovarian stimulation with the individualised follitropin delta dosing regimen based on serum anti-Müllerian hormone (AMH) level and body weight modulated the ovarian response and reduced the risk of OHSS without compromising pregnancy and live birth rates. STUDY DESIGN, SIZE, DURATION: Randomised, controlled, multi-centre, assessor-blind trial conducted in 1009 Asian patients from mainland China, South Korea, Vietnam and Taiwan, undergoing their first IVF/ICSI cycle. Randomisation was stratified by age (<35, 35-37, 38-40 years). The primary endpoint was ongoing pregnancy rate assessed 10-11 weeks after embryo transfer in the fresh cycle (non-inferiority limit -10.0%; analysis adjusted for age stratum). PARTICIPANTS/MATERIALS, SETTING, METHODS: The follitropin delta treatment consisted of a fixed daily dose individualised according to each patient's initial AMH level and body weight (AMH <15 pmol/l: 12 μg; AMH ≥15 pmol/l: 0.19 to 0.10 μg/kg; min-max 6-12 μg). The follitropin alfa dose was 150 IU/day for the first 5 days with subsequent potential dose adjustments according to individual response. A GnRH antagonist protocol was applied. OHSS was classified based on Golan's system. Women with an ongoing pregnancy were followed until live birth and 4 weeks after. MAIN RESULTS AND THE ROLE OF CHANCE: The number of oocytes retrieved was significantly (P < 0.001) lower with individualised follitropin delta versus conventional follitropin alfa (10.0 ± 6.1 versus 12.4 ± 7.3). Nevertheless, compared to the conventional dosing approach, the individualised follitropin delta dosing regimen resulted in on average 2 more oocytes (9.6 ± 5.3 versus 7.6 ± 3.5) in potential low responders as indicated by AMH <15 pmol/l, and on average 3 fewer oocytes (10.1 ± 6.3 versus 13.8 ± 7.5) in potential high responders as indicated by AMH ≥15 pmol/l. Among women with AMH ≥15 pmol/l, excessive response occurred less frequently with individualised follitropin delta than with follitropin alfa (≥15 oocytes: 20.2% versus 39.1%; ≥20 oocytes: 6.7% versus 18.5%; both P < 0.001). The incidence of early OHSS and/or preventive interventions for early OHSS was significantly (P = 0.004) reduced from 9.6% with follitropin alfa to 5.0% with individualised follitropin delta. The total gonadotropin use was significantly (P < 0.001) reduced from an average of 109.9 ± 32.9 μg (1498 ± 448 IU) follitropin alfa to 77.5 ± 24.4 μg follitropin delta. Non-inferiority of follitropin delta in its individualised dosing regimen to conventional follitropin alfa was established with respect to the primary endpoint of ongoing pregnancy rate which was 31.3% with follitropin delta compared to 25.7% with follitropin alfa (estimated mean difference 5.4% [95% CI: -0.2%; 11.0%]). The live birth rate was significantly higher at 31.3% with individualised follitropin delta compared to 24.7% with follitropin alfa (estimated mean difference 6.4% [95% CI: 0.9%; 11.9%]; P = 0.023). The live birth rate for each stratum were as follows for follitropin delta and follitropin alfa, respectively; <35 years: 31.0% versus 25.0%, 35-37 years: 35.3% versus 26.7%, 38-40 years: 20.0% versus 14.3%. LIMITATIONS, REASONS FOR CAUTION: The trial only covered the clinical outcome of one treatment cycle with fresh cleavage-stage embryo transfers. WIDER IMPLICATIONS OF THE FINDINGS: The present trial shows that in addition to reducing the early OHSS risk, follitropin delta in its individualised fixed-dose regimen has the potential to improve the success rate in fresh cycles across all ages and with a lower gonadotropin consumption compared to conventional follitropin alfa dosing. STUDY FUNDING/COMPETING INTEREST(S): This study was funded by Ferring Pharmaceuticals. J.Q., Y.Z., X.L., T.H., H.-Y.H. and S.-H.K. have received institutional (not personal) clinical trial fees from Ferring Pharmaceuticals. M.G., B.M. and J.-C.A. are employees of Ferring Pharmaceuticals. J.-C.A. has pending and issued patent applications in the WO 2013/020996 and WO 2019/043143 patent families that comprise allowed and granted patent rights related to follitropin delta. TRIAL REGISTRATION NUMBER: NCT03296527 (clinicaltrials.gov). TRIAL REGISTRATION DATE: 28 September 2017. DATE OF FIRST PATIENT’S ENROLMENT: 1 December 2017.