P-578 A combined analysis to establish the equipotency of corifollitropin alfa in comparison to daily recombinant FSH including individual data of 3292 IVF/ICSI patients
Authors: Garcia-Velasco J  A , Fernandez-Sanchez M , Larsson P , Mannaerts B 
Published: July 2024

Study question

What daily dose of follitropin beta provides a similar ovarian response as single dose of corifollitropin alfa (CFA) in women with different ovarian reserve?

Summary answer

Regardless of ovarian reserve, a single dose of CFA provides a similar ovarian response as 300 IU/day follitropin beta in IVF/ICSI patients.

What is known already

A single dose of CFA replaces the first week of stimulation with daily recFSH and provides robust ovarian stimulation due to its unique pharmacokinetic profile. Previous controlled trials in IVF/ICSI patients have demonstrated that CFA yields more oocytes than daily recFSH. In women up to 36 years, on average +2.5 oocytes were obtained in comparison to daily 150 IU recFSH and +1.2 oocytes in comparison to daily 200 IU recFSH, whereas this difference was only +0.5 oocytes in comparison to daily 300 IU recFSH in women aging 35 to 42 years.

Study design, size, duration

This was a retrospective analysis using individual patient data from 3 large, randomized trials, including 1715 IVF patients receiving a single injection of 100 or 150 mg CFA, followed by daily follitropin beta injections from day 8, and 1577 IVF patients treated with daily follitropin beta with a fixed starting dose of 150 IU, 200 IU or 300 IU for the first week of stimulation.

Participants/materials, setting, methods

The mean number of oocytes retrieved were estimated for each treatment and predicted response group (Low: AFC≤7 (n = 595), Normal: 8≥AFC≤14 (n = 1899), High: AFC≥15 (n = 808)). Pooling of the three trials was enabled by adjusting for AFC, age, body weight, and the interaction between AFC and age, all as continuous covariates. The dose of follitropin beta corresponding to CFA was estimated by including log(dose) as a covariate in the model.

Main results and the role of chance

There were similar positive associations between AFC and oocytes and negative associations between age and oocytes following CFA and daily recFSH treatment. There was no clear association between body weight and oocytes following either treatment. A clear increase in number of oocytes was observed with increasing daily doses of recFSH in predicted normal and predicted high responders, but not in predicted low responders. Accordingly, regardless the dose, CFA was providing an ovarian response higher than daily 150 IU or 200 IU recFSH in normal and high responders. The number of oocytes following 100 mg and 150 mg CFA was comparable in all three subsets of predicted responders and similar to the number of oocytes following daily treatment with 300 IU recFSH. The analysis estimated a single dose of 150 mg CFA to be equipotent to daily 300 IU recFSH (95% CI 251-359 IU) and a single dose of 100 mg CFA to be equipotent to 297 IU recFSH daily (95% CI 217-405 IU).

Limitations, reasons for caution

This retrospective analysis excludes patients with an irregular cycle, suffering from PCOS or having an AFC &gt;20. Thus, the data cannot be extrapolated to these patients

Wider implications of the findings

Daily doses of recFSH provide dose-related increases of ovarian response in normal and high responders. With CFA treatment, the potential of a single IVF cycle is maximised with an ovarian response comparable to daily 300 IU recFSH, which can be safely managed by GnRH agonist triggering and a freeze-all strategy.

Trial registration number

NCT00696800, NCT00702845, NCT01144416