A single dose of corifollitropin alfa is equipotent to a daily dose of 300 IU recombinant FSH regardless of ovarian reserve

Abstract

Research question: What dose of daily recombinant FSH (recFSH) provides a similar ovarian response as a single dose of corifollitropin alfa (CFA) overall and in women with different ovarian reserves?

Design: This retrospective analysis of three randomized trials included 1715 patients who received a single injection of CFA and 1577 patients who were treated with daily follitropin beta with a fixed starting dose for the first week of stimulation. Data were adjusted for antral follicle count (AFC), age, body weight, and interaction between AFC and age. The dose of follitropin beta corresponding to CFA was estimated by including log(dose) as a covariate in the model.

Results: There were similar associations between AFC and the number of oocytes, and between age and the number of oocytes following CFA and daily recFSH treatment. A clear increase in the number of oocytes was observed with increasing daily doses of recFSH in normal and high responders, but not in low responders. CFA led to a greater ovarian response compared with daily 150 IU or 200 IU recFSH in normal and high responders. The number of oocytes in patients who received 100 μg and 150 μg CFA was similar to the number of oocytes in patients who received daily 300 IU recFSH in all three subsets of predicted responders. The analysis estimated that 150 μg CFA is equipotent to daily 300 IU recFSH (95% CI 251-359 IU), and 100 μg CFA is equipotent to daily 297 IU recFSH (95% CI 217-405 IU).

Conclusions: Regardless of ovarian reserve, a single dose of CFA provides a similar ovarian response as daily 300 IU recFSH in patients undergoing IVF/intracytoplasmic sperm injection.

Keywords: Corifollitropin alfa; Dose equivalence; Follitropin beta; IVF/ICSI; Ovarian stimulation.