Biosimilars versus the originator of follitropin alfa: Randomized controlled trials are still the best way to evaluate their comparative effectiveness in assisted reproduction.

Biosimilars of follitropin alfa have been introduced in many countries as more affordable alternatives to the reference product for patients undergoing ovarian stimulation for assisted reproductive technology cycles. A recent meta-analysis, by reviewing available evidence originating from randomised controlled trials, has shown that based on the best available evidence, biosimilars of follitropin alfa are associated with lower live birth, ongoing and clinical pregnancy rates compared to the reference product. A subsequently published opinion paper challenges the methodology and results of this meta-analysis and suggests that these data should be ignored. In the present paper, it is clearly demonstrated why this criticism is largely unfounded and in stark contradiction with basic principles of evidence-based medicine. Furthermore, it is presented why the results of this meta-analysis provide the best available evidence to date and therefore the base that should inform clinical practice and, importantly, stimulate further research.