All Times EDT
Keywords: biosimilars, equivalence margin, binary endpoint, outcome response rate
Conducting a global program in biosimilar development raises many scientific challenges. One key component in the biosimilar study design is to determine the choice of primary endpoint defined in absolute versus relative difference scales, especially for binary endpoint in immuno-oncology studies.
In addition, the choice of an equivalence margin (EQM) defined in an absolute metric (e.g., rate difference (RD)) or a relative metric (e.g., rate ratio (RR)) is controversial and no consensus has been reached. There is a common misunderstanding of the equivalence of EQMs in RD vs. RR in the design of biosimilar studies. The objective of this presentation is to 1) demonstrate the equivalence based on the conversion between EQMs in RD vs RR does not hold as the true response rate changes; 2) investigate the variability of these two types of endpoints when outcome response rate changes; 3) explore the sensitivity of study power on outcome response rate using the two different EQM metrics.
Simulations results and conclusions will be provided with graphic illustrations.