The Need for Combined Assessment of Multiple Outcomes in Noninferiority Trials in Oncology

Noninferiority trials in oncology assess novel therapies with the potential for slightly worse recurrence or death outcomes (ie, the margin of noninferiority) than standard therapies. This poses a dilemma because, in the absence of potential health outcome advantages, these trials may not provide the treatment equipoise required for an ethical study. Any new treatment with the potential for slightly worse recurrence or death outcomes should have countervailing health outcome advantages, but these are rarely taken into account in the design of noninferiority trials. This article presents the argument that not only the potentially worse health outcomes but also the potential benefits of the novel therapy should be considered when designing, analyzing, and reporting noninferiority trials. Some approaches to study design and analysis that consider both primary and secondary end points are discussed, and reporting the joint distributions of end points for the novel and standard treatments is recommended.