Open AccessAssessing Clinical Equivalence in Oncology Biosimilar Trials With Time-to-Event Outcomes
Author(s) -
Hajime Uno,
Deborah Schrag,
Dae Hyun Kim,
Dejun Tang,
Lu Tian,
Hope S. Rugo,
LeeJen Wei
Publication year - 2019
Publication title -
jnci cancer spectrum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.345
H-Index - 10
ISSN - 2515-5091
DOI - 10.1093/jncics/pkz058
Subject(s) - biosimilar , medicine , clinical endpoint , equivalence (formal languages) , hazard ratio , clinical trial , oncology , endpoint determination , survival analysis , confidence interval , mathematics , discrete mathematics
A typical biosimilar study in oncology uses the overall response evaluated at a specific time point as the primary endpoint, which is generally acceptable regulatorily, to assess clinical equivalence between a biosimilar and its reference product. The standard primary endpoint for evaluating an anticancer therapy, progression-free or overall survival would be a secondary endpoint in a biosimilar trial. With a conventional analytic procedure via, for example, hazard ratio to quantify the group difference, it is difficult and challenging to assess clinical equivalence with respect to progression-free or overall survival because the study generally has a limited number of clinical events observed in the study. In this article, we show that an alternative procedure based on the restricted mean survival time, which has been discussed extensively for design and analysis of a general equivalence study, is readily applicable to a biosimilar trial. Unlike the hazard ratio, this procedure provides a clinically interpretable estimate for assessing equivalence. Using the restricted mean survival time as a summary measure of the survival curve will enhance better treatment decision making in adopting a biosimilar product over the reference product.