Bayesian Hierarchical Models of Basket Trials in the Context of Economic Evaluation

Key Messages

What Was the Problem or Question?

• With the availability of advanced genomic profiling methods, basket trials are more commonly used for the clinical assessment of treatments targeting multiple cancer types with a common biomarker. Basket trials study a primary intervention across a range of different patient subgroups (e.g., with specific cancer types) that share similar features (e.g., mutations or biomarkers), in which the effect of the primary intervention may be expected to differ. Heterogeneity among cancer types, limited sample sizes, a lack of comparators, and the use of surrogate end points pose challenges when considering the application to economic evaluations. Bayesian hierarchical models (BHMs) are well suited to account for the heterogeneity among cancer types while borrowing information across cancer types in basket trials. There is a need for clearer guidance about how these methods can be used in health technology assessment (HTA).

What Did We Do?

• To better understand the role of BHMs in economic evaluations, an overview of basket trials and the current understanding of their use in economic evaluations was conducted, an illustration of how BHMs can inform economic evaluations was provided with a detailed example, and considerations for interpretating and appraising this information were listed.

What Did We Find?

• BHMs offer an approach to use information from basket trials to inform economic evaluations; however, there are limitations to be aware of when using this information in economic evaluations and also when interpreting the results of the economic information. This document describes these limitations, and contains an appraisal list that was developed to highlight the implications. These are aspects that CADTH considers when assessing analyses based on BHMs. The field of BHMs is evolving, and advice in this document will need to be revisited as methods develop.

What Does This Mean?

• As CADTH anticipates the increased need for appraisal of tumour-agnostic therapies, this document provides clarity around an important and useful set of methods for their evaluation, while also highlighting necessary areas for further research.