Background: The first histology-independent marketing authorisation in Europe was granted in 2019. This was the first time that a cancer treatment was approved based on a common biomarker rather than the location in the body at which the tumour originated. This research aims to explore the implications for National Institute for Health and Care Excellence appraisals.
Methods: Targeted reviews were undertaken to determine the type of evidence that is likely to be available at the point of marketing authorisation and the analyses required to support National Institute for Health and Care Excellence appraisals. Several challenges were identified concerning the design and conduct of trials for histology-independent products, the greater levels of heterogeneity within the licensed population and the use of surrogate end points. We identified approaches to address these challenges by reviewing key statistical literature that focuses on the design and analysis of histology-independent trials and by undertaking a systematic review to evaluate the use of response end points as surrogate outcomes for survival end points. We developed a decision framework to help to inform approval and research policies for histology-independent products. The framework explored the uncertainties and risks associated with different approval policies, including the role of further data collection, pricing schemes and stratified decision-making.
Results: We found that the potential for heterogeneity in treatment effects, across tumour types or other characteristics, is likely to be a central issue for National Institute for Health and Care Excellence appraisals. Bayesian hierarchical methods may serve as a useful vehicle to assess the level of heterogeneity across tumours and to estimate the pooled treatment effects for each tumour, which can inform whether or not the assumption of homogeneity is reasonable. Our review suggests that response end points may not be reliable surrogates for survival end points. However, a surrogate-based modelling approach, which captures all relevant uncertainty, may be preferable to the use of immature survival data. Several additional sources of heterogeneity were identified as presenting potential challenges to National Institute for Health and Care Excellence appraisal, including the cost of testing, baseline risk, quality of life and routine management costs. We concluded that a range of alternative approaches will be required to address different sources of heterogeneity to support National Institute for Health and Care Excellence appraisals. An exemplar case study was developed to illustrate the nature of the assessments that may be required.
Conclusions: Adequately designed and analysed basket studies that assess the homogeneity of outcomes and allow borrowing of information across baskets, where appropriate, are recommended. Where there is evidence of heterogeneity in treatment effects and estimates of cost-effectiveness, consideration should be given to optimised recommendations. Routine presentation of the scale of the consequences of heterogeneity and decision uncertainty may provide an important additional approach to the assessments specified in the current National Institute for Health and Care Excellence methods guide.
Further research: Further exploration of Bayesian hierarchical methods could help to inform decision-makers on whether or not there is sufficient evidence of homogeneity to support pooled analyses. Further research is also required to determine the appropriate basis for apportioning genomic testing costs where there are multiple targets and to address the challenges of uncontrolled Phase II studies, including the role and use of surrogate end points.
Funding: This project was funded by the National Institute for Health Research (NIHR) Evidence Synthesis programme and will be published in full in Health Technology Assessment; Vol. 25, No. 76. See the NIHR Journals Library website for further project information.
Keywords: BAYES THEOREM; BIOMARKERS; COST–BENEFIT ANALYSIS; DATA COLLECTION; GENETIC TESTING; NEOPLASMS; POLICY; UNCERTAINTY.
In May 2017, the US Food and Drug Administration granted the first approval for a cancer treatment based on a common biomarker rather than the location in the body at which the tumour originated (the tumour site); that is, a site-agnostic or ‘histology-independent’ indication was granted. Research from the National Institute for Health and Care Excellence suggests that there are approximately 20 technologies currently in development for histology-independent indications. The first marketing authorisation was granted in Europe in 2019. Histology-independent treatments have the potential to have important effects in patient populations for whom there are currently limited or no available treatment options. However, it is also important to ensure that the use of these treatments in the NHS is supported by systematic and robust assessments of clinical evidence (i.e. how well the medicine or treatment works) and economic evidence (i.e. the medicine’s value for money). These assessments are undertaken by the National Institute for Health and Care Excellence, usually for treatments targeting specific tumours sites. However, a histology-independent marketing authorisation would probably include many tumour sites and it is not possible for the National Institute for Health and Care Excellence to conduct a separate assessment for each tumour site for which the treatment could be beneficial. As a result, the National Institute for Health and Care Excellence needs to consider how these products can be appropriately assessed without creating unnecessary delays in patient access. This research explores the extent to which the National Institute for Health and Care Excellence’s existing approaches for assessing clinical and economic value can be applied to histology-independent indications, and any changes that might be required. We explore the nature and amount of evidence that is typically available at the point of initial marketing authorisation and develop recommendations to establish the evidence and analyses required to help inform the National Institute for Health and Care Excellence’s decisions. We use case studies to highlight possible challenges and to explore ways that these challenges might be addressed. This research will help to inform future National Institute for Health and Care Excellence policy on how to appraise cancer drugs with histology-independent indications. It will also inform the development of guidance for those developing these treatments to help their understanding of the clinical effectiveness and cost-effectiveness assessments that will be required to inform the National Institute for Health and Care Excellence’s appraisals.