Towards an economic evidence base for pharmacogenetics: consideration of outcomes is key

Using Cost-Effectiveness Analysis to Quantify the Value of Genomic-Based Diagnostic Tests: Recommendations for Practice and Research

AIMS

New sequencing technologies allow increased opportunities to use genomic-based diagnostic tests (genomic tests) in routine clinical practice, which will impact healthcare budgets and patients' outcomes. This article aims to generate a list of recommendations on how the principles and methods of cost-effectiveness analysis (CEA) can be used to quantify the costs and benefits of genomic tests.

METHODS

A systematic literature search identified publications describing the use of CEA to evaluate genomic tests. Data were extracted as key concepts to produce a thematic list of previously described challenges and solutions to using CEA to evaluate genomic tests. Defining features of evaluating genomic tests were categorized into a list of key recommendations for applying methods in practice and for research needs.

RESULTS

Features producing challenges in the implementation of CEA to evaluate genomic tests were as follows: the ability of the tests to diagnose multiple disorders; potential consequences for future generations suggesting an infinite time horizon; and the potential need to consider nonhealth benefits.

CONCLUSIONS

CEA was identified as an appropriate evaluative framework for genomic tests, although standard methods may need modification and important method research questions remain. Key recommendations suggest a need for research to reflect: sharing genomic information across generations; genomic tests for multiple disorders; and health and nonhealth benefits.

Issues surrounding the health economic evaluation of genomic technologies

AIM

Genomic interventions could enable improved disease stratification and individually tailored therapies. However, they have had a limited impact on clinical practice to date due to a lack of evidence, particularly economic evidence. This is partly because health economists are yet to reach consensus on whether existing methods are sufficient to evaluate genomic technologies. As different approaches may produce conflicting adoption decisions, clarification is urgently required. This article summarizes the methodological issues associated with conducting economic evaluations of genomic interventions.

MATERIALS & METHODS

A structured literature review was conducted to identify references that considered the methodological challenges faced when conducting economic evaluations of genomic interventions.

RESULTS

Methodological challenges related to the analytical approach included the choice of comparator, perspective and timeframe. Challenges in costing centered around the need to collect a broad range of costs, frequently, in a data-limited environment. Measuring outcomes is problematic as standard measures have limited applicability, however, alternative metrics (e.g., personal utility) are underdeveloped and alternative approaches (e.g., cost-benefit analysis) underused. Effectiveness data quality is weak and challenging to incorporate into standard economic analyses, while little is known about patient and clinician behavior in this context. Comprehensive value of information analyses are likely to be helpful.

CONCLUSION

Economic evaluations of genomic technologies present a particular challenge for health economists. New methods may be required to resolve these issues, but the evidence to justify alternative approaches is yet to be produced. This should be the focus of future work in this field.

Are health technology assessments of pharmacogenetic tests feasible? A case study of CYP2D6 testing in the treatment of breast cancer with tamoxifen

This paper reports the process and experience of the design and conduct of a UK-based health technology assessment (HTA) of CYP2D6 pharmacogenetic testing to inform the targeted use of tamoxifen for the treatment of breast cancer. Examples of particular challenges for conducting a HTA are highlighted. It is clear from the HTA process described here that a common finding of similar future HTAs will have gaps in the evidence base, particularly in relation to evidence to inform cost–effectiveness. The lack of evidence is likely to be sufficiently large to result in extreme uncertainty and possibly decisions not to recommend a pharmacogenetic test for use in clinical practice. This has clear negative implications, which may hamper moving pharmacogenetic tests from the research environment into clinical practice and requires attention from both manufacturers of pharmacogenetic tests and key decision-makers responsible for market authorization and reimbursement.

Cost-effectiveness analysis in pharmacogenomics

The existence of finite healthcare budgets drives the need to consider opportunity cost and demonstrate that pharmacogenomic interventions offer added value, in terms of the relative costs and benefits, compared with current practice. This is where the framework of cost-effectiveness analysis is useful. Existing systematic reviews of economic evaluations of genetic technologies have all highlighted the need to improve the quality of the economics evidence base. More recent cost-effectiveness analyses of pharmacogenomics are generally of higher quality. The future will see an increase in the number of published cost-effectiveness analyses. Critical appraisal of these analyses is necessary to ensure the evidence base is sufficiently robust to inform resource allocation decisions at local and national levels.

Pharmacogenetics education: 10 years of experience at Tel Aviv University

Lack of knowledge among clinicians regarding pharmacogenetics is often cited as one of the barriers delaying its clinical uptake, albeit there are many other, more crucial aspects that impede the implementation of pharmacogenetics into routine medical practice. Pharmacogenetics has been incorporated to the MD teaching curriculum at the Tel Aviv University Faculty of Medicine (Tel Aviv, Israel) since 2001 and offered as an elective class for graduate students since 2003. I share here my pharmacogenetics teaching experience over the past decade and look forward to 2020 when – hopefully – the use of pharmacogenetics tools will have become more established in routine clinical care.

Improving pharmacovigilance in Europe: TPMT genotyping and phenotyping in the UK and Spain

Thiopurine S-methyltransferase (TPMT) is the rate-limiting step in the conversion of thiopurine drugs including azathioprine (AZA) to inactive metabolites. Heritable deficiency of TPMT activity increases risk for adverse events, most notably, myelosuppression leading to leukopenia and neutropenic sepsis. The reported European Commission study was undertaken to identify current evidence for the clinical utility of testing for TPMT status and extent of uptake, by either genotyping or phenotyping, in the clinical setting. Data presented here for the UK and Spain indicate that there has been a considerable increase in the uptake of TPMT testing in recent years. There are some data that support routine TPMT testing before AZA prescribing for reducing AZA-related adverse events. Key data include evidence in favor of TPMT testing in addition to the current practice of routine monitoring for reducing the number of AZA-related episodes of myelosuppression, averting deaths from neutropenic sepsis and improving health-related quality of life. Further data are needed for determining the cost-effectiveness of routine TPMT testing.

Removing barriers to a clinical pharmacogenetics service

Pharmacogenetics has been proposed as a new discipline to facilitate safer and more effective prescribing by predicting individuals who will have a therapeutic response or develop side effects. Implementation of pharmacogenetic testing into mainstream clinical practice has been slow. However, recent studies provide robust evidence that pharmacogenetics can make real differences to reduce adverse reactions to certain medications. It is therefore important to consider what factors influence the introduction of pharmacogenetics into clinical practice and what requirements must be met to ensure an effective, safe, efficient and equitable pharmacogenetics service.

Drug safety assurance through clinical genotyping: near-term considerations for a system-wide implementation of personalized medicine

The rationale and overall system-wide behavior of a clinical genotyping information system (both DNA analysis and data management) requires a near-term, scalable approach, which is emerging in the focused implementation of pharmacogenomics and drug safety assurance. The challenges to implementing a successful clinical genotyping system are described, as are how the benefits of a focused, near-term system for drug safety assessment and assurance overcome the logistical and operational challenges that perpetually hinder the development of a societal-scale clinical genotyping system. This rationale is based on the premise that a focused application domain for clinical genotyping, specifically drug safety assurance, provides a transition paradigm for both professionals and consumers of healthcare, thereby facilitating the movement of genotyping from bench to bedside and paving the way for the adoption of prognostic and diagnostic applications in clinical genomics.