Cost-effectiveness analysis of the use of comprehensive molecular profiling before initiating monoclonal antibody therapy against metastatic colorectal cancer in Japan

Using Genomic Heterogeneity to Inform Therapeutic Decisions for Metastatic Colorectal Cancer: An Application of the Value of Heterogeneity Framework

BACKGROUND AND OBJECTIVE

Mutations in KRAS and NRAS are predictive of poor response to cetuximab and panitumumab, two anti-epidermal growth factor receptor (EGFR) monoclonal antibodies used in metastatic colorectal cancer (mCRC). Our objective was to explore the value of using KRAS and NRAS mutation status to inform third-line anti-EGFR therapy for mCRC using the value of heterogeneity (VOH) framework.

METHODS

We used administrative data to identify mCRC patients who were potentially eligible for third-line therapy in 2006-2019 in British Columbia (BC), Canada. We compared three alternative stratification policies in place during the study period: the unstratified policy where anti-EGFR therapy was not offered (2006-2009), stratification by KRAS mutation (2009-2016), and stratification by KRAS+NRAS mutation (2016-2019). We used inverse-probability-of-treatment weighting to balance covariates across the three groups. Cost and survival time were calculated using a 3-year time horizon and adjusted for censoring, with bootstrapping to characterize uncertainty. Mean net monetary benefit (NMB) was calculated at a range of threshold values. The VOH of using KRAS and NRAS mutation status to inform treatment selection was calculated as the change in NMB with increasing stratification, under current (static VOH) or perfect (dynamic VOH) information.

RESULTS

We included 2664 patients in the analysis. At a willingness-to-pay of CA$100,000/ life-year gained (LYG), stratification on KRAS mutation status provided a static VOH of CA$1565 per patient; further stratification on KRAS+NRAS provided additional static VOH of CA$594. The static VOH exceeded the marginal cost of genomic testing under both policies.

CONCLUSIONS

Stratification of anti-EGFR therapy by KRAS and NRAS mutation status can provide additional value at a threshold of CA$100,000/LYG. There is diminishing marginal value and increasing marginal costs as the policy becomes more stratified. The VOH framework can illustrate the value of subgroup-specific decisions in a comprehensive way, to better inform targeted treatment policies.

How are we evaluating the cost-effectiveness of companion biomarkers for targeted cancer therapies? A systematic review

Background

Despite the increasing economic assessment of biomarker-guided therapies, no clear agreement exists whether existing methods are sufficient or whether different methods might produce different cost-effectiveness results. This study aims to examine current practices of modeling companion biomarkers when assessing the cost-effectiveness of targeted cancer therapies. It investigates the current methods in modeling the characteristics of companion diagnostics based on existing economic evaluations of biomarker-guided therapies in cancer.

Methods

A literature search was performed using Medline, Embase, EconLit, Cochrane library for economic evaluations of biomarker-guided therapies with companion diagnostics in cancer. Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. Studies were selected using pre-specified eligibility criteria based on the PICO framework. To make the included studies more comparable, we qualitatively synthesized the data under nine domains of methods where consensus was deemed lacking.

Results

Only four of the twenty-two studies included in this review were found to be of good quality with respect to incorporating the characteristics of companion biomarkers in economic evaluations. However, many evaluations focused on a pre-selected patient group rather than including all patients regardless of their biomarker status. Companion biomarker characteristics captured in evaluations were often limited to the cost or the accuracy of the test. Often, only the costs of biomarker testing were modelled. Clinical outcomes and health state utilities were often not included due to the limited data generated by clinical trials. Methods of economic evaluation were not applied consistently in assessments of companion cancer biomarkers for targeted therapies. It was also shown that conflicting cost-effectiveness results were likely depending on what comparator arm was chosen and what comparison structure was designed in the model.

Conclusion

We found no consistent approach applied in assessing the value of companion biomarker tests and including the characteristics of biomarkers in an economic evaluation of targeted oncology therapies. Currently, many economic evaluations fail to capture the full value of companion biomarkers beyond sensitivity/specificity and cost related to biomarker testing.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08725-4.

Health Economic Models for Metastatic Colorectal Cancer: A Methodological Review

OBJECTIVE

The aim of this systematic review was to provide a comprehensive and detailed review of structural and methodological assumptions in model-based cost-effectiveness analyses of systemic metastatic colorectal cancer (mCRC) treatments, and discuss their potential impact on health economic outcome estimates.

METHODS

Five databases (EMBASE, MEDLINE, Cochrane Library, Health Technology Assessment and National Health Service Health Economic Evaluation Database) were searched on 26 August 2019 for model-based full health economic evaluations of systemic mCRC treatment using a combination of free-text terms and subject headings. Full-text publications in English were eligible for inclusion if they were published in or after the year 2000. The Consolidated Health Economic Evaluation Reporting Standards checklist was used to assess the reporting quality of included publications. Study selection, appraisal and data extraction were performed by two reviewers independently.

RESULTS

The search yielded 1418 publications, of which 54 were included, representing 51 unique studies. Most studies focused on first-line treatment (n = 29, 57%), followed by third-line treatment (n = 13, 25%). Model structures were health-state driven (n = 27, 53%), treatment driven (n = 19, 37%), or a combination (n = 5, 10%). Cohort-level state-transition modelling (STM) was the most common technique (n = 33, 65%), followed by patient-level STM and partitioned survival analysis (both n = 6, 12%). Only 15 studies (29%) reported some sort of model validation. Health economic outcomes for specific strategies differed substantially between studies. For example, survival following first-line treatment with fluorouracil, leucovorin and oxaliplatin ranged from 1.21 to 7.33 years, with treatment costs ranging from US$8125 to US$126,606.

CONCLUSIONS

Model-based cost-effectiveness analyses of systemic mCRC treatments have adopted varied modelling methods and structures, resulting in substantially different outcomes. As models generally focus on first-line treatment without consideration of downstream treatments, there is a profound source of structural uncertainty implying that the cost-effectiveness of treatments across the mCRC pathway remains uncertain.

Cost-Effectiveness of RAS Genetic Testing Strategies in Patients With Metastatic Colorectal Cancer: A Systematic Review

BACKGROUND

Monoclonal antibodies against epidermal growth factor receptor (EGFR) have proved beneficial for the treatment of metastatic colorectal cancer (mCRC), particularly when combined with predictive biomarkers of response. International guidelines recommend anti-EGFR therapy only for RAS (NRAS,KRAS) wild-type tumors because tumors with RAS mutations are unlikely to benefit.

OBJECTIVES

We aimed to review the cost-effectiveness of RAS testing in mCRC patients before anti-EGFR therapy and to assess how well economic evaluations adhere to guidelines.

METHODS

A systematic review of full economic evaluations comparing RAS testing with no testing was performed for articles published in English between 2000 and 2018. Study quality was assessed using the Quality of Health Economic Studies scale, and the British Medical Journal and the Philips checklists.

RESULTS

Six economic evaluations (2 cost-effectiveness analyses, 2 cost-utility analyses, and 2 combined cost-effectiveness and cost-utility analyses) were included. All studies were of good quality and adopted the perspective of the healthcare system/payer; accordingly, only direct medical costs were considered. Four studies presented testing strategies with a favorable incremental cost-effectiveness ratio under the National Institute for Clinical Excellence (£20 000-£30 000/QALY) and the US ($50 000-$100 000/QALY) thresholds.

CONCLUSIONS

Testing mCRC patients for RAS status and administering EGFR inhibitors only to patients with RAS wild-type tumors is a more cost-effective strategy than treating all patients without testing. The treatment of mCRC is becoming more personalized, which is essential to avoid inappropriate therapy and unnecessarily high healthcare costs. Future economic assessments should take into account other parameters that reflect the real world (eg, NRAS mutation analysis, toxicity of biological agents, genetic test sensitivity and specificity).

Do cancer biomarkers make targeted therapies cost-effective? A systematic review in metastatic colorectal cancer

BACKGROUND

Recent advances in targeted therapies have raised expectations that the clinical application of biomarkers would improve patient's health outcomes and potentially save costs. However, the cost-effectiveness of biomarkers remains unclear irrespective of the cost-effectiveness of corresponding therapies. It is thus important to determine whether biomarkers for targeted therapies provide good value for money. This study systematically reviews economic evaluations of biomarkers for targeted therapies in metastatic colorectal cancer (mCRC) and assesses the cost-effectiveness of predictive biomarkers in mCRC.

METHODS

A literature search was performed using Medline, Embase, EconLit, NHSEED. Papers published from 2000 until June 2018 were searched. All economic evaluations assessing biomarker-guided therapies with companion diagnostics in mCRC were searched. To make studies more comparable, cost-effectiveness results were synthesized as per biomarker tests and corresponding therapies. Methodological quality was assessed using the Quality of Health Economic Studies (QHES) instrument.

RESULTS

Forty-six studies were included in this review. Of these, 17 studies evaluated the intrinsic value of cancer biomarkers, whereas the remaining studies focused on assessing the cost-effectiveness of corresponding drugs. Most studies indicated favourable cost-effectiveness of biomarkers for targeted therapies in mCRC. Some studies reported that biomarkers were cost-effective, while their corresponding therapies were not cost-effective. A considerable number of economic evaluations were conducted in pre-defined genetic populations and thus, often failed to fully capture the biomarker's clinical and economic values. The average QHES score was 73.6.

CONCLUSION

Cancer biomarkers for targeted therapies in mCRC were mostly found to be cost-effective; otherwise, they at least improved the cost-effectiveness of targeted therapies by saving some costs. However, this did not necessarily make their corresponding therapies cost-effective. While companion biomarkers reduced therapy costs, the savings were not sufficient to make the corresponding agents cost-effective. Evaluation of biomarkers was often restricted to the cost of tests and did not consider their clinical values or biomarker prevalence.

Methodological Issues in Assessing the Economic Value of Next-Generation Sequencing Tests: Many Challenges and Not Enough Solutions

BACKGROUND

Clinical use of next-generation sequencing (NGS) tests has been increasing, but few studies have examined their economic value. Several studies have noted that there are methodological challenges to conducting economic evaluations of NGS tests.

OBJECTIVE

Our objective was to examine key methodological challenges for conducting economic evaluations of NGS tests, prioritize these challenges for future research, and identify how studies have attempted solutions to address these challenges.

METHODS

We identified challenges for economic evaluations of NGS tests using prior literature and expert judgment of the co-authors. We used a modified Delphi assessment to prioritize challenges, based on importance and probability of resolution. Using a structured literature review and article extraction we then assessed whether published economic evaluations had addressed these challenges.

RESULTS

We identified 11 challenges for conducting economic evaluations of NGS tests. The experts identified three challenges as the top priorities for future research: complex model structure, timeframe, and type of analysis and comparators used. Of the 15 published studies included in our literature review, four studies described specific solutions relevant to five of the 11 identified challenges.

CONCLUSIONS

Major methodological challenges to economic evaluations of NGS tests remain to be addressed. Our results can be used to guide future research and inform decision-makers on how to prioritize research on the economic assessment of NGS tests.