Cost-effectiveness of cetuximab in combination with irinotecan compared with current care in metastatic colorectal cancer after failure on irinotecan--a Belgian analysis

Summarising salient information on historical controls: A structured assessment of validity and comparability across studies

BACKGROUND

While placebo-controlled randomised controlled trials remain the standard way to evaluate drugs for efficacy, historical data are used extensively across the development cycle. This ranges from supplementing contemporary data to increase the power of trials to cross-trial comparisons in estimating comparative efficacy. In many cases, these approaches are performed without in-depth review of the context of data, which may lead to bias and incorrect conclusions.

METHODS

We discuss the original 'Pocock' criteria for the use of historical data and how the use of historical data has evolved over time. Based on these factors and personal experience, we created a series of questions that may be asked of historical data, prior to their use. Based on the answers to these questions, various statistical approaches are recommended. The strategy is illustrated with a case study in colorectal cancer.

RESULTS

A number of areas need to be considered with historical data, which we split into three categories: outcome measurement, study/patient characteristics (including setting and inclusion/exclusion criteria), and disease process/intervention effects. Each of these areas may introduce issues if not appropriately handled, while some may preclude the use of historical data entirely. We present a tool (in the form of a table) for highlighting any such issues. Application of the tool to a colorectal cancer data set demonstrates under what conditions historical data could be used and what the limitations of such an analysis would be.

CONCLUSION

Historical data can be a powerful tool to augment or compare with contemporary trial data, though caution is required. We present some of the issues that may be considered when involving historical data and what (if any) statistical approaches may account for differences between studies. We recommend that, where historical data are to be used in analyses, potential differences between studies are addressed explicitly.

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.

Economic Evaluations of Pharmaceuticals Granted a Marketing Authorisation Without the Results of Randomised Trials: A Systematic Review and Taxonomy

BACKGROUND

Pharmaceuticals are usually granted a marketing authorisation on the basis of randomised controlled trials (RCTs). Occasionally the efficacy of a treatment is assessed without a randomised comparator group (either active or placebo).

OBJECTIVE

To identify and develop a taxonomic account of economic modelling approaches for pharmaceuticals licensed without RCT data.

METHODS

We searched PubMed, the websites of UK health technology assessment bodies and the International Society for Pharmacoeconomics and Outcomes Research Scientific Presentations Database for assessments of treatments granted a marketing authorisation by the US Food and Drug Administration or European Medicines Agency from January 1999 to May 2014 without RCT data (74 indications). The outcome of interest was the approach to modelling efficacy data.

RESULTS

Fifty-one unique models were identified in 29 peer-reviewed articles, 30 health technology appraisals, and 15 International Society for Pharmacoeconomics and Outcomes Research abstracts concerning 30 indications (44 indications had not been modelled). We noted the high rate of non-submission to health technology assessment agencies (28/98). The majority of models (43/51) were based on 'historical controls'-comparisons to previous meta-analysis or pooling of trials (5), individual trials (16), registries/case series (15), or expert opinion (7). Other approaches used the patient as their own control, performed threshold analysis, assumed time on treatment was added to overall survival, or performed cost-minimisation analysis.

CONCLUSIONS

There is considerable variation in the quality and approach of models constructed for drugs granted a marketing authorisation without a RCT. The most common approach is of a naive comparison to historical data (using other trials/registry data as a control group), which has considerable scope for bias.

Cost-Effectiveness Analysis of Regorafenib for Metastatic Colorectal Cancer

PURPOSE

Regorafenib is a standard-care option for treatment-refractory metastatic colorectal cancer that increases median overall survival by 6 weeks compared with placebo. Given this small incremental clinical benefit, we evaluated the cost-effectiveness of regorafenib in the third-line setting for patients with metastatic colorectal cancer from the US payer perspective.

METHODS

We developed a Markov model to compare the cost and effectiveness of regorafenib with those of placebo in the third-line treatment of metastatic colorectal cancer. Health outcomes were measured in life-years and quality-adjusted life-years (QALYs). Drug costs were based on Medicare reimbursement rates in 2014. Model robustness was addressed in univariable and probabilistic sensitivity analyses.

RESULTS

Regorafenib provided an additional 0.04 QALYs (0.13 life-years) at a cost of $40,000, resulting in an incremental cost-effectiveness ratio of $900,000 per QALY. The incremental cost-effectiveness ratio for regorafenib was > $550,000 per QALY in all of our univariable and probabilistic sensitivity analyses.

CONCLUSION

Regorafenib provides minimal incremental benefit at high incremental cost per QALY in the third-line management of metastatic colorectal cancer. The cost-effectiveness of regorafenib could be improved by the use of value-based pricing.

Role of HGF-MET Signaling in Primary and Acquired Resistance to Targeted Therapies in Cancer

The Hepatocyte growth factor (HGF)-mesenchymal-epithelial transition (MET) pathway is deregulated in several cancers and is associated with aggressive phenotype and worse prognosis. MET, a tyrosine kinase receptor activated by HGF, plays a physiological role in embryogenesis, promoting cell growth, survival and motility. HGF-MET aberrant activation in tumorigenesis acts through various mechanisms: paracrine/autocrine HGF production, MET overexpression, MET germ-line and sporadic mutations and cross-talk with other growth factor receptors. In addition, MET activation could represent a mechanism of escape from other targeted therapies, through receptor amplification or over-stimulation by the ligand, as demonstrated in non-small cell lung cancer (NSCLC) and colorectal cancer (CRC) models with acquired resistance to epidermal growth factor receptor (EGFR) inhibitors and also in models of melanoma resistant to the BRAF inhibitor vemurafenib. As a consequence, a lot of molecules targeting MET signaling are under clinical investigation as single agent or in combination with other targeted drugs. Patient selection, based on MET expression on tumor samples (eventually, by re-biopsy of new metastatic sites), and pharmacokinetic/pharmacodynamic markers are needed. Authors review the latest data on the role of MET and the molecular mechanism underlying primary or acquired resistance to biological agents, focusing on NSCLC, CRC and melanoma.

A systematic review of cost-effectiveness of monoclonal antibodies for metastatic colorectal cancer

Metastatic colorectal cancer (mCRC) imposes a substantial health burden on patients and society. In recent years, advances in the treatment of mCRC have mainly resulted from the introduction of monoclonal antibodies (MoAbs). However, the application of these MoAbs considerably increases treatment costs. The objective of this article is to review and assess the economic evidence of MoAB treatment in mCRC. A systematic literature review was conducted and cost-effectiveness (CE) as well as cost-utility-studies were identified. For this, Medline, Embase, SciSearch, Cochrane, and nine other databases were searched from 2000 through February 2013 for full-text publications. The quality of the studies was assessed via a validated assessment tool (Quality of Health Economic Studies (QHES)). A total of 843 publications were screened. Of those, 15 studies involving the MoAbs bevacizumab, cetuximab and panitumumab met all inclusion criteria. Four studies analysed the CE of first-line treatment with bevacizumab and nine the CE of cetuximab in subsequent treatment lines. Two studies dealt with the CE of panitumumab. The analysis of sequential regimes and the direct comparison of two MoABs were analysed by only one study each. The quality of the included studies was high with the exception of one study.

CONCLUSIONS

The treatment with bevacizumab, cetuximab and panitumumab is mainly considered to be not cost-effective in patients with mCRC. However, testing for Kirsten ras oncogene (KRAS) mutation prior to the treatment with cetuximab or panitumumab is found to be clearly cost-effective compared to no testing. Future research should focus on the CE of first-line treatment with cetuximab or panitumumab and studies on upcoming agents like regorafenib and aflibercept.

Management of colon cancer: resource-stratified guidelines from the Asian Oncology Summit 2012

Colon cancer is seen with increasing frequency in the Asia-Pacific region, and it is one of the most important causes of cancer mortality worldwide. This article reviews the available evidence for optimum management of colon cancer-in particular, with respect to screening and early detection of colon cancer, laparoscopic surgical treatment, adjuvant treatment of individuals with high-risk stage II and stage III cancer, palliative treatment of patients with metastatic disease, and management of resectable and potentially resectable metastases-and how these strategies can be applied in Asian countries with different levels of health-care resources and economic development, stratified by basic, limited, enhanced, and maximum resource levels.

Systematic review and quality assessment of cost-effectiveness analysis of pharmaceutical therapies for advanced colorectal cancer

OBJECTIVE

To systematically review and assess the quality of cost-effectiveness analyses (CEAs) of pharmaceutical therapies for metastatic colorectal cancer (mCRC).

DATA SOURCES

The MEDLINE, EMBASE, Cochrane, and EconLit databases were searched for the Medical Subject Headings or text key words quality-adjusted, QALY, life-year gained (LYG), and cost-effectiveness (January 1, 1999-December 31, 2009).

STUDY SELECTION

Original CEAs of mCRC pharmacotherapy published in English were included. CEAs that measured health effects in units other than quality-adjusted life years or LYG and letters to the editor, case reports, posters, and editorials were excluded.

DATA EXTRACTION

Each article was independently assessed by 2 trained reviewers according to a quality checklist created by the Panel on Cost-Effectiveness in Health and Medicine.

RESULTS

Twenty-four CEA studies pertaining to pharmaceutical therapies for mCRC were identified. All studies showed a wide variation in methodologic approaches, which resulted in a different range of incremental cost-effectiveness ratios reported for each regimen. We found common methodologic flaws in a significant number of CEA studies, including lack of clear description for critique of data quality; lack of method for adjusting costs for inflation and methods for obtaining expert judgment; no results of model validation; wide differences in the types of perspective, time horizon, study design, cost categories, and effect outcomes; and no quality assessment of data (cost and effectiveness) for the interventions evaluation.

CONCLUSIONS

This study has shown a wide variation in the methodology and quality of cost-effectiveness analysis for mCRC. Improving quality and harmonization of CEA for cancer treatment is needed. Further study is suggested to assess the quality of CEA methodology outside the mCRC disease state.

Influence of pharmacogenomic profiling prior to pharmaceutical treatment in metastatic colorectal cancer on cost effectiveness : a systematic review

BACKGROUND

Metastatic colorectal cancer (mCRC) imposes a substantial health burden on individual patients and society. Furthermore, rising costs in oncology cause a growing concern about reimbursement for innovations in this sector. The promise of pharmacogenomic profiling and related stratified therapies in mCRC is to improve treatment efficacy and potentially save costs. Among other examples, the commonly used epidermal growth factor receptor (EGFR) antibodies cetuximab and panitumumab are only effective in patients with kirsten rat sarcoma viral oncogene homolog (KRAS) wild-type cancers. Hence, the adaptation of predictive biomarker testing might be a valid strategy for healthcare systems worldwide.

OBJECTIVE

This study aims to review the clinical and economic evidence supporting pharmacogenomic profiling prior to the administration of pharmaceutical treatment in mCRC. Moreover, key drivers and areas of uncertainty in cost-effectiveness evaluations are analysed.

METHODS

A systematic literature review was conducted to identify studies evaluating the cost effectiveness of predictive biomarkers and the result dependent usage of pharmaceutical agents in mCRC.

RESULTS

The application of predictive biomarkers to detect KRAS mutations prior to the administration of EGFR antibodies saved treatment costs and was cost effective in all identified evaluations. However, because of the lack of data regarding cost-effectiveness analyses for predictive biomarker testing, e.g. for first-line treatment, definitive conclusions cannot be stated. Key drivers and areas of uncertainty in current cost-effectiveness analyses are, among others, the consideration of predictive biomarker costs, the characteristics of single predictive biomarkers and the availability of clinical data for the respective pharmaceutical intervention. Especially the cost effectiveness of uridine diphosphate-glucuronyl transferase 1A1 (UGT1A1) mutation analysis prior to irinotecan-based chemotherapy remains unclear.

CONCLUSION

Pharmacogenomic profiling has the potential to improve the cost effectiveness of pharmaceutical treatment in mCRC. Hence, quantification of the economic impact of stratified medicine as well as cost-effectiveness analyses of pharmacogenomic profiling are becoming more important. Nevertheless, the methods applied in cost-effectiveness evaluations for the usage of predictive biomarkers for patient selection as well as the level of evidence required to determine clinical effectiveness are areas for further research. However, mCRC is one of the first indications in which stratified therapies are used in clinical practice. Thus, clinical and economic experiences could be helpful when adopting pharmacogenomic profiling into clinical practice for other indications.

Gene silencing of EREG mediated by DNA methylation and histone modification in human gastric cancers

Epiregulin (EREG) induces cell growth by binding to the epidermal growth factor receptor (EGFR). Expression of EREG affects sensitivity to cetuximab a chimeric monoclonal antibody that inhibits the EGFR signaling pathway. The mechanism through which EREG is regulated is largely unknown, but a methyl-array study previously performed by our group revealed that EREG is methylated in gastric cancer cells. In this study, we found that EREG gene expression was low in 7 out of 11 gastric cancer cells and this downregulation was mediated by aberrant CpG methylation of the EREG promoter. Treatment with 5-aza-CdR restored EREG expression and demethylated CpG sites in the EREG promoter. Compared with DNA methyltransferase 1 (DNMT1), knock-down of DNA methyltransferase 3b (DNMT3b) significantly increased the expression of EREG and led to the demethylation of specific CpG sites in the EREG promoter, suggesting that DNMT3b primarily regulates CpG methylation and silencing of the EREG gene. EREG methylation was observed in 30% (4/13) of human primary gastric tumor tissues we evaluated. In addition to DNA methylation, results from a chromatin immunoprecipitation assay demonstrated that transcriptional levels of EREG were associated with the enrichment of active histone marks (H3K4me3 and AcH3) and of a repressive mark (H3K27me2). Treatment with 5-aza-CdR dynamically increased the low occupancy of H3K4me3 and AcH3, while decreasing the high enrichment of H3K27me2, indicating that dynamic histone modifications contribute to EREG regulation in addition to DNA methylation. Finally, the combination of 5-aza-CdR and cetuximab exerted a synergistic anti-proliferative effect on gastric cancer cells. Taken together, the results of our study showed for the first time that EREG is epigenetically silenced in gastric cancer cells by aberrant DNA methylation and histone modification.

The current state of targeted agents in rectal cancer

Targeted biologic agents have an established role in treating metastatic colorectal cancer (CRC), and the integration of targeted therapies into the treatment of CRC has resulted in significant improvements in outcomes. Rapidly growing insight into the molecular biology of CRC, as well as recent developments in gene sequencing and molecular diagnostics, has led to high expectations for the identification of molecular markers to be used in personalized treatment regimens. The mechanisms of action and toxicities of targeted therapies differ from those of traditional cytotoxic chemotherapy. Targeted therapy has raised new insight about the possibility of tailoring treatment to an individual's disease, the assessment of drug effectiveness and toxicity, and the economics of cancer care. This paper covers the last decade of clinical trials that have explored the toxicity and efficacy of targeted agents in locally advanced and metastatic CRC and how their role may benefit patients with rectal cancer. Future efforts should include prospective studies of these agents in biomarker-defined subpopulations, as well as studies of novel agents that target angiogenesis, tumor-stromal interaction, and the cell signaling pathways implicated in rectal cancer.

Cost-effectiveness of KRAS testing in metastatic colorectal cancer patients in the United States and Germany

The objective of this study was to determine the cost-effectiveness of testing for KRAS mutations before administering EGFR inhibitors such as cetuximab and panitumumab for patients with advanced metastatic colorectal cancer (mCRC) in the United States and Germany. We developed a lifetime Markov model of costs and survival associated with treating mCRC patients to assess the impact of KRAS testing before administering EGFR inhibitor-containing chemotherapy regimens. Overall, combination therapies involving cetuximab plus irinotecan/FOLFIRI had a better life expectancy (25.83 weeks) than cetuximab or panitumumab alone. Use of KRAS testing (assuming KRAS mutant patients receive only irinotecan) was equally effective and saved $12,428 per patient in the United States. When KRAS mutant patients received best supportive care, the life expectancy decreased slightly (24.26 weeks vs. 25.83 weeks) and the costs decreased by $13,501 in the United States and €9,560 in Germany. For patients treated with cetuximab alone, use of KRAS testing to identify mutations lowered costs by $8,040 per patient in the U.S. analysis and €3,856 per patient in the German analysis. For patients treated with panitumumab alone, use of KRAS testing to identify mutations lowered costs by $7,546 per patient in the U.S. analysis and €4,612 per patient in the German analysis. Model results were sensitive to the cost of chemotherapy regimens and the prevalence of KRAS mutations in the population. Under most scenarios, using KRAS testing to select patients for EGFR inhibitor therapy saved $7,500-$12,400 per patient in the United States and €3,900-€9,600 per patient in Germany with equivalent clinical outcomes.

The evolving role of monoclonal antibodies in colorectal cancer: early presumptions and impact on clinical trial development

Targeted biologic agents have an established role in treating metastatic colorectal cancer (mCRC). Bevacizumab, a recombinant monoclonal antibody against the vascular endothelial growth factor ligand is approved by the U.S. Food and Drug Administration (FDA) for bevacizumab-naïve patients. Cetuximab, a chimeric monoclonal antibody (mAb) against the epidermal growth factor receptor (EGFR) is FDA approved as a single agent, or in combination with irinotecan, in both irinotecan-naïve and refractory patients, and has additional efficacy in combination with oxaliplatin. Panitumumab, a fully human EGFR mAb, is FDA approved as a single agent in refractory patients but has additional efficacy in combination with chemotherapy. After reaching a temporary therapeutic plateau of FDA-approved agents for the treatment of mCRC, pivotal results have developed that critically affect the care for these patients. Correlative data from randomized trials of EGFR inhibitors across disease settings have demonstrated higher response rates, specifically for patients with wild-type K-RAS tumors. The interpretation of the B-RAF mutation and other molecular markers may further define the appropriateness of anti-EGFR therapy. Recent literature revealed that the first-line use of combined anti-EGFR therapy plus bevacizumab resulted in inferior outcomes and additional toxicities. Furthermore, the role of biologic agents for locally advanced colon cancer cannot be advocated at this time. With impending changes in the health care system, the economic impact of mAbs will continue to be scrutinized. Hence, as the significance of molecular markers continues to develop, their role as it pertains to the appropriate use of biologic agents in the treatment of mCRC will continue to evolve.