A within-trial cost-effectiveness analysis of panitumumab compared with bevacizumab in the first-line treatment of patients with wild-type RAS metastatic colorectal cancer in the US

Projecting overall survival in health-economic models: uncertainty and maturity of data

OBJECTIVE

As lifetime horizons are considered for economic evaluations, the Kaplan-Meier (KM) estimate is used to extrapolate survival in cases of immature overall survival (OS) data. This study estimated the error induced by the choice of distribution when extrapolating different levels of OS maturity.

METHODS

Fifteen phase 3 trials reporting KM estimates of OS where at least 70% maturity (i.e. 70% of the population had died during follow-up) were included and compared to artificially created truncated data (30 and 50% maturity). Individual patient-data were reproduced using the Guyot algorithm based on digitized KM curves. Parametric survival distributions were fit for each arm in each study, for each maturity level, using the same time horizon (equal to the maximum follow-up). For each KM curve, the best distribution was chosen based on visual inspection, Akaike/Bayesian information criteria, and external validity. Outcomes were measured as life expectancy in months (LM) and life months gained (LMG).

RESULTS

The Weibull (33%), log-logistic (32%) and log-normal (27%) were most often selected as the best fitting distribution. Compared to LM at full maturity, LM was overestimated in 23 and 40% of cases, at 30 and 50% maturity, respectively. Mean absolute error was 2.12months at 30% maturity, and decreased to 0.88months at 50% maturity. When comparing to mature data, the mean percentage of error in LMG was 126.4 and 62.4% at 30 and 50% maturity, respectively.

CONCLUSION

The extent of OS maturity increases the risk of error when projecting long-term life expectancy for economic models. Even marginal gains in OS maturity result in more accurate estimations and should be considered when developing models.

Cost-effectiveness Analysis of Monoclonal Antibodies in the First-line Treatment of RAS Wild-type Metastatic Colorectal Cancer: A Systematic Review

PURPOSE

First-line treatment with monoclonal antibodies (bevacizumab, cetuximab, and panitumumab) for RAS wild-type metastatic colorectal cancer (mCRC) has advanced. The costs of drugs targeted to mCRC are high. This systematic review aimed to summarize the cost-effectiveness of monoclonal antibodies in the first-line treatment of RAS wild-type mCRC.

METHODS

We searched 5 databases to find original-research cost-effectiveness analyses of monoclonal antibodies used in the first-line treatment of patients with RAS wild-type mCRC. Three reviewers independently evaluated all of the records to be screened.

FINDINGS

A total of 15 articles, 12 cost-effectiveness analyses, and 3 cost-utility analyses were identified. The reporting of identified articles was assessed using the Consolidated Health Economic Evaluation Reporting Standards 2022 checklist. They were assigned to 1 of 6 categories based on the combination of the intervention and control groups, the most common of which was cetuximab + chemotherapy versus bevacizumab + chemotherapy. The results of the cost-effectiveness analyses may have varied because of the differences in settings, such as country, study population, RAS mutation status, efficacy data, and model structure, in which each study was conducted.

IMPLICATIONS

Although treatment with monoclonal antibodies has demonstrated efficacy in terms of life-years gained and progression-free survival, the most cost-effective treatment among monoclonal antibodies remains controversial; however, most of the studies that compared a monoclonal antibody + chemotherapy versus chemotherapy alone reported that chemotherapy alone was a cost-effective strategy. Future studies are needed to evaluate the cost-effectiveness of treating patients with mCRC using biomarker-driven precision medicine.

Economic Evaluation of Monoclonal Antibodies in Metastatic Colorectal Cancer: A Systematic Review

INTRODUCTION

Colorectal cancer (CRC) is one of the major causes of mortality and morbidity worldwide. The median overall survival (OS) of patients with metastatic CRC (mCRC) has doubled over the last 20 years partly due to the introduction of advanced biologic therapies. However, these treatment modalities bear significant costs on healthcare systems globally, and may jeopardize their fiscal sustainability. The aim of this systematic review was to critically appraise the economic evaluations of monoclonal antibodies in mCRC.

METHODOLOGY

A literature search was performed in the electronic databases of: Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, EMBASE, EMBASE Alert, PUBMED, NHS Economic Evaluation and Health Technology Assessment Database for full articles published from 1 January 2013 to 31 December 2020.

RESULTS

Twenty economic analyses were identified in the literature that fulfilled the inclusion criteria and evaluated the cost-effectiveness of (a) bevacizumab as first-line treatment for mCRC and as maintenance treatment, (b) cetuximab as first-line treatment, (c) panitumumab versus bevacizumab and cetuximab versus bevacizumab as first-line treatment, (d) aflibercept and ramucirumab as second-line treatment, (e) cetuximab and panitumumab as third-line treatment, (f) cetuximab versus panitumumab as later lines of treatment, and (g) RAS testing prior to anti-epidermal growth factor receptor (EGFR) treatment.

CONCLUSIONS

Bevacizumab in combination with chemotherapy is cost-effective as neither first-line treatment nor maintenance treatment. Sequential treatment with bevacizumab in first-line and second-line treatment was also not cost-effective. Testing for KRAS and extended RAS mutations is cost-effective and should be performed prior to anti-EGFR treatment. In the RAS wild-type subgroup of mCRCs the use of anti-EGFR (panitumumab or cetuximab) in first-line treatment leads to a more favorable cost-effectiveness profile than the corresponding anti-VEGF (bevacizumab). Cetuximab is not cost-effective as a first-line treatment. Anti-EGFR administration is not a cost-effective strategy in third-line treatment, even for RAS wild-type mCRCs, compared to best supportive care. Aflibercept was superior to ramucirumab and costed less, but neither were cost-effective compared to standard care.

Cost-Effectiveness of Anti-Epidermal Growth Factor Receptor Therapy Versus Bevacizumab in KRAS Wild-Type (WT), Pan-RAS WT, and Pan-RAS WT Left-Sided Metastatic Colorectal Cancer

Objectives

We aimed to compare the economic value of chemotherapy plus anti-epidermal growth factor receptor (anti-EGFR) monoclonal antibody (mAb) against chemotherapy with bevacizumab (Bev, an anti-vascular endothelial growth factor mAb) as first-line treatment in KRAS wild-type (WT), pan-RAS WT and pan-RAS WT left-sided metastatic colorectal cancer (mCRC) patients from the Hong Kong societal perspective.

Materials and Methods

We developed Markov models and 10-year horizon to estimate costs, quality-adjusted life years (QALYs), and incremental cost-effectiveness ratio (ICER) of chemotherapy plus anti-EGFR therapy against chemotherapy plus Bev in KRAS WT, pan-RAS WT, and pan-RAS WT left-sided mCRC. We considered two times of the local gross domestic product per capita (GDPpc) as the willingness-to-pay (WTP) threshold (2× GDPpc; US$97,832).

Results

Adding anti-EGFR mAb to chemotherapy provides additional 0.24 (95% confidence interval [CI] 0.19-0.29), 0.32 (95% CI 0.27-0.37), and 0.57 (95% CI 0.49-0.63) QALY compared to adding Bev in KRAS WT, pan-RAS WT, and left-sided pan-RAS WT mCRC populations respectively. The corresponding ICER is US$106,847 (95% CI 87,806-134,523), US$88,565 (95% CI 75,678-105,871), US$76,537 (95% CI 67,794-87,917) per QALY gained, respectively.

Conclusions

Anti-EGFR therapy is more cost-effective than Bev as a first-line targeted therapy in left-sided pan-RAS WT and pan-RAS WT, with ICER <US$100,000/QALY, compared to KRAS WT mCRC population.

Colon Cancer, Version 2.2021, NCCN Clinical Practice Guidelines in Oncology

This selection from the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Colon Cancer focuses on systemic therapy options for the treatment of metastatic colorectal cancer (mCRC), because important updates have recently been made to this section. These updates include recommendations for first-line use of checkpoint inhibitors for mCRC, that is deficient mismatch repair/microsatellite instability-high, recommendations related to the use of biosimilars, and expanded recommendations for biomarker testing. The systemic therapy recommendations now include targeted therapy options for patients with mCRC that is HER2-amplified, or BRAF V600E mutation-positive. Treatment and management of nonmetastatic or resectable/ablatable metastatic disease are discussed in the complete version of the NCCN Guidelines for Colon Cancer available at NCCN.org. Additional topics covered in the complete version include risk assessment, staging, pathology, posttreatment surveillance, and survivorship.

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.

CAR-T therapy and historical trends in effectiveness and cost–effectiveness of oncology treatments

Aim: This study examines how chimeric antigen receptor T-cell (CAR-T) therapy’s incremental effectiveness and cost–effectiveness profile fits into the recent history of anticancer treatments. Materials & methods: We conducted graphical and multivariable analyses using data from the Cost–Effectiveness Analysis Registry of the Tufts Medical Center and the Institute for Clinical and Economic Review’s analysis of CAR-T therapies. We collected additional information including the US FDA approval years for pharmacologic innovations. Results: CAR-T provided 5.03 (95% CI: 3.88–6.18) more incremental quality-adjusted life-years than the average pharmaceutical intervention and 4.61 (95% CI: 1.67–7.56) more than the average nonpharmaceutical intervention, while retaining similar cost–effectiveness. There was evidence of worsening cost–effectiveness by approval year for pharmaceutical interventions. Limitations: Analysis is limited to anticancer treatments studied in cost–utility analyses, estimated to cover approximately 60% of FDA-approved antineoplastic agents. Conclusion: CAR-T therapy breaks a pattern of stagnant efficacy growth in pharmaceutical innovation and demonstrates significantly greater incremental effectiveness and similar cost–effectiveness to prior innovations.