Positive spillover effects of prescribing requirements: increased cardiac testing in patients treated with trastuzumab for HER2+ metastatic breast cancer

Cardiac assessment in Australian patients receiving (neo)adjuvant trastuzumab for HER2-positive early breast cancer: a population-based study

PURPOSE

Cardiac function assessment is important for detecting and managing trastuzumab-associated cardiotoxicity. Our study estimates rates and predictors of cardiac assessment among patients receiving trastuzumab for HER2-positive early breast cancer (HER2+EBC) in Australia.

METHODS

We conducted a retrospective cohort study of Australians initiating (neo)adjuvant trastuzumab for HER2+EBC between 1 January 2015 and 15 April 2019. We used administrative claims to determine the number of patients receiving guideline-recommended assessment, i.e. evidence of baseline cardiac assessment (between 120 days before and 30 days after trastuzumab initiation) and regular on-treatment cardiac assessments (at least every 120 days). We examined factors associated with baseline and regular on-treatment cardiac assessment.

RESULTS

Our study includes 5621 patients (median age 56 years), of whom 4984 (88.7%) had a baseline cardiac function test. Among 4280 patients with at least 12 months of follow-up, 2702 (63.1%) had guideline-recommended cardiac assessment. Rates of guideline-recommended assessment increased with later year of diagnosis (60.9% in 2015 vs 68.3% in 2018, OR 1.34, 95% CI 1.06-1.69). Patients with higher baseline comorbidities and greater socioeconomic disadvantage were less likely to have guideline-recommended cardiac assessment. Cardiac assessment practices varied by State/Territory. There was no association between baseline cardiac risk or anthracycline use and the likelihood of receiving guideline-recommended cardiac assessment.

CONCLUSION

The majority of patients receiving (neo)adjuvant trastuzumab had guideline-recommended baseline and on-treatment cardiac assessment. Variations in cardiac assessment predominantly related to system-level factors, such as year of diagnosis and geography, rather than individual patient factors.

Association of Utilization Management Policy With Uptake of Hypofractionated Radiotherapy Among Patients With Early-Stage Breast Cancer

Importance

Breast cancer accounts for the largest portion of cancer-related spending in the United States. Although hypofractionated radiotherapy after breast-conserving surgery is a cost-effective and convenient treatment strategy for patients with early-stage breast cancer, less than 40% of eligible women received hypofractionated radiotherapy in 2013.

Objective

To assess the association of a large commercial payer's utilization management policy with the use of hypofractionated radiotherapy among women with early-stage breast cancer and its associated cost.

Design, Setting, and Participants

A retrospective, adjusted difference-in-differences economic analysis was conducted using administrative claims data from January 1, 2012, to June 1, 2018, of women 18 years or older with early-stage breast cancer who were eligible for hypofractionated radiotherapy according to 2011 guidelines from the American Society for Radiation Oncology and were continuously enrolled in 14 geographically diverse commercial health plans covering 6.9% of US adult women. Women who received mastectomy, brachytherapy, or less than 11 or more than 40 external beam fractions of radiotherapy were excluded. A utilization management policy was used to encourage the use of hypofractionated radiotherapy among women in fully insured and Medicare Advantage (fully insured) plans. Under the new policy, claims for extended-course radiotherapy were not reimbursed for fully insured women who were eligible for hypofractionated radiotherapy. This policy did not apply to women in self-insured or Medicare supplemental insurance (self-insured) plans, allowing these groups to serve as a comparison group.

Main Outcomes and Measures

The primary outcome was use of hypofractionated radiotherapy, and the secondary outcome was the cost of this type of radiotherapy.

Results

Of 10 540 eligible women, 3619 (34.3%) were in fully insured plans and thus subject to the policy. There were no meaningful differences between the fully insured and self-insured groups in mean (SD) age at the start of radiotherapy (63.8 [8.6] vs 65.0 [8.9] years), mean (SD) Charlson Comorbidity Index score (3.0 [1.5] vs 3.2 [1.6]), or practice setting (outpatient hospital setting, 2982 of 3619 [82.4%] vs 5600 of 6921 [80.9%]). The policy was associated with an increase in use of hypofractionated radiotherapy among fully insured patients subject to the policy (adjusted percentage point difference-in-difference, 4.2%; 95% CI, 0.0%-8.4%; P = .05) and a nonsignificant decrease in radiotherapy-associated expenditures (-$2275 relative to self-insured patients; P = .09). Spillover analyses revealed a significantly higher uptake of hypofractionated radiotherapy among self-insured patients who were indirectly exposed to the policy (adjusted percentage point difference-in-difference, 8.5%; 95% CI, 3.6%-13.5%; P < .001) compared with those who were not exposed.

Conclusions and Relevance

This study suggests that a payer's utilization management policy was associated with direct and spillover increases in the use of hypofractionated radiotherapy, even after accounting for a long-term secular trend in the uptake of hypofractionated radiotherapy in the control groups. Utilization management may promote evidence-based cancer care.

Trastuzumab use in older patients with HER2-positive metastatic breast cancer: outcomes and treatment patterns in a whole-of-population Australian cohort (2003-2015)

Background

Older patients with HER2-positive metastatic breast (HER2 + MBC) cancer are underrepresented in clinical trials. We aim to describe the treatment patterns and overall survival (OS) for older women receiving trastuzumab for HER2 + MBC.

Methods

Retrospective, whole-of-population cohort study using demographic, dispensing, and medical services data for Australian women ≥ 65 years initiating trastuzumab for HER2 + MBC between 2003 and 2015. We describe time-on-trastuzumab; type and timing of other cancer treatments; rates of cardiac monitoring; and OS from trastuzumab initiation for HER2 + MBC.

Results

Of 5404 women initiating trastuzumab for HER2 + MBC, 1583 (29%) were ≥ 65 years old, and the proportion of older patients increased from 20% in 2003 to 38% in 2015. The median age for older women was 73 years and 516 (33%) were ≥ 75 years. Most older patients (92%) received ≥3medicines for comorbidities other than cancer. Median (IQR) time on trastuzumab was 14.1 months (5.9–32.1) and on all chemotherapy was 5.6 months (3.3–10.8). 74% received ≥1 chemotherapy agent and 56% received endocrine therapy. Half (49%) of patients had a cardiac assessment prior to initiating trastuzumab and overall 1228 (76%) had ≥1 cardiac assessment during the study period. At a median follow-up of 6 years, 73% of patients had died and the median OS was 25.6 months (IQR 10.7–58.7).

Conclusions

Older patients comprise a growing proportion of patients treated with HER2-targeted therapies in the real-world but they remain underrepresented in trials of these agents. Few trials report duration or OS estimates for older patients but our estimates are similar to those from trials that have. Although cardiac monitoring was a requirement of accessing trastuzumab during our study period, many patients did not undergo a cardiac assessment.

Trastuzumab for metastatic breast cancer: Real world outcomes from an Australian whole-of-population cohort (2001-2016)

PURPOSE

Outcomes for patients treated in clinical trials may not reflect the experience in routine clinical care. We aim to describe the real-world treatment patterns and overall survival (OS) for women receiving trastuzumab for metastatic breast cancer (MBC).

METHODS

Retrospective, whole-of-population cohort study using demographic, dispensing, and medical services data for women in the Herceptin Program for HER2+MBC. We estimated time on trastuzumab and OS from first dispensing of trastuzumab for MBC and rates of cardiac monitoring prior to and during treatment. We stratified outcomes by two groups based on year of initiation: 2001-2008 and 2009-2015. We benchmarked outcomes to two key trastuzumab clinical trials: H0648g (median OS 25 months) and CLEOPATRA (control group median OS 41 months).

RESULTS

Median age of the 5899 women at first trastuzumab dispensing was 57 years (interquartile range [IQR]: 48-66). Median time on trastuzumab increased from 15 months (7-33) in Group One to 18 months (8-42) in Group Two. Median OS increased from 27 months (12-57) in Group One to 38 months (16-83) in Group Two. Rates of cardiac monitoring increased at baseline (52%-76%), and on-treatment (47%-67%), in Group One and Two, respectively.

CONCLUSIONS

OS, duration of trastuzumab, and frequency of cardiac monitoring increased over the study period. Outcomes for trastuzumab in this heterogeneous real world population were reassuringly comparable to those from clinical trials, with the median OS > 3 years in Group Two and 25% of patients living 7 years or longer.

Geographic Variations and Time Trends in Cancer Treatments in Taiwan

Background

Targeted therapies have become important treatment options for cancer care in many countries. This study aimed to examine recent trends in utilization of antineoplastic drugs, particularly the use of targeted therapies for treatment of cancer, by geographic region in Taiwan (northern, midwestern, southern, and eastern regions and the outer islands).

Methods

This was a retrospective observational study of antineoplastic agents using 2009-2012 quarterly claims data from Taiwan’s National Health Insurance Research Database. Yearly market shares by prescription volume and costs for targeted therapies among total antineoplastic agents by region were estimated. We used multivariate regression model and ANOVA to examine variations in utilization of targeted therapies between geographic regions and used ARIMA models to estimate longitudinal trends.

Results

Population-adjusted use and costs of antineoplastic drugs (including targeted therapies) were highest in the southern region of Taiwan and lowest in the outer islands. We found a 4-fold difference in use of antineoplastic drugs and a 49-fold difference in use of targeted therapies between regions if the outer islands were included. There were minimal differences in use of antineoplastic drugs between other regions with about a 2-fold difference in use of targeted therapies. Without considering the outer islands, the market share by prescription volume and costs of targeted therapies increased almost 2-fold (1.84-1.90) and 1.5-fold (1.26-1.61) respectively between 2009 and 2012. Furthermore, region was not significantly associated with use of antineoplastic agents or use of targeted therapies after adjusting for confounders. Region was associated with costs of antineoplastic agents but it was not associated with costs of targeted therapies after confounding adjustments.

Conclusions

Use of antineoplastic drugs overall and use of targeted therapies for treatment of cancer varied somewhat between regions in Taiwan; use was notably low in the outer islands. Strategies might be needed to ensure access to cancer care in each region as economic burden of cancer care increase due to growing use of targeted therapies.

Use and outcomes of targeted therapies in early and metastatic HER2-positive breast cancer in Australia: protocol detailing observations in a whole of population cohort

BACKGROUND

The management of human epidermal growth factor receptor 2 (HER2)-positive breast cancer (BC) has changed dramatically with the introduction and widespread use of HER2-targeted therapies. However, there is relatively limited real-world information on patterns of use, effectiveness and safety in whole of population cohorts. The research programme detailed in this protocol will generate evidence on the prescribing patterns, safety monitoring and outcomes of patients with BC treated with HER2-targeted therapies in Australia.

METHODS/DESIGN

Our ongoing research programme will involve a series of retrospective cohort studies that include every patient accessing Commonwealth-funded HER2-targeted therapies for the treatment of early BC and advanced BC in Australia. At the time of writing, our cohorts consist of 11 406 patients with early BC and 5631 with advanced BC who accessed trastuzumab and lapatinib between 2001 and 2014. Pertuzumab and trastuzumab emtansine were publicly funded for metastatic BC in 2015, and future data updates will include patients accessing these medicines. We will use dispensing claims for cancer and other medicines, medical service claims and demographics data for each patient accessing HER2-targeted therapies to undertake this research.

ETHICS AND DISSEMINATION

Ethics approval has been granted by the Population Health Service Research Ethics Committee and data access approval has been granted by the Australian Department of Human Services (DHS) External Review Evaluation Committee. Our findings will be reported in peer-reviewed publications, conference presentations and policy forums. By providing detailed information on the use and outcomes associated with HER2-targeted therapies in a national cohort treated in routine clinical care, our research programme will better inform clinicians and patients about the real-world use of these treatments and will assist third-party payers to better understand the use and economic costs of these treatments.

Real-World Evidence: A Comparison of the Australian Herceptin Program and Clinical Trials of Trastuzumab for HER2-Positive Metastatic Breast Cancer

INTRODUCTION

Estimating the real-world cost-effectiveness of a new drug relies on understanding the differences between clinical trial data (pre-reimbursement) and clinical practice (post-reimbursement). This is important for decision makers when reviewing reimbursement decisions, prices, and considering other drugs for the same condition. Differences can arise from differences in patient characteristics, but also from the availability of new evidence and evolving treatment practices. This paper examines these issues using a case study.

METHODS

In 2001, the Australian Government funded trastuzumab for the treatment of HER2+ metastatic breast cancer through the Herceptin Program. The administrative arrangements of the Program resulted in rich observational data that captured information about patients treated with trastuzumab between 2001 and 2010 (n = 3830). The dataset included patient characteristics, dispensed medicines, medical service use and date of death.

RESULTS

Compared to participants in the clinical trials, patients were older, received more prior chemotherapies and a broader range of co-administered chemotherapies. Treatment practices differed from the clinical trials, but also changed over time. For example, in situ hybridization testing, rather than immunohistochemistry testing, and a three weekly administration schedule, rather than one weekly, were increasingly used. Compared to the clinical trials, patients administered trastuzumab with a concomitant chemotherapy generally experienced longer overall survival (151.3 weeks, 95 % CI: 142.6, 163.4), while those who received trastuzumab as a monotherapy experienced shorter overall survival (94.4 weeks, 95%CI: 86.4, 102.9). These findings may be due to a differing relative treatment effect in clinical practice, but may also be due to a range of other factors.

CONCLUSION

This analysis demonstrates the challenges for decision makers that arise because new evidence and evolving treatment practices create a gap between clinical trial data and real-world clinical practice and outcomes.

Longitudinal trends in use and costs of targeted therapies for common cancers in Taiwan: a retrospective observational study

OBJECTIVES

Some targeted therapies have improved survival and overall quality of cancer care generally, but these increasingly expensive medicines have led to increases in pharmaceutical expenditure. This study examined trends in use and expenditures of antineoplastic agents in Taiwan, and estimated market shares by prescription volume and costs of targeted therapies over time. We also determined which cancer types accounted for the highest use of targeted therapies.

DESIGN

This is a retrospective observational study focusing on the utilisation of targeted therapies for treatment of cancer.

SETTING

The monthly claims data for antineoplastic agents were retrieved from Taiwan's National Health Insurance Research Database (2009-2012).

MAIN OUTCOME MEASURES

We calculated market shares by prescription volume and costs for each class of antineoplastic agent by cancer type. Using a time series design with Autoregressive Integrated Moving Average (ARIMA) models, we estimated trends in use and costs of targeted therapies.

RESULTS

Among all antineoplastic agents, use of targeted therapies grew from 6.24% in 2009 to 12.29% in 2012, but their costs rose from 26.16% to 41.57% in that time. Monoclonal antibodies and protein kinase inhibitors contributed the most (respectively, 23.84% and 16.12% of costs for antineoplastic agents in 2012). During 2009-2012, lung (44.64% of use; 28.26% of costs), female breast (16.49% of use; 27.18% of costs) and colorectal (12.11% of use; 13.16% of costs) cancers accounted for the highest use of targeted therapies.

CONCLUSIONS

In Taiwan, targeted therapies are increasingly used for different cancers, representing a substantial economic burden. It is important to establish mechanisms to monitor their use and outcomes.

Longitudinal trends in use of targeted therapies for treatment of malignant neoplasms of the eye: a population-based study in Taiwan

OBJECTIVES

This study examined the recent trend in use and costs of antineoplastic agents for treatment of eye malignancies in Taiwan from 2009 to 2012. We also forecasted use and costs of targeted therapies up to and including year 2016 based on the current patterns.

DESIGN

Retrospective observational study focusing on the usage of targeted therapies for treatment of eye malignancy.

SETTING

The monthly claims data for eye malignancy-related antineoplastic agents were retrieved from Taiwan's National Health Insurance Research Database (2009-2012).

MAIN OUTCOME MEASURES

We calculated the number of prescriptions and costs for each class of medications, and analysed their time trends. In addition, using a time series design with ARIMA models, we estimated the market share by prescription volume and the proportion of costs for targeted therapies for year 2016.

RESULTS

The market share by prescription volume of targeted therapies grew from 1.56% in 2009 to 9.98% in 2012 among all antineoplastic agents, and the proportion of costs for targeted therapies rose from 15.12% in 2009 to 58.88% in 2012. Especially, the proportion of costs for protein kinase inhibitors grew from 25.62% to 45.28% among all antineoplastic agents between 2010 and 2012. The market share by prescription volume and the proportion of costs for targeted therapies for treatment of eye malignancies were predicted to reach 27.33% and 91.39% by the fourth quarter in 2016, respectively.

CONCLUSIONS

This is the first study that examined and forecasted use and costs of targeted therapies for treatment of eye malignancies in Taiwan. Our findings indicate that, compared with other classes of drugs, targeted therapies are having a more and more relevant share among all treatment strategies for eye malignancies in Taiwan, and due to their high costs they are likely to cause great economic burden.

The role of general nuclear medicine in breast cancer

The rising incidence of breast cancer worldwide has prompted many improvements to current care. Routine nuclear medicine is a major contributor to a full gamut of clinical studies such as early lesion detection and stratification; guiding, monitoring, and predicting response to therapy; and monitoring progression, recurrence or metastases. Developments in instrumentation such as the high-resolution dedicated breast device coupled with the diagnostic versatility of conventional cameras have reinserted nuclear medicine as a valuable tool in the broader clinical setting. This review outlines the role of general nuclear medicine, concluding that targeted radiopharmaceuticals and versatile instrumentation position nuclear medicine as a powerful modality for patients with breast cancer.

Economic evaluations of trastuzumab in HER2-positive metastatic breast cancer: a systematic review and critique

BACKGROUND

Published economic evaluations of trastuzumab for the treatment of HER2-positive metastatic breast cancer have arrived at different conclusions regarding the cost-effectiveness of trastuzumab, despite comparative efficacy being demonstrated by a small set of randomised controlled trials (RCTs).

OBJECTIVES

This article aims to provide insight into the quality of the evaluations and explore the possible drivers of the conflicting conclusions.

METHODS

A systematic literature review was conducted to identify all published economic evaluations that compared the incremental costs and outcomes of trastuzumab versus a comparator.

RESULTS

Fifteen economic evaluations were identified. In the evaluations that estimated efficacy using an RCT, the key drivers of the conclusions regarding cost-effectiveness were: the approach used to estimate overall survival in the control group given crossover to trastuzumab following progression in the trials; the inclusion of treatment beyond progression; inclusion of wastage due to unused vial portions, adverse events, and the cost of HER2 testing. Four evaluations used non-randomised approaches to estimate efficacy, thus introducing the potential for confounding. As a result these evaluations reported relatively optimistic estimates of comparative effectiveness. Finally the evaluations used different thresholds to determine whether treatment with trastuzumab was cost-effective.

CONCLUSION

There were numerous drivers of the different conclusions regarding the cost-effectiveness of trastuzumab, many of which are due to judgements made by the authors when translating data from RCTs. Many of the potential drivers were not identified by the published systematic reviews of economic evaluations and perhaps more remain unidentified because of inconsistent and limited reporting.

Breast cancer therapies and cardiomyopathy

The prevalence of chemotherapy-related cardiac disease is increasing and management demands a multidisciplinary approach from cardiologists and oncologists. Pretreatment identification of predisposing risk factors and assessment of cardiac function before and at intervals during and after therapy with cardiotoxic agents are necessary. In clinical practice, surveillance is largely performed using transthoracic echocardiography or multi-gated radionuclide angiography. Imaging strategies that detect cardiac injury before overt left ventricular systolic dysfunction provide an opportunity for early intervention and improved cardiac outcomes.