Health economic analysis
Health economic analysis of bevacizumab+paclitaxel versus paclitaxel alone as first-line treatment for metastatic breast cancer
Structured summary
|Updated
The Norwegian Knowledge Centre for the Health Services has been commissioned by Norwegian Directorate of Health’s Cancer Programme to make an assessment of the cost per progression-free year gained associated with the use of bevacizumab in combination with paclitaxel versus paclitaxel alone, as first line treatment for metastatic breast cancer.
Key message
Background
The Norwegian Knowledge Centre for the Health Services has been commissioned by Norwegian Directorate of Health’s Cancer Programme to make an assessment of the cost per progression-free year gained associated with the use of bevacizumab in combination with paclitaxel versus paclitaxel alone, as first line treatment for metastatic breast cancer. The result is likely to have bearings on a possible revision of the treatment guidelines for breast cancer in Norway.
Methods
We developed a health economic model of the Markov type in which we compared data from a clinical study, Miller et al . 2007, with Norwegian cost data associated with the treatment alternatives.
Results
Mean progression-free time in the group treated with bevacizumab+paclitaxel was 1 1.2 years whereas it was 0.73 years in the comparator group. This resulted in an incremental effect of 0,47 progression-free years. With regard to quality of life, the incremental effect was 0.2 QALYs. We estimated the incremental costs associated with use of bevacizumab+paclitaxel from a health service perspective to be NOK 765 000, which translates into a cost per progression-free life year gained of NOK 1.6 million and a cost per QALY gained of NOK 3.8 million. The estimate from the societal perspective, where tax, value-added tax and social security payments were deducted, was approx. NOK 1.3 million per progression-free life-year and NOK 3 million per QALY gained.
Conclusion
The cost per progression-free year gained is relatively high, and the cost per QALY gained is higher than cost-effective thresholds which have been proposed in Norway.
Summary
Background
The Norwegian Knowledge Centre for the Health Services has been commissioned by the Norwegian Directorate of Health’s Cancer Programme to make an assessment of the cost per progression-free year gained associated with the use of bevacizumab in combination with paclitaxel versus paclitaxel alone, as first line treatment for metastatic breast cancer. The result is likely to have bearings on a possible revision of the treatment guidelines for breast cancer in Norway.
Breast cancer is the most common form of cancer among women. In 2007, 2761 new cases were registered in Norway. Death from breast cancer is linked to the development of metastases (stage IV). Metastatic breast cancer cannot be cured with the treatments currently available. In 2006, 679 women died due to breast cancer. Slightly more than 50% of the breast cancer cases occur in women between the ages of 45 and 64, while only 10% occur in women below the age of 45. Breast cancer is the leading cause for life years lost among women up to the age of 65. Five-year relative survival for patients with distant metastases at the time of diagnosis was 16.9% at the end of 2005.
The Norwegian national breast cancer guidelines refer to several alternative treatments for patients with metastatic breast cancer. The type and sequence of treatments for an individual patient is determined by treatment effect, toxicity and general state of health.
When cytostatic treatment is required, one starts with regimen containing anthracycline (most often administered in the combination treatments FAC or FEC) provided that more than 2 years have passed since anthracycline was given as adjuvant treatment. If such a regimen is not feasible, one selects a regimen containing taxanes (docetaxel or paclitaxel). In cases of HER2- positive breast cancer, treatment with taxanes is combined with trastuzumab. Other treatments may also be offered.
Angiogenesis (the formation of new blood vessels) is a prerequisite for the spreading process occurring in many types of cancer disease. The Vascular Endothelial Growth Factor (VEGF) acts as a key signal compound in the body in the formation of new blood vessels. Bevacizumab (Avastin) is a humanised antibody which binds to and neutralises VEGF, thereby influences the supply of blood to new cancer cells.
Methods
The objective of our health economic evaluation was to calculate the cost per progression-free life year gained associated with giving metastatic breast cancer patients bevacizumab+paclitaxel as first-line treatment rather than paclitaxel alone. We developed a so-called Markov model based on progression-free and overall survival data from the clinical trial Miller et al . from 2007 as well as Norwegian cost data. Miller et al do not state the treatment regimens which were employed subsequent to progression on either first-line treatments. We have therefore used costs linked to the relevant 2 nd and 3 rd line treatments for metastatic breast cancer in Norway. Quality of life data were, inspired by a recent Swiss study similar to our own, taken from a Canadian study on metastatic breast cancer patients from 1999.
We included costs associated with the purchase of drugs, drug preparation in the hospital pharmacy and nurse time related to with infusions. Costs associated with the treatment of adverse events were considered to be negligible. Our primary analysis was carried out from the perspective of the health services, but we have also chosen to present results from a societal perspective where value-added tax and other transfer payments to the government have been deducted from the costs. Costs linked to productivity loss were not included.
Results
Mean progression-free time in the group treated with bevacizumab+paclitaxel was 1 1.2 years whereas it was 0.73 years in the comparator group. This resulted in an incremental effect of 0,47 progression-free years. With regard to quality of life, the incremental effect was 0.2 QALYs. We estimated the incremental costs associated with use of bevacizumab+paclitaxel from a health service perspective to be NOK 762 000, which translates into a cost per progression-free life year gained of NOK 1.6 million and a cost per QALY gained of NOK 3.8 million. The estimate from the societal perspective, where tax, value-added tax and social security payments were deducted, was approx. NOK 1.3 million per progression-free life-year and NOK 3 million per QALY gained. We also calculated the effect of a co-financing scheme advanced by Roche, the company marketing bevacizumab in Norway, which resulted in a cost per progression-fee life year gained of approx. NOK 1,1 million from a health services perspective and NOK 850 000 from a societal perspective.
Discussion
A search for economic evaluations of bevacizumab for breast cancer with results that could be compared to our own resulted did not produce any results. We did however; identify a couple of other studies in which incremental costs have been assessed against changes in progression-free time. Even though the term progression-free life year intuitively suggests a year of life of a certain quality, it is not the same as a quality-adjusted life year (QALY). The former implies a weighting based on time, whereas the latter is a result of weighting based on quality. There is no clear-cut answer to the question of how to interpret the price of an extra progression-free year. If one were to apply a threshold, as is often done for QALYs, e.g. NOK 500 000 for sector over-arching programmes as discussed in a report from the Directorate of Health, bevacizumab+paclitaxel would not come across as cost-effective in comparison with paclitaxel alone as first-line treatment for metastatic breast cancer.
The limitations of our analysis comprise the fact that it is based on only one clinical trial, and then mainly on its survival curves. The model does not necessarily reflect Norwegian clinical practice in terms of the choice of comparator and the follow-up of individual patients. We were unable to access Norwegian data on progression-free time associated with first-line treatment for the patient group. Finally, the costs included are limited to those associated with the purchase and preparation of medicines, and nurse time related to infusion.
Conclusion
On the basis of our health economic model, which in turn is entirely based on effectiveness data from the clinical trial Miller et al. the cost per progression-free life year gained is very high, even when the co-financing scheme proposed by Roche has been accounted for. The cost per QALY is significantly higher than cost-effectiveness thresholds which have been proposed in Norway.
The Norwegian Knowledge Centre for the Health Services summarizes and disseminates evidence concerning the effect of treatments, methods, and interventions in health services, in addition to monitoring health service quality. Our goal is to support good decision making in order to provide patients in Norway with the best possible care. The Centre is organized under The Directorate for Health and Social Affairs, but is scientifically and professionally independent. The Centre has no authority to develop health policy or responsibility to implement policies.