New Data Show That 'Arimidex'® (Anastrozole) Is A Cost-Effective Therapy Compared To Tamoxifen

Main Category: Breast Cancer
Also Included In: Cancer / Oncology
Article Date: 19 Jul 2007 - 1:00 PDT

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New data published this week in the British Journal of Cancer (BJC) confirms that 'Arimidex' (anastrozole) is a cost-effective treatment for early breast cancer, based on criteria established by the National Institute for Clinical Excellence (NICE) for commonly accepted cancer treatments. [1] NICE concluded in November 2006 that Arimidex is cost-effective when compared with tamoxifen and therefore recommended it as an option for the adjuvant treatment of early oestrogen-receptor-positive invasive breast cancer in postmenopausal women. [2] These latest findings, based on the most recent methodology guidelines from NICE, further corroborates NICE's recommendations and adds to the growing evidence that 'Arimidex' offers a cost-effective alternative to tamoxifen in these patients.2, [3]

The annual cost of hormonal drug therapy to the NHS is estimated at £64.6 million. [4] However, drug acquisition costs do not reflect the total financial burden of breast cancer. Disease recurrence also has an adverse impact, significantly increasing the overall cost of treatment - specifically, in terms of diagnosis, clinic appointments, inpatient and outpatient care, the need for additional surgery/chemotherapy/radiotherapy, adverse event management for extra procedures and follow-up investigations.4, [5]

Professor Robert Mansel, University of Wales College of Medicine, Cardiff, UK, commented, "Recurrence is the single most important factor which increases total cost of breast cancer therapy. Therefore, reducing recurrence would have the largest influence on breast cancer spending. This model demonstrates that by prescribing a more effective treatment that reduces the risk of recurrence compared to tamoxifen, you can potentially reduce the overall economic burden on the healthcare system of treating breast cancer in this setting."

Historically, tamoxifen has been regarded as an effective and inexpensive treatment option for hormone-sensitive early breast cancer. However, results from the Arimidex, Tamoxifen, Alone or in Combination (ATAC) Trial have led to the increasing use of anastrozole in the initial adjuvant setting. The study demonstrated that anastrozole, an aromatase inhibitor (AI), is superior to tamoxifen in terms of reduced risk of recurrence and improved tolerability. [6], [7] This most recent publication supports the use of anastrozole as a cost-effective alternative to tamoxifen.1

The cost-effectiveness analysis published this week was conducted to evaluate the economic consequences of choosing anastrozole over tamoxifen in terms of costs, QALYs gained and cost per QALY gained based on a model estimated over a 25-year period. The validated Markov model revealed that:

-- Anastrozole lead to a gain in 0.244 QALYs (or 0.231 life years) at an additional cost of £4,315 per patient1

-- The estimated incremental cost-effectiveness of anastrozole compared to tamoxifen was £17,656 (95% CI:£10,280 TO £39,235) per QALY gained*1

-- The incremental cost per life year gained was £18,702.*1

Professor Lesley Fallowfield, Psychosocial Oncologist, Cancer Research, UK commented, "Results from ATAC showed that anastrozole offers post-menopausal women with hormone-sensitive breast cancer a greater chance of preventing recurrence. We have now provided evidence that this effective, well-tolerated treatment is also cost-effective which should be reassuring to budget-holders (or primary care trusts), doctors and women alike."

Anastrozole has an annual acquisition cost of £894.25 and is the least expensive AI available [8] - costing 17% less than letrozole and exemestane. In comparison, the annual cost of trastuzumab (Herceptin) and taxanes, such as paclitaxel, are significantly higher.

Anastrozole remains the first and only AI that has been extensively assessed for safety and efficacy for over five years as initial adjuvant treatment in postmenopausal breast cancer patients.

*The acceptability curve for this analysis demonstrates a > 90% probability that the cost per QALY gained with 'Arimidex' would be lower than the £30,000 threshold established by NICE for commonly used cancer treatments.1

References:

[1] R Mansel et al on behalf of the ATAC Trialists' Group. Cost-effectiveness analysis of anastrozole vs tamoxifen in adjuvant therapy for early stage breast cancer in the United Kingdom: the 5-year completed analysis of ATAC ('Arimidex', Tamoxifen alone or in combination) trial. British Journal of Cancer (2007) 97: 152 - 161.

[2] NICE technology appraisal guidance 112 (Nov 1006)

[3] Hillner Be (2204) Benefit and projected cost-effectiveness of anastrozole versus tamoxifen as initial adjuvant therapy for patients with early-stage estrogen receptor-positive breast cancer. Cancer 101:1311 - 1322.

[4] Benedict A, Christie A (2003) Budget impact analysis of anastrozole as adjuvant therapy in the treatment of early breast cancer in the UK [abstract]. Value Health 6: 735.

[5] Lamerato L, Havstad S, Gandhi SK et al. Economic burden associated with breast cancer recurrence. Cancer 2006;106:1875-82

[6] ATAC Trialists' Group. Results of the ATAC (Arimidex, Tamoxifen, Alone or in Combination) trial after completion of 5 years' adjuvant treatment for breast cancer. Lancet. 2005; 365 (9453):60-62.

[7] J Cuzick et al. A detailed analysis of the benefits of anastrozole over tamoxifen for venous thromboembolic events (VTEs) after 5 years' treatment. Abstract 104. San Antonia Breast Cancer Symposium 2006.

[8] emims, accessed at http://www.emims.net July 2007.

Quality Adjusted Life Year

A year of life adjusted for its quality or its value. A year in perfect health is considered equal to 1.0 QALY. The value of a year in ill health would be discounted. For example, a year bedridden might have a value equal to 0.5 QALY. QALYs can therefore provide an indication of the benefits gained from a variety of medical procedures in terms of quality and life and survival for the patient.

NICE

NICE guidance is developed by a number of independent advisory groups made up of health professionals, those working in the NHS, patients, their carers and the public. The Board and senior management team set the Institute's strategic direction and oversee delivery, provide financial stewardship and ensure corporate governance.

Markov Model

Markov models assume that a patient is always in one of a finite number of discrete health states and all events are represented as transitions from one state to another. In this study, the Markov model was evaluated as a Monte Carlo simulation. The model projected outcomes over an actuarial horizon of 25 years.

http://www.arimidex.com