Comparative effectiveness research (CER) received a boost last year by the Patient Protection and Affordable Care Act as an approach that will help to identify best therapies and will also work to reduce costs by improving outcomes when best therapies are used.
CER is already having an impact on the direction of new research, reflecting attempts by healthcare stakeholders to reduce overall costs. With the ever-increasing number of generics entering the market, it is not surprising that the first-in-class generic approval by the US Food and Drug Administration (FDA) will become a research priority in the current environment of a cost- and outcomes-focused healthcare system.
On April 9, 2010, the FDA approved the first generic angiotensin receptor blocker (ARB)—losartan—for the treatment of hypertension and cardiovascular disease. It is therefore not surprising that comparative studies are now focusing on the efficacy and cost implications of losartan versus one of the branded ARBs. Several articles have already been published in 2011, and more are coming.
Readers of American Health & Drug Benefits fully understand that the drug acquisition cost does not reflect the overall cost of therapy. Other considerations, such as a lack of medication adherence, adverse events, and copayments, can skew the balance in favor of a branded agent, despite the reduced cost of the generic.
The most recent study comparing losartan and a branded ARB was published online on February 1, 2011.1 In this meta-analysis, Dr Anthony Gross and colleagues compared the efficacy and costs in previous studies of losartan and candesartan (which will be losing patent later this year) for hypertension and heart failure (HF).
In addition to efficacy, Dr Gross and colleagues evaluated the comparative incremental cost-effectiveness of these drugs within a UK National Health Service (NHS) setting. Their results showed slightly superior efficacy in diastolic (–1.96 mm Hg) and systolic (–2.40 mm Hg) blood pressure (BP) with candesartan. Using a Markov model to assess the cost difference based on the efficacy difference in BP showed that using the generic ARB would save the NHS approximately €200 million annually. No difference in efficacy was found for HF.
As tempting as this finding may be to come to conclusions, however, results from other studies complicate the picture. A new study comparing data from the Swedish Heart Failure Registry using the same agents for patients with HF shows an efficacy advantage for candesartan for HF, which also resulted in a lower mortality for patients using candesartan.2
Yet another new article conducted in the United States using another branded ARB, olmesartan (which will be losing patent in 2016), showed a significant difference in seated BP efficacy favoring the branded ARB, despite a similar adverse event profile.3
Clearly, more studies using real-world data in line with CER criteria are needed. The work is cut out for researchers and payers to develop mechanisms that will lead to greater coherence in interpreting clinical outcomes and cost comparisons. Considering the current state of economic affairs, the use of generics is likely to increase, and more accurate information will help payers to develop improved benefit designs to allow patients and the US system to reap the benefits of CER.
- Gross A, Bodalia PN, Macallister RJ, et al. Comparative clinical- and cost-effectiveness of candesartan and losartan in the management of hypertension and heart failure: a systemic review, meta- and cost-utility analysis. Int J Clin Pract. 2011 Feb 1 [Epub ahead of print]. http://www.news-medical.net/news/20110203/Genericdrugs- to-treat-hypertension-heart-failure-could-help-NHS-save-c2a3200- million.aspx?page=2.
- Eklind-Cervenka M, Benson L, Dahlstrom U, et al. Association of candesartan vs losartan with all-cause mortality in patients with heart failure. JAMA. 2011; 305:175-182.
- Weir MR, Punzi HA, Flack JM, et al. A randomized, double-blind, forced-titration study to compare olmesartan medoxomil versus losartan potassium in patients with stage 1 and 2 hypertension. Postgrad Med. 2011;123:80-87.