Northeastern Ohio Universities College of Medicine, Youngstown, OH, USA. E-mail: bmr{at}neoucom.edu
SIR, There is no question that tumour necrosis factor inhibitors have made a major difference in our ability to control rheumatoid arthritis. Claims [14] related to cost-effectiveness of one such inhibitor, infliximab (Remicade), must be more closely examined.
It is bothersome to find allegations that one can demonstrate lifetime cost-effectiveness based on limitation of use to only 1 or 2 yr of therapy [14] with a medication whose benefits disappear to baseline with its cessation [5, 6]. Kobelt et al.'s [1] recent article must be reconciled with their 2001 American College of Rheumatology meeting presentation [2]. They reported US$6600 extra cost offset the direct costs of methotrexate therapy by $1190, suggesting a cost per quality of life gain of $29 900. This study was very difficult to assess, as multiple clinical trials were combined and their listed direct product cost was less than half that in clinical practice in both the UK and the USA. They reported a cost-effectiveness ratio of $38 200 per discounted quality-adjusted life year (QALY). However, this (similar to the present study) was predicated on the use of infliximab for no more than 2 yr! Their more recent study is similarly difficult to interpret, as it uses historical controls of individuals with early rheumatoid arthritis (different catchment group from infliximab group) from a disparate time period (515 yr prior). The assumption that treatment approaches were the same for the historical and infliximab groups makes the unwarranted assumption of absence of progress in rheumatological care approaches over that time period.
These analyses [14] appear to represent biased secondary analyses of clinical trials, as opposed to real-world usage experience and do not seem to factor in toxicity issues [710]. Maksymowych et al. [8] reported adverse events in 32.6% (11.6% infectious, 4.2% gastrointestinal, 3.2% haematological) after a mean of only 4.2 infusions in 95 patients. Adverse events were considered severe in 11.6%. Safety is especially of concern in view of the report of cancer in 1 of 17 patients by Shergy et al. [9] and in 1 of 32 patients by Yazici et al. [10] within 1 yr of therapy initiation.
Therapies targeting tumour necrosis factor are clearly effective in treatment of rheumatoid arthritis [5, 6]. Data on relative safety and expense of currently available etanercept (Enbrel) and infliximab (Remicade) would seem to favour etanercept [11] were it not for the insurance reimbursement fluke (at least in the USA): payment in the USA is generally available for infusion of infliximab, while use of etanercept is economically limited to only those patients with full prescription coverage or who have sufficient disposable income to afford the $10 000-plus per year expense. I look forward to application of Kobelt et al.'s [1] methodology to calculation of the true cost-effectiveness of medications (including toxicity), use of which is likely to be required for decades.
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