RESEARCH - TNF-alpha blockers are equally effective for treatment of RA

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Anti-TNF Drugs Equivalent for Treatment of Rheumatoid Arthritis

NEW YORK (Reuters Health) Apr 30 - Tumor necrosis factor (TNF)-alpha

blockers are equally effective for treatment of rheumatoid arthritis

(RA), results of a meta-analysis indicate.

Although the three drugs -- infliximab (Remicade), etanercept

(Enbrel), and adalimumab (Humira) -- were approved by the US Food and

Drug Administration for treatment of RA between 1998 and 2003, there

are no published " head-to-head " comparative studies, Spanish

researchers point out in the April 17 issue of BMC Musculoskeletal

Disorders.

Led by Dr. Alberto Alonso-Ruiz at Cruces Hospital in Barakaldo, the

research team conducted a meta-analysis of 13 randomized trials

lasting at least 6 months that involved 7087 patients. Control

treatments were either methotrexate (MTX) or placebo.

In the combined analysis, anti-TNF drugs were significantly more

effective than control treatment, with no one agent emerging as

superior to the others. The number needed to treat to achieve an

American College of Rheumatology (ACR) 20 response was five.

" The main factor influencing therapeutic efficacy is the prior

response to disease-modifying anti-rheumatic drug treatment, " the

researchers state.

The benefits were most notable among patients with previously

inadequate responses to MTX when any of the three anti-TNF drugs was

added to their treatment regimens.

However, when an anti-TNF drug plus MTX was compared with MTX alone in

patients with no resistance to MTX, the relative efficacy of combined

treatment was low. Moreover, the benefits of etanercept or adalimumab

monotherapy were equivalent to those obtained using MTX alone for the

first time.

" Therefore, " Dr. Alonso-Ruiz and his associates state, " we advise

against starting treatment with anti-TNF-alpha drugs until a lack of

adequate response to MTX is clearly documented. "

Overall, adverse effect profiles showed that the number needed to harm

was 27. The biologic agents were associated with more adverse events

than controls (p = 0.021), particularly infliximab, which had a higher

frequency of serious adverse events (p = 0.048) and infections (p =

0.004). Withdrawal rates due to adverse events were higher for

infliximab and adalimumab, for which higher-than-recommended doses

were used, than for etanercept, for which recommended doses were not

exceeded.

" It might be potentially useful to start the indicated treatment with

a low dose and then increase it as a function of the magnitude of the

response, " the authors suggest. An alternative option to minimize

adverse effects might be to start with the recommended dose, then

tapering the dose after a significant stable effect is reached.

Still, the authors conclude, " more research is warranted, especially

well-powered head-to-head randomized comparisons of anti-TNF-alpha

drugs. "

BMC Musculoskelet Disord 2008;9.

http://www.medscape.com/viewarticle/573786

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Not an MD