Anti-tumour necrosis factor alpha (TNF-alpha) therapy yields high response rates shortly after institution of therapy in patients with rheumatoid arthritis (RA), and on theoretical grounds large differences in the effective dose between patients can be expected. Together with the high costs, these differences warrant new approaches to the way patients are dosed.
We used the Disease Activity Score (DAS28), a composite disease activity index, to titrate the dose of anti-TNF-alpha (adalimumab, D2E7; Knoll) in 21 patients with low disease activity in an open extension study lasting 40 weeks. The dose of anti-TNF-alpha was reduced stepwise and dosing intervals were kept stable. Disease activity and flares were assessed using the DAS28. Patients who flared received the previous effective dose.
Dose reduction was accomplished in 15 patients. The total amount of anti-TNF-alpha given to the patients was reduced by 67%. At the end of the study the mean DAS28 had not changed and no patients dropped out because of persistent worsening of the RA.
Dose titration of anti-TNF-alpha treatment using the DAS28 is feasible and leads to overall dose reduction while maintaining clinical efficacy. This approach will save costs and possibly prevent long-term side-effects.