Background The anti-TNFα drugs Adalimumab (ADA) and Etanercept (ETA) are given in standard doses and intervals. Many patients on these drugs achieve long-term remission or low disease activity yet continue on the standard doses. Departmental costs have escalated as increasing numbers of patients are treated.
Objectives 1) Determine whether patients in long-term remission or low disease activity can reduce their dose or frequency of administration without disease flare. 2) Assess cost savings by alterations in dose or frequency of administration
Methods Patients (>17 years old) with Inflammatory Arthritis, who were receiving either ADA or ETA by self-administered subcutaneous injection, were asked to reduce the dose or frequency of administration of their drug. Patients were selected if they had persistent DAS28 ≤3.1. The following doses were commenced (numbers of patients): ETA: 50mg every 10 days (15), 50mg every 2 weeks (43), 25mg weekly (5). ADA: 40mg every 3 weeks (18), 40mg every 4 weeks (14). Patients reverted to their previous dosing schedule if they had a disease flare or perceived reduction in quality of life. Costs for subcutaneous anti-TNFα therapy at end of November 2010 were compared with end of November 2011.
Results Overall, 86 patients changed their dosage, of which 72 have continued on reduced dose or frequency of administration for an average of 7 months (range 1 – 33 months, median 6 months). Twenty-two patients so far have changed dose for 9 months or more. Of the 14 patients who reverted to full dose, mean duration of reduced frequency of administration in this group was 3.6 months (range 0.5 – 9 months, median 3 months).
Those who are successful in reducing their dose or frequency of administration are more likely to be lifelong non-smokers (46%) than those who have to restart their previous doses (21%). Those who fail usually do so within a few months. Botsios et al (1) have shown that patients succeeding on reduced dose are more likely to have shorter duration of disease but there is no data on the effect of smoking. Our data suggest that dose reduction could be targeted to patients who are lifelong non-smokers.
Conclusions 1) Patients in remission or low disease activity are willing to try reducing their dose or frequency of administration of subcutaneous anti-TNFα injections 2) Patients are more likely to remain on reduced dose if they are lifelong non-smokers. 3) Considerable cost savings can be made by tailoring treatment in this way
 Botsios C, Furlan A., Ostuni P et al. Effects of low-dose etanercept in maintaining DAS-remission previously achieved with standard dose in patients with rheumatoid arthritis. Ann Rheum Dis. 2009;66:54
Disclosure of Interest None Declared