OP0196-HPR Dose Reduction of Biologic Drugs in Axial Spondyloarthritis in Clinical Practice

BackgroundThe practice of reducing the dose of anti-TNF agents during the treatment of patients with axial spondyloarthritis (axSpA) is often applied in clinical practice; it is not unusual for patients with axSpA to reduce the dose of anti-TNF agents despite the lack of supporting evidence from clinical trials or real-world investigations. Reasons for dose reduction include patient preference (fewer injections or infusions when the patient feels well) and cost reduction. The 2010 update of the ASAS recommendations for the use of anti-TNF agents in patients with axSpA does not consider dose reduction, nor do the 2015 draft BSR guidelines on the topic of biologics in axSpA. However, limited studies have indicated positive results.1–3 Real-life data regarding dose reduction are therefore valuable and may inform further studies, potentially enabling a rational approach to dosing in clinical practice to be adopted in the future.ObjectivesTo report the results of anti-TNF dose reduction in axSpA patients attending rheumatology practices in the UK.MethodsIn this retrospective study in SpA clinics at two UK hospitals, patients with axSpA who met NICE response criteria after 12 weeks of anti-TNF treatment,4 and remained stable for at least 6 months, were considered for dose reduction. Dose reduction could have been suggested by either patient or practitioner. Dose reduction decisions were made on an individual basis and implemented by extending the interval between anti-TNF administration, reducing the dose of each administration, or both. Dose reduction was calculated as a percentage of the standard recommended dose. Outcomes reported include BASDAI, BASFI and BASMI. Observed case data are reported.Results47 patients had their dose reduced between June 2005 and December 2015 (25 adalimumab, 14 etanercept, 7 infliximab and 1 golimumab). Most patients (79%) were male and the mean age was 50.2 years (SD±10.5). At the time of anti-TNF initiation, mean BASDAI was 6.4 (SD±1.7), which improved to a mean of 1.8 (SD±1.4) at the time of dose reduction. BASFI and BASMI scores also improved from anti-TNF initiation to time of dose reduction (Table). The mean time interval between initiation of anti-TNF therapy and dose reduction was 3.8 years (SD±2.8).At the time of analysis 39/47 (83%) remained on a reduced dose and were stable, with maintained efficacy up to 24 months post dose-reduction (Table). In these patients, the mean dose reduction was 36% (SD±16). 8 patients (17%)