SAT0152 PREVALENCE AND SUCCESS OF ‘TRY AND SEE’ SUBCUTANEOUS BIOLOGIC DMARD DOSE REDUCTION IN ROUTINE CARE AND COST SAVING IMPLICATIONS

Background Biologic disease modifying anti-rheumatic drugs (bDMARD) are widely used in rheumatologic practice. Subcutaneous bDMARDs are licenced in a fixed dose for all indications (RA, PsA, AS) yet therapeutic drug monitoring (TDM) of TNF inhibitors (TNFi) reveals a wide range of serum drug concentrations (1). EULAR recommendations (2) state that ‘one can consider tapering bDMARDs’ if a patient is in persistent remission (usually by lengthening the interval between subcutaneous injections), and in trials up to 80% sustain remission after tapering over 39 weeks (3). In routine care bDMARD dose reduction is usually initiated on a ‘try and see’ basis, in the absence of guidelines. Objectives To assess the prevalence and success of subcutaneous bDMARD dose reduction in routine care, per disease indication and bDMARD class, and the cost saving implications. Methods Dose interval information was collected prospectively in patients on subcutaneous bDMARDs with RA, PsA and AS attending for routine review at St George’s University Hospitals NHS Foundation Trust from October – November 2018. Department practice is that bDMARD dose reduction is discussed (but not mandated) with patients in sustained remission on a ‘try and see’ basis, without TDM. Results Data on 88 patients (female 46) were collected, RA 39, PsA 36, AS 13, mean age 50 years (range 24-78), TNFi n=75, other bDMARDs n=13. The dose interval was per licence in 79.5%, less frequent in 18% and more frequent in 2.5%. In those taking a bDMARD less frequently than per licence, the dose interval was increased by a mean 2.15 x licenced interval (range 1.14 – 6 x); in RA 1.88x, PsA 2.12x and AS 2.64x. Dose reduction had been attempted in 32%, but failed due to loss of efficacy in 43% of these (13.6% of entire cohort), including 50% with RA, 46% PsA and 20% AS. In those attempting a dose reduction, there was no difference in the% sustaining this for Etanercept 57% (8/14) and Adalimumab 50% (5/10) but lower for all TNFi (54%, 13/24) treated patients compared to other bDMARDs (75%, 3/4). Dose reduction had not been attempted at any stage in 66% (RA 72%, PsA 61%, AS 62%). Cost savings from 16 patients with sustained dose reduction over 3 years in this cohort were £97,653, extrapolated to 18% of the entire population (n∼1500) on subcutaneous bDMARDs at our Trust makes £1.65 million saving over 3 years. Conclusion ‘Try and see’ dose reduction of subcutaneous bDMARDs has been attempted in one third of patients in routine care, with more success in AS where 80% sustained a lower dose at a mean 2.64 x licenced interval, compared to 50% of RA and 54% PsA patients at 1.88 and 2.12 x licenced interval respectively. Guidelines, possibly based on TDM, are needed to optimise current practice which falls short of the success of dose reduction in clinical trials (3). Even with a ‘try and see’ approach failing in 43% of attempts, the cost savings are very substantial to the healthcare economy. References [1] Merel J l’Ami, et al. Ann Rheum Dis2018; 77: 484-7 [2] Smolen JS, et al. Ann Rheum Dis2017; 76: 960-77 [3] Emery P, et al. N Engl J Med2014; 371: 1781-92 Disclosure of Interests Jatin Mistry: None declared, Catherine Smith: None declared, Malama Sumbwanyambe: None declared, Margaret Sibley: None declared, Patrick KIELY Paid instructor for: Amgen, Gilead, BMS, Speakers bureau: Abbvie, BMS, UCB, Lilly, Pfizer