SAT0152 PREVALENCE AND SUCCESS OF ‘TRY AND SEE’ SUBCUTANEOUS BIOLOGIC DMARD DOSE REDUCTION IN ROUTINE CARE AND COST SAVING IMPLICATIONS
Authors: Jatin Mistry, Catherine Smith, Malama Sumbwanyambe, Margaret Sibley, Patrick Kiely
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background</h3> 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. <h3>Objectives</h3> 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. <h3>Methods</h3> 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. <h3>Results</h3> 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. <h3>Conclusion</h3> '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. <h3>References</h3> [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 <h3>Disclosure of Interests</h3> 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