FRI0636 The value of persistence in treatment with subcutaneous tnf-alpha inhibitors for ankylosing spondylitis
Authors: M. Ivergård, J. Dalén, A. Svedbom, C. M. Black, R. H. Borse, S. Kachroo
Journal: Annals of the Rheumatic Diseases (2018)

<h3>Background:</h3> Subcutaneous Tumor Necrosis Factor-alpha inhibitors (SC-TNFi) with higher persistence are often perceived as being more costly compared with SC-TNFis with lower persistence based merely on the resulting higher drug acquisition cost. Thus, failing to consider possible health care cost offsets, productivity gains and increased quality of life. <h3>Objectives:</h3> The objective of this study was to assess the value of higher treatment persistence by evaluating cost-effectiveness of SC-TNFis for Ankylosing Spondylitis (AS), with higher persistence compared with lower persistence from a payer and societal perspective. <h3>Methods:</h3> A Markov cohort model, following the framework of the NICE commissioned York model in AS<sup>1</sup>, was developed. In the model, patients achieving BASDAI50 response at 12 weeks transition to treatment maintenance and non-responders to conventional care. In each cycle, patients are at risk of death. Patients discontinuing treatment after the treatment response period rebounds in BASDAI and BASFI by what was gained at response. Inputs were sourced from the York model where available and costs were updated to 2016/17 prices. The societal perspective included indirect costs from productivity losses (i.e. absenteeism, presenteeism, and early retirement)<sup>2</sup>. Two treatment strategies are investigated; SC-TNFis with constant annual withdrawal rates of 10% and 20%. Apart from discontinuation rates, treatment inputs are the same for the two strategies. <h3>Results:</h3> Better persistence increases the treatment cost, but this is partly offset by savings in disease related costs and from a societal perspective it is cost-saving (figure 1). In addition, the improvement in the health of persistent patients is noticeable as a gain in quality adjusted life years (QALYs). The ICERs of the 10 % and 20% withdrawal rate treatment strategies versus conventional care (CC) are £18,323 and £20,063, respectively (table 1). Given a WTP of £20.000 the strategy with better persistence compared to the strategy with worse persistence is clearly cost-effective (ICER= £16,112) and dominates when a societal perspective is taken. <h3>Conclusions:</h3> Persistence appears to be a driver of cost-effectiveness of SC-TNFi treatment in patients with AS, especially when a societal perspective is taken. Therefore, prescribing the SC-TNFi with the best persistence may be a cost-effective strategy. <h3>References</h3> 1. Corbett M, et al. Tumour necrosis factor-alpha inhibitors for ankylosing spondylitis and non-radiographic axial spondyloarthritis: a systematic review and economic evaluation. Health Technology Assessment(Winchester, England) 2016;20(9):1–334, v-vi. 2. Raffia R, et al. Healthcare costs and productivity losses directly attributable to ankylosing spondylitis. Clinical and Experimental Rheumatology2012;30:246–253. <h3>Disclosure of Interest:</h3> M. Ivergård Employee of: Mapi, J. Dalén Employee of: Mapi, A. Svedbom Employee of: Mapi, C. Black Shareholder of: Merck &amp; Co., Inc., Employee of: Merck &amp; Co., Inc., R. Borse Shareholder of: Merck &amp; Co., Inc., Employee of: Merck &amp; Co., Inc., S. Kachroo Shareholder of: Merck &amp; Co., Inc., Employee of: Merck &amp; Co., Inc.