COST-SAVINGS OF ADALIMUMAB IN HIDRADENITIS SUPPURATIVA: A RETROSPECTIVE ANALYSIS OF A REAL-WORLD COHORT Maria Argyropoulou, Theodora Kanni, Miltiades Kyprianou, Nikolaos Melachroinopoulos, Evangelos J. Giamarellos-Bourboulis 4th Department of Internal Medicine, National and Kapodistrian University of Athens, Greece British Journal of Dermatology. DOI: 10.111/bjd.17151

Lead Investigator: Evangelos J. Giamarellos-Bourboulis

What’s already known? A cost-savings analysis has never been published after the registration of adalimumab for HS It is anticipated that the cost of management of exacerbations of hidradenitis suppurativa (HS) is substantial

The modulation of exacerbations of HS by anti-TNFs Objective To investigate: 1 The modulation of exacerbations of HS by anti-TNFs How the cost of HS may be changed by adalimumab in a real-life setting. 2

Available Registry: September 2003-October 2016 Selection of patients for inclusion in the analysis Secondary study endpoint Primary study endpoint Cost savings under anti-TNFs expressed as the cost-savings per patient visit and as the impact of anti-TNFs on the annual cost. 1 Diagnosis of HS as defined by the 2009 definition 2 Hurley II and III stage lesions Containment of HS exacerbations with the use of anti-TNFs in relation to Hurley HS stage in a real world setting. 3 At least one year of follow-up 4 At least three visits per year Assumption: the activity of adalimumab equals infliximab and etanercept (available patients in the database under different anti-TNFs)

Available Registry: September 2003-December 2016 First analysis approach 02 Second analysis approach Cost-savings by anti-TNFs using patient-visits. Cost savings were calculated by the difference between the cost of patient visits under anti-TNFs and the cost of patient visits under other treatment. The prescription cost of adalimumab was used as an index of the prescription cost of anti-TNFs. Total cost of each patient during the entire years of follow-up was calculated separately for their life years. This was subjected to 2-way analysis of variance as the dependent variable with Hurley stage (III vs II) and treatment (anti-TNFs vs other treatments) and their interaction as the independent effects.

Containment of Exacerbations A patient should meet ALL the following in each visit: Positive HS clinical response (HiSCR) score assessed retrospectively; 04 No need for hospitalization 03 No need for antibiotic prescription or for change of antibiotics if the patient was already on antibiotics. 02 No HS flare-up 01

Elements of total containment of exacerbations under Anti-TNFs and under other treatments CI: confidence interval OR: odds ratio

Cost per patient-visit Anti-TNFs Other treatments Number of patient-visits 865 346 Hospitalizations (number of in-patient treatments) 20 80 Number of out-patient treatments 297 179 Total cost of anti-TNF prescriptions (€) 300,535.60 - Total cost of hospitalizations (€) 46,746.00 186,984.00 Total cost of out-patient treatments (€) 68,250.60 41,134.20 Total cost (€) 402,003.60 228,118.20 Cost per patient visit (€) 480.38 659.30

Containment of exacerbations in relation to Hurley stage

Analysis of variance of factors affecting per year/patient cost comparisons between subgroups

Conclusions Treatment with anti-TNFs achieves significant cost-benefit through containment of HS exacerbations. The efficacy of anti-TNFs was similar for patients at Hurley II and at Hurley III stages.