1. 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: /bjd.17151

2. Lead Investigator: Evangelos J. Giamarellos-Bourboulis

3. 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

4. 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

5. 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)

6. 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.

7. 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

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

9. 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

10. Containment of exacerbations in relation to Hurley stage

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

12. 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.