Background With multiple biologic agents available for psoriasis treatment and a 20% rate of biologic therapy failure within 2 years due to loss of efficacy or side effects, research on the best treatment order has become particularly relevant.

Purpose The aim of this study was to assess how firstline anti-TNFα (etanercept or adalimumab) therapy affects ustekinumab cost per responder in patients with moderate–severe psoriasis.

Material and methods A single centre, retrospective, observational, comparative study was conducted over 16 months (November 2011 to March 2013). Patients were those who had been unsuccessfully treated with adalimumab or etanercept and were then treated with ustekinumab. The costs of ustekinumab and etanercept were determined from the recommended dosing schedule, extracted from public data and presented in 2016. The primary endpoint compared the cost per responder in each group.

Effectiveness of the treatment was defined as the percentage of patients in each treatment group who achieved ≥75% improvement from baseline PASI score (PASI75) at week 16; thus to calculate the cost per responder at week 16, the total cost of treatment in each group for 16 weeks was divided by the PASI75 response rates. Indirect costs were not included.

Results 33 patients were included in the study: 17 (51.5%) patients received as firstline treatment etanercept and 16 (48.5%) received adalimumab. Median age in the etanercept group was 46.6 years and 51.4 years in the adalimumab group (p=0.276). 41.1% and 50% of patients in the etanercept and adalimumab groups were men, respectively. At week 16 of ustekinumab treatment, 76.5% (13/17) of patients who had received etanercept as firstline treatment achieved PASI75 vs 50% (8/16) in adalimumab firstline treated patients (p=0.423). Thus at week 12, cost per responder was €9965 for firstline etanercept treated patients and €15 247 for adalimumab treated patients, an increase of €5282 per responder.

Conclusion Our results show that firstline anti-TNFα (adalimumab and etanercept) treatment in moderate–severe psoriasis does not affect ustekinumab effectiveness (p=0.43). So the most cost effectiveness treatment sequence is etarnecept—ustekinumab. This type of study, which analyses results in a real context setting, may contribute to optimising health resources. Future studies with a higher number of patients will assess the best cost effectiveness sequence in biologic treatment of moderate–severe psoriasis.

No conflict of interest