Background Biologic therapies represent a significant advance in the treatment of plaque psoriasis. However, these therapies come at a high cost, making evaluation and comparison of each therapies’ cost-effectiveness crucial to ensure effective allocation of resources.

Purpose To evaluate the cost-effectiveness of biologic therapies in plaque psoriasis by taking real-world evidence (RWE) on discontinuation and dose adjustment into account in Spain. In addition, the study looked to assess the impact of different levels of discounts on cost-effectiveness.

Material and methods A model was developed which incorporated the probability of treatment discontinuation and dose adjustment with brodalumab, ixekizumab, secukinumab, ustekinumab, adalimumab, etanercept and infliximab over 2 years. The probability of discontinuation and dose adjustment in each case was calculated every 4 weeks based on a literature review of RWE. For brodalumab and ixekizumab, a discontinuation rate of 1% per 4 weeks was assumed in the base case as no RWE is currently available. The effectiveness of each treatment was based on a network meta-analysis. Only direct costs of therapy were considered (list prices). Sensitivity analyses was conducted with different levels of discounts. Cost-effectiveness was assessed as the cost per patient with complete clearance (PASI 100).

Results The modern anti-IL-17 biologic therapies were highly cost-effective compared to the anti-TNFs and anti-IL-12/23. In the base case analysis, the average cost per PASI 100 responder was highest for etanercept at €526,800, followed by ustekinumab (€154,170), adalimumab (€137,511), infliximab (€125,467), secukinumab (€88,100), ixekizumab (€68,467) and brodalumab (€62,165), respectively. Sensitivity analyses indicated that discounts of approximately 80% for etanercept, 40% for ustekinumab, 35% for adalimumab and 30% for infliximab, respectively, were necessary in order to achieve similar levels of cost-effectiveness as secukinumab, whereas discounts as high as 90% for etanercept, 60% for ustekinumab, 55% for adalimumab and 50% for infliximab were necessary to reach similar levels of cost-effectiveness as ixekizumab and brodalumab.

Conclusion According to this economic model, modern anti-IL-17s are highly cost-effective compared to anti-TNFs and anti-IL-12/23. Though discounts may be a way of making anti-TNFs and anti-IL-12/23 more cost-effective, this study indicates that very high levels of discounts would be necessary to achieve this.

References and/or acknowledgements None.

Conflict of interest Corporate-sponsored research or other substantive relationships: employee at LEO Pharma.