Summary Background Drug survival rates reflect efficacy and safety and may be influenced by the availability of alternative treatment options. Little is known about time‐dependent drug survival in psoriasis and the effect of increasing numbers of biologic treatment options. Objectives To determine whether drug survival is influenced by the availability of treatment options and by factors such as gender, psoriatic arthritis or previous biologic treatment. Methods This observational, retrospective, multicentre cohort study analysed data from patients registered in the Austrian Psoriasis Registry (PsoRA) who were treated with biologics between 1 January 2015 and 30 November 2019. Results A total of 1572 patients who received 1848 treatment cycles were included in this analysis. The highest long‐term Psoriasis Area and Severity Index improvement was observed after treatment with ixekizumab, followed by ustekinumab and secukinumab, adalimumab and etanercept. Overall, ustekinumab surpassed all other biologics in drug survival up to 48 months. However, when adjusted for biologic naïvety, its superiority vanished and drug survival rates were similar for ixekizumab (91·6%), secukinumab (90·2%) and ustekinumab (92·8%), all of them superior to adalimumab (76·5%) and etanercept (71·9%) at 12 months and beyond. Besides biologic non‐naïvety (2·10, P < 0·001), the introduction of a new drug such as secukinumab or ixekizumab (relative hazard ratio 1·6, P = 0·001) and female gender (1·50, P = 0·019) increased the risk of treatment discontinuation overall, whereas psoriatic arthritis did not (1·12, P = 0·21). Conclusions The time‐dependent availability of drugs should be considered when analysing and comparing drug survival. Previous biologic exposure significantly influences drug survival. Women are more likely to stop treatment.

This retrospective multicentre analysis from the Psoriasis Registry Austria (PsoRA) was conducted to determine drug effectiveness and survival of anti-tumour necrosis factor alpha (anti-TNF-α) agents in patients with moderate-to-severe chronic plaque psoriasis over a 9-year period. Data on 1,019 treatment cycles with adalimumab (n = 460), etanercept (n = 501), and/or infliximab (n = 58) administered to 827 patients (272 women, 555 men) were available for analysis. Compared with etanercept, adalimumab and infliximab showed superior short-term effectiveness. Intention-to-treat-calculated median drug survivals for adalimumab (1,264 days) and etanercept (1,438 days) were similar to each other (p = 0.74), but significantly superior to that of infliximab (477 days) (p = 7.0e-07 vs. adalimumab and p=2.2e-07 vs. etanercept, respectively). Their drug survival rates at 36 months were 51.6%, 56.0%, and 22.6%, respectively. Survival rates correlated significantly with effectiveness for adalimumab and etanercept, but not for infliximab.

All available antipsoriatic therapies are of symptomatic character. Treatments established so far are limited in their use due to side effects or lack of efficacy resulting in poor quality of life for affected people. Development of new therapeutic approaches would not only broaden our armamentarium against psoriasis, but could also increase our understanding of the pathogenesis of this disease. In brief, 2 main targets represent attractive candidates, either the keratinocyte itself or the immune system. Promising therapeutic strategies include: (1) the search for new psoriasis susceptibility genes and their resulting phenotypes; (2) the interference with certain parts of cell signaling pathways that are involved in inflammatory processes; (3) the inhibition or elimination of activated T lymphocytes, e.g. by blocking of costimulatory signals or by deviation of a pathogenic immune response into a nonpathogenic one; (4) the blockade of proinflammatory cytokines; (5) the inhibition of leukocyte extravasation or trafficking; (6) the inhibition of angiogenesis. Some of these strategies are in phase 2 trials, others have already reached phase 3 status and are close to being approved by medicine agencies, and some are still visions of the future. This book chapter will give an overview of these new treatment strategies.