Drug survival of biologics and non-biologics in patients affected by palmoplantar psoriasis: a “real-world”, mono-center experience

Background: Data on the treatment of palmoplantar psoriasis (PP) are very limited as these patients are often excluded from clinical trials. Moreover, this form of psoriasis is often resistant to treatment, making its clinical management complex. Methods: Primary endpoint was to evaluate the clinical and demographic characteristics and the drug survival of both biological and non-biological drugs in a population affected by PP. Secondary endpoint was to highlight any differences between the hyperkeratotic and pustular variant. We analyzed data from 233 psoriasis patients with palmoplantar involvement, with or without chronic plaque psoriasis. We performed a drug-survival analysis with the aid of Kaplan-Meier survival and a multivariate analysis to highlight the influence of certain variables on treatment persistence using a Cox regression model. Results: The drug-survival analysis revealed that biologic drugs compared to non-biologic drugs are associated with a higher persistence in treatment (59.73 vs. 43.56%); in particular, anti-IL23 drugs were found to be the drugs with the best drug-survival overall (67.94% of patients at 60 months are still on these drugs). Furthermore, our multivariate analysis shows that when compared with biological drugs, non-biological drugs are associated with an increased risk of treatment discontinuation (HR = 1.95 [95% CI: 1.41-2.68], P = 0.001). Conclusions: Our study confirms the difficulty of treating PP and shows that biologic drugs are associated with longer persistence in treatment than non-biologics in both PP's variants, not because of their higher effectiveness but because of their better safety profile.