Drug survival of biologic therapies for palmoplantar pustulosis: A nationwide study

Background Biological therapies have established efficacy in psoriasis vulgaris. However, palmoplantar pustulosis (PPP) has proven difficult to treat, and data on drug survival in these patients remain scarce. Objective To investigate drug survival of biological treatments in a nationwide cohort of patients with PPP. Methods We included all patients treated for PPP with a biologic from a prospective Danish nationwide registry between 2007 and 2019. Descriptive statistics were reported. Drug survival was calculated for all patients and specified for the most frequently used biologics. Drug survival was reported as median time to discontinuation. Kaplan–Meier plots were used to visualize drug survival. Trajectories of Dermatology Life Quality Index (DLQI) scores were plotted by interpolating between the different visits with a dermatologist for each treatment course. Results We identified 85 individual patients who received biological therapy for PPP across 194 treatment courses during follow‐up. Of the included treatment courses, 151 (77.8%) were discontinued. The most frequent cause of discontinuation was ineffective response to treatment (54.3%), while 18.5% of courses were discontinued due to adverse events. The median drug survival across all therapies for PPP was 9.3 (Inter quartile range (IQR), 3.9–25.6) months. Ustekinumab demonstrated the longest median time to discontinuation of 14.6 (IQR, 9.1–51.8) months. The proportion of bio‐naive patients in treatment at 12 months were according to drug 47.9% for adalimumab, 64.3% for ustekinumab and 40.0% for secukinumab. For bio‐experienced, it was 58.2% adalimumab, 54.5% for ustekinumab and 51.4% for secukinumab. Conclusions The treatment of PPP poses significant challenges, with limited drug survival observed across all therapies regardless of prior experience with biologics. Ustekinumab demonstrated the longest median drug survival. Notably, patients discontinuing therapy due to inefficacy exhibited higher DLQI scores, highlighting the importance of personalized treatment selection and timely consideration of therapy changes when inefficacy is established.