Clinical Trials in Nail Psoriasis: Cross-Sectional Analysis of the Current State of Research.

Introduction: Nail involvement occurs in approximately 90% of patients with cutaneous psoriasis and in isolation in 5%-10% of patients. There is an unmet need for diagnostic and therapeutic algorithms for nail psoriasis (NP), partially due to limited number of clinical trials. Methods: The ClinicalTrials.gov, the EU, the Australian New Zealand, and the World Health Organization International Clinical Trials Registries were queried for the term "nail psoriasis". Trial data characteristics were collected and analyzed. Results: A total of 112 clinical trials were included, with mean trial length 46.7 weeks and mean number of participants 272.7. Medications were most often studied in 97 (86.6%) trials, followed by lasers in 7 (6.3%) trials. NP Severity Index score was the most often studied outcome measure in 91 (84.3%) trials, and only 56 (52.8%) trials assessed adverse events. Only 3 (2.83%) trials included children, and many clinical trials excluded patients aged 65+ and 85+. Results were posted for 46 (41.4%) trials with mean participant age 45.1 years, mean percentage of females of 38.3%, and 87.8% of participants being White. Conclusion: Our findings highlight a need for clinical trials assessing efficacy and long-term therapeutic safety with a broad range of age-groups and increased representation of minorities and female patients.