Therapeutic Effects of Apremilast on Enthesitis and Dactylitis in Real Clinical Setting: An Italian Multicenter Study.

Enthesitis and dactylitis are difficult-to-treat features of psoriatic arthritis (PsA), leading to disability and affecting quality of life. The aim of this study is to evaluate enthesitis (using the Leed enthesitis index (LEI)) and dactylitis at 6 and 12 months in patients treated with apremilast. Patients affected by PsA from fifteen Italian rheumatological referral centers were screened. The inclusion criteria were: (a) enthesitis or dactylitisphenotype; (b) treatment with apremilast 30 mg bid. Clinical and treatment history, including PsA disease activity, were recorded. Mann-Whitney and chi-squared tests were used to assess the differences between independent groups, and Wilcoxon matched pairs signed-rank test assessed the differences between dependent samples. A The Eph cohort consisted of 118 patients (median LEI 3); the Dph cohort included 96 patients with a median dactylitis of 1 (IQR 1-2). According to an intention to treat analysis, 25% and 34% of patients with enthesitis achieved remission (i.e., LEI = 0) in T1 and T2. The remission of dactylitis was 47% in T1 and 44% in T2. The per protocol analysis (patients observed for at least 12 months) showed that both dactylitis and LEI significantly improved in T1 (median LEI 1 (IQR 1-3)) and T2 (median LEI 0 (IQR 1-2)). Eph and Dph PsA patients treated with apremilast experienced a significant improvement in enthesitis and dactylitis activity. After 1 year, enthesitis and dactylitis remission was achieved in more than one-third of patients.