Abstract
BACKGROUND: Cold urticaria (ColdU) is characterized by pruritic wheals following exposure of the skin to cold. Many patients show insufficient response to antihistamines, the first line treatment. Based on the high efficacy of interleukin-1(IL-1)-inhibition in cold-induced urticarial autoinflammatory diseases, we assessed the effects of rilonacept, an IL-1 inhibitor, in ColdU patients unresponsive to standard treatment. METHODS: In this randomized, double-blind, placebo-controlled two-center study, we included 20 patients with ColdU. In the first part, patients received 320 mg rilonacept or placebo (1:1) followed by weekly doses of 160 mg rilonacept or placebo for 6 weeks. In the second part, all patients received weekly 160 mg or 320 mg rilonacept for 6 weeks, open-label. The primary endpoint was change in critical temperature threshold (CTT). Secondary endpoints included changes in quality of life impairment (Dermatology Life Quality Index, DLQI), differences of inflammatory mediators upon cold provocation and safety assessment over the study period. RESULTS: Baseline mean CTTs were 20.2°C (placebo) and 17.3°C (rilonacept). Mean CTTs did not change significantly during the 6-week double-blind treatment (placebo - 0.45°C; rilonacept +0.89°C). IL-6, IL-18 and HSP-70 blood levels showed interindividual variability without significant changes during hand cold water bath provocation in placebo- or rilonacept-treated patients. In contrast, DLQI significantly improved in the rilonacept (mean DLQI reduction of 3.8; p = 0.002) but not in the placebo group (mean DLQI reduction of 0). Comparing baseline with the rilonacept open-label treatment, there were no changes in CTTs or DLQI scores. CONCLUSION: IL-1 inhibition with rilonacept did not improve ColdU, but demonstrated a good safety profile. CLINICAL TRIAL REGISTRATION: EudraCT number: 2012-005726-30. CLINICALTRIALS: gov identifier: NCT02171416.