The effect of increasing the dose of hydroxychloroquine (HCQ) in patients with refractory cutaneous lupus erythematosus (CLE): An open-label prospective pilot study

Background: Up to 30% of patients with cutaneous lupus erythematosus (CLE) fail to respond to hydroxychloroquine (HCQ). Objectives: We sought to evaluate the efficacy of increased daily doses of HCQ on cutaneous response in refractory CLE. Methods: We conducted an open-label prospective study between 2010 and 2014. Patients with CLE and HCQ blood level less than or equal to 750 ng/mL were included. The daily dose of HCQ was increased to reach blood concentrations greater than 750 ng/mL. The primary end point was the number of responders defined by an improvement of CLE Disease Area and Severity Index score (4 points or 20% decrease) in patients with HCQ blood concentration greater than 750 ng/mL. Results: We included 34 patients (26 women; median age 45 [range 28-72] years). Two nonadherent patients were excluded. The median CLE Disease Area and Severity Index score before treatment was significantly improved after treatment (8 [range 2-30] vs 1.5 [range 0-30]), P<.001). The primary response criterion was reached in 26 (81%) of the 32 patients analyzed. A decrease in HCQ doses without further CLE flare (median follow-up 15.8 [range 3.06-77.4] months) was achieved in 15 of the 26 responders. Limitations: The main limitations of the study are its open-label design and the limited number of patients included. Conclusions: Increasing HCQ doses to reach blood concentrations greater than 750 ng/mL should be considered before addition of other treatments in refractory CLE.