Off-label use of rituximab for dermatologic conditions: A single center review

BackgroundRituximab (RTX) has been utilised off-label for a variety of dermatological indications beyond pemphigus vulgaris. Efficacy has been reported in other immunobullous disorders, inflammatory dermatoses and connective tissue diseases.ObjectivesTo assess the off-label use of RTX in our centre with respect to indications, frequency and duration of treatment, efficacy, and adverse events.MethodsCharts were retrospectively reviewed for all patients who received dermatologist-prescribed RTX infusions off-label at our centre between 2009 and 2022. Efficacy was categorised based on reported percentage reduction of disease activity: very good (75%-100%), good (50%-74%), partial (25%-49%) and none (0%-24%).ResultsTwenty-nine patients received RTX off-label during this time period. Infusions were discontinued in 28% (n = 8), due to insufficient clinical response. Median treatment duration for those on 6-12-monthly regular infusions was 2.4 years (range 0.5-11 years). Indications included cutaneous lupus (n = 9), mucous membrane pemphigoid (n = 5), pyoderma gangrenosum (n = 6), lichen planus (n = 2), dermatomyositis (n = 1), livedoid vasculitis (n = 1), sarcoidosis (n = 1), bullous pemphigoid (n = 1), pemphigus vulgaris, foliaceus and vegetans (n = 1 each). Clinical improvement was documented in 79% (n = 23); very good in 48% (n = 14), good in 17% (n = 5), and moderate in 14% (n = 4). Clinical efficacy in immunobullous disorders was 100% (9/9), 67% in cutaneous lupus (6/9), 33% in pyoderma gangrenosum (2/6), and 50% in lichen planus (1/2). No side effects were documented for 79% (n = 23). Adverse peri-infusion events were seen in three patients (10%). Four patients died during follow up; one due to neutropenic sepsis with a background of advanced malignancy, and three due to Covid-19. ConclusionsRTX was prescribed for multiple off-label dermatological indications, often for recalcitrant disease. Responses were good overall, with a reassuring safety profile. Three patients died of Covid-19; knowledge of the impact of RTX on the immune response and efficacy of vaccines is expanding and will continue to inform guidelines for RTX use in the post-Covid era.