Objectives To evaluate the prevalence of serious infusion-related reactions after rituximab (RTX) in a large prospective registry of patients with rheumatoid arthritis.
Methods The Autoimmunity and Rituximab registry (AIR) is an independent registry promoted by the French Society of Rheumatology that included 1983 patients with rheumatoid arthritis treated with rituximab and followed-up prospectively for seven years. An infusion-related reaction (IRR) was defined as occurring during or in the 24 hours following an infusion.
Results Overall, 45 IRR resulted in RTX discontinuation [2.2% of all patients with RA, 0.4% of all infusions]. These serious IRR occurred after the first cycle in 17 patients, the second cycle in 18, the third cycle in 7, the fourth cycle in 2 patients and after the fifth cycle in 1 patient. Serious IRR mainly occurred after the first infusion of the cycle (71% of the 45 IRR vs 39% after the second infusion). 32 patients (73%) had allergic or anaphylactic manifestations such as a skin rash (18 patients), a throat irritation (8 patients), an anaphylaxis (3 patients), a bronchospasm (2 patients) or an angioedema (1 patient), 5 (11%) hypertension, 3 patients (7%) fever, 4 patients (8.5%) other symptoms and 1 missing data. Among the 30 patients who had a serious IRR after the second or subsequent infusions, 15 (50%) had previously had a milder IRR requiring a transient interruption or a reduction in the infusion flow. There was no fatal infusion-related reaction, and all infusion-related reactions resolved after discontinuation of RTX and symptomatic treatment.
Conclusions The real life frequency of IRR resulting in RTX discontinuation is similar to that observed in clinical studies, approximately 0.5 %. Allergic manifestations were the most frequent. These reactions mainly occurred during the first two cycles, but nearly a quarter of them occurred after the 3d or subsequent cycles. Last, severe reactions had been preceded by a milder infusion reaction to a former infusion in 50% of patients
Disclosure of Interest: None Declared