Desensitisation overcomes rituximab- and tocilizumab-related immediate hypersensitivity in childhood

Biologic drugs (BD) have been game-changers in rheumatic diseases; however, severe hypersensitivity reactions concerning anaphylaxis may limit their use. Desensitisation is a crucial option that is safe and effective to maintain patients on the preferred drug. Herein we report 84 Rapid Drug Desensitisation (RDD) procedures with rituximab and tocilizumab in children with rheumatic diseases.

The study was conducted as a retrospective chart review of patients who received tocilizumab or rituximab therapy between January 2010 and December 2018. The results of RDD with tocilizumab and rituximab were documented.

The study group consisted of 53 patients (11.6±4.5 years, 67.9% female) with rheumatic disease who had used tocilizumab (64.1%, 1007 infusions) or rituximab (35.8%, 73 infusions). Five patients (14.7%) had experienced anaphylaxis with tocilizumab and two patients (10.5%) with rituximab. Anaphylaxis was grade II in four cases whereas it was grade III in the remaining three children. Skin testing with the culprit BD performed in five children yielded positive results. We performed 65 RDDs with tocilizumab in 3 patients and 19 RDDs with rituximab in two patients. No reactions were recorded in 97.6% of the procedures. We observed one anaphylaxis during the 5th RDD of tocilizumab. After modifying the protocol, this patient continued tocilizumab RDD uneventfully.

RDD is a groundbreaking innovation which ensures giving the full target doses while protecting the patient against severe hypersensitivity reactions (HSRs) and anaphylaxis. As BD use increases in childhood, management of HSRs to BD will become more complicated, necessitating an increased need for RDD in clinical practice.