How to manage hypersensitivity reactions to biological agents?

Biological agents induce cutaneous adverse drug reactions (CADR) different from those observed with xenobiotics. Type alpha is the cytokine release syndrome, type beta are hypersensitivity reactions and type gamma is a cytokine imbalance syndrome. Infusion-reactions, anaphylactoid reactions occur with various biological agents administered intravenously. In non-severe cases the infusion rate has to be reduced, in severe reactions, the treatment must be stopped and resuscitation carried out with corticosteroids and epinephrine. Reactions may be due to an alpha syndrome but a true allergy could be involved as demonstrated in some patients with IgE antibodies to the galactose-alpha-1,3-galactose portion of the cetuximab or anti infliximab-IgE. Some desensitisation protocols have been published. Non allergic itching and eczema-like lesions are frequent with epidermal growth factor receptor inhibitors. Rash or desquamation was observed in 40% of cases with antiangiogenic agents, 90% of patients treated with imatinib have rashes, oedema or pruritus and a non-allergic periorbital oedema. Severe CADR, such as Stevens-Johnson syndrome, can be provoked. Delayed readings of intradermal tests could be of value in managing patients with a maculopapular rash due to interferon. Anaphylaxis attributed to omalizumab seems to be rare (0.2%) and skin rashes occur in 7% of cases. Anaphylactoid reactions occur in 1% of patients treated with natalizumab. In the case of anti-natalizumab antibody-mediated reactions, treatment should be stopped. These allergic-like side effects of new biological agents must be known and reported to Pharmacovigilance agency networks.