For patients with lymphoma who experience severe drug hypersensitivity reactions related to anti-CD20 immunotherapy, use of an alternative anti-CD20 antibody is a safe alternative or complementary approach to anti-CD20 desensitization, according to a study published as part of the 2020 ASCO Virtual Scientific Program.
Researchers used their pharmacology database to identify all patients followed at their institution who received rituximab and/or obinutuzumab, and/or ofatumumab and/or all patients who received a flat dose of less than 50 mL of the same drugs. Researchers identified all cases in which the anti-CD20 antibody was changed due to allergy, serum sickness, or other types of drug hypersensitivity reactions and all who received minimal doses of anti-CD20 in the context of a desensitization protocol. Drug hypersensitivity reactions were evaluated by an allergist or retrospective review following World Allergy Organization guidelines.
Among 343 patients receiving at least two different anti-CD20 antibodies or a flat dose of <50 mL, 44 patients experienced severe drug hypersensitivity reactions that required intervention. At the time of the reaction, 16 patients (36%) received the anti-CD20 as single agent, 24 (54%) in combination with chemotherapy, four (9%) in combination with ibrutinib or lenalidomide.
Among nine patients (20%), the reaction was defined as anaphylactoid (eight with rituximab, one with obinutuzumab), and in all eight patients receiving rituximab (18%), the reaction was defined as serum sickness. Episodes of drug hypersensitivity reactions were addressed with desensitization (n=29) or change of anti-CD20 agent (n=25); nine patients received both approaches, and one patient switched anti-CD20 antibodies twice. Overall, desensitization was successful in 21 patients (72.4%) and failed in eight patients. Change of anti-CD20 agent was successful in 23 patients (92%) and failed in two patients (P=0.09).