Successful rapid desensitization to atezolizumab in delayed hypersensitivity confirmed with lymphocyte transformation test

Clinical Implications This is the first case of type IV hypersensitivity reaction to atezolizumab confirmed with positive drug provocation and a lymphocyte transformation test. After the second cycle, a computed tomography scan showed partial response of liver metastases. Because of the good response of the patient to atezolizumab, the medical oncologist (MO) decided to continue the same drug and the patient was referred to our allergy department. Total dose 1,200 mg Solution concentration, mg/mL Total dose in each solution, mg Drug Solution A 250 mL 0.096 24 Atezolizumab Solution B 250 mL 0.96 240 Atezolizumab Solution C 250 mL 4.06 1,015 Atezolizumab Table I Ramon y Cajal University Hospital standard rapid desensitization protocol adapted for total dose of 1,200 mg atezolizumab diluted in 250-mL volume of 0.9% saline solution