Biological correlates of acute hypersensitivity events with DAB₃₈₉IL-2 (denileukin diftitox, ONTAK®) in cutaneous T-cell lymphoma: Decreased frequency and severity with steroid premedication

DAB₃₈₉IL-2 (denileukin diftitox, ONTAK®) is a cytokine-targeted fusion protein that delivers the catalytic domain of diphtheria toxin to lymphoma cells expressing the interleukin-2 receptor (IL-2R). In phase I and phase III studies of DAB₃₈₉IL-2 in patients with cutaneous T-cell lymphoma (CTCL), non-Hodgkin's lymphoma, and Hodgkin's disease in which premedications were limited to diphenhydramine and acetaminophen, acute infusion-related hypersensitivity reactions occurred in 70% of patients and vascular leak syndrome (VLS) in 27%, resulting in discontinuation of therapy in 29% of patients. There was no correlation between the dose or half-life of DAB₃₈₉IL-2 and the occurrence of hypersensitivity events or VLS. To explore whether steroid premedication would improve the tolerability of DAB₃₈₉IL-2, we treated 15 patients with CTCL with either dexamethasone or prednisone prior to each dose of DAB₃₈₉IL-2. The incidence of acute infusion events was significantly decreased, with only three patients experiencing acute infusion events (one grade 4) and only two patients developing clinically apparent VLS. Grade 3 skin rash occurred in two patients and moderately severe asthenia in nine patients. A significantly improved response rate of 60% was noted with the use of steroid premedication compared to prior studies in which steroids were prohibited. We conclude that steroid premedication significantly improves the tolerability of DAB₃₈₉IL-2 without compromising the clinical response.