Efficacy and Safety of Gemtuzumab Ozogamicin in Patients With CD33-Positive Acute Myeloid Leukemia in First Relapse

TLDR

The study evaluated the efficacy and safety of single‑agent Mylotarg in patients with CD33‑positive AML in first relapse. 142 patients with AML in first relapse, median age 61, received two 2‑hour IV infusions of Mylotarg at 9 mg/m² every two weeks and were assessed for remission, survival, and adverse events. Thirty percent of patients achieved remission, and Mylotarg was associated with a favorable safety profile, with low rates of severe nausea, cardiotoxicity, and other serious adverse events, though myelosuppression and hyperbilirubinemia were common.

Abstract

PURPOSE: Three open-label, multicenter trials were conducted to evaluate the efficacy and safety of single-agent Mylotarg (gemtuzumab ozogamicin; CMA-676; Wyeth Laboratories, Philadelphia, PA), an antibody-targeted chemotherapy agent, in patients with CD33-positive acute myeloid leukemia (AML) in untreated first relapse. PATIENTS AND METHODS: The study population comprised 142 patients with AML in first relapse with no history of an antecedent hematologic disorder and a median age of 61 years. All patients received Mylotarg as a 2-hour intravenous infusion, at a dose of 9 mg/m 2 , at 2-week intervals for two doses. Patients were evaluated for remission, survival, and treatment-emergent adverse events. RESULTS: Thirty percent of patients treated with Mylotarg obtained remission as characterized by 5% or less blasts in the marrow, recovery of neutrophils to at least 1,500/μL, and RBC and platelet transfusion independence. Although patients treated with Mylotarg had relatively high incidences of myelosuppression, grade 3 or 4 hyperbilirubinemia (23%), and elevated hepatic transaminase levels (17%), the incidences of grade 3 or 4 mucositis (4%) and infections (28%) were relatively low. There was a low incidence of severe nausea and vomiting (11%) and no treatment-related cardiotoxicity, cerebellar toxicity, or alopecia. Many patients received Mylotarg on an outpatient basis (38% and 41% of patients for the first and second doses, respectively). Among the 142 patients, the median total duration of hospitalization was 24 days; 16% of patients required 7 days of hospitalization or less. CONCLUSION: Administration of the antibody-targeted chemotherapy agent Mylotarg to patients with CD33-positive AML in first relapse induces complete remissions with what appears to be a favorable safety profile.