The Use of Gemtuzumab Ozogamicin as Salvage Therapy in Patients with Acute Myeloid Leukemia: A Monocentric Real-World Experience.

Background and Objectives: Relapsed or refractory acute myeloid leukemia (r/r AML) is a disease with a poor prognosis. Limited treatment options are available in r/r AML. Here, we administered gemtuzumab ozogamicin (GO) as salvage therapy in twenty-four patients with r/r AML. The aim of the study was to determine the role of GO in r/r AML in real life. Material and Methods: This retrospective observational study recruited 24 adult patients with diagnosed r/r AML from 2018 to 2022. Twenty-four patients with r/r AML were treated with GO. GO treatment was used as monotherapy in 23 patients and in combination with cytarabine in 1 patient. At the time of diagnosis, the risk status of all patients was determined as favorable, intermediate, or adverse according to the 2017 ELN AML guidelines. Results: The median follow-up was 44.3 (13-144) months. Fifteen (62.5%) of the twenty-four patients were in the intermediate-risk cytogenetics group and nine (37.5%) were in the favorable cytogenetics group. The most common adverse events included nausea/vomiting in 79.17% (n = 19) of patients, headache in 62.50% (n = 15), elevated LFTs in 37.50% (n = 9), febrile neutropenia in 25% (n = 6), and bleeding in 25% (n = 6). The most common cause of death was infection. The most common causes of mortality were septic shock, accounting for 33.3% (n = 8) of deaths, and opportunistic lung infection, accounting for 12.5% (n = 3) of deaths. Acute infusion-related toxicities associated with GO were usually transient and, in most cases, responded to the standard of care treatment. After treatment with GO, 16.6% (n = 4) of patients achieved MLFS and 37.5% (n = 9) achieved CR. The overall response rate was 54.1%. The median overall survival time of the patients was 44 months (37.8-50.2 months). Disease-free survival was 22 months (0-48.6 months). The 5-year survival rate was 33%. Conclusions: A low dose of GO improved the overall survival and disease-free survival in r/r AML patients. GO treatment had a positive safety profile in terms of toxicity.