Allogeneic dendritic cell (DC) vaccination as an “off the shelf” treatment to prevent or delay relapse in elderly acute myeloid leukemia patients: Results of phase I study.

3029 Background: Vaccines against tumor-associated antigens represent an appealing strategy for preventing tumor recurrence. A novel immunotherapy platform is represented by the DCOne cell line, which originates from a human myeloid leukemia cell line, endogenously expresses a range of tumor associated antigens and can be differentiated into mature dendritic cells. Methods: A phase I study enrolled 12 AML patients (age range 58-71) who were either in CR1/CR2 (n=5) or had smouldering disease (n=7), at high risk of relapse and ineligible for available post-remission therapies, in a 3+3 design, starting with 4 bi-weekly intradermal DCOne DC vaccinations of 10E6 cells (n=3), 25E6 (n=3) or 50E6 (n=6). Patients were monitored for clinical and immunological responses for 126 days and surviving patients were followed up after study completion. Results: Treatment was well tolerated in all patients, with expected toxicities of injection site reactions (< grade 2). During the study 3 patients died: 2 from infections...