FT538 is an off the shelf product comprised of allogeneic natural killer (NK)-cell immunotherapy lacking CD38 and expressing hnCD16 and IL-15RF. Daratumumab is a targeted therapy (IgG1k human monoclonal antibody) that targets CD38.~FT538 is administered once a week for 3 consecutive weeks (Day 1, Day 8, and Day 15). Up to 5 dose levels will be tested. Fixed dose subcutaneous daratumumab is given on Day -12 and Day 5 prior to the NK cells as lymphodepletion, and on Day +3, Day +10, and Day +17 to maximize targeting. A short course of outpatient lymphodepleting chemotherapy is given on Day -4 and Day -3 to promote adoptive transfer. Day 1, the day of the 1st FT538 infusion, must be a Monday.~The primary analysis for Phase I is intent-to-treat in that all patients receiving the 1st infusion of FT538 are evaluable for toxicity and efficacy. Patients who discontinue therapy prior to the first FT538 will be replaced.~There are five potential FT538 dose cohorts. The starting dose is FT538 1x10e8 cells per dose with a lower safety dose of 5x10e7 if needed (Dose Level -1). The subsequent planned FT538 cohorts are 3x10e8, 1x10e9, and 1.5 x10e9 FT538 cells per dose. Dosing is based on hnCD16 expression, where 90% ± 10% of administered FT538 cells express hnCD16. The trial is conducted with no intra-patient escalation.
This Phase I open-label dose escalation study is conducted in two stages with a primary endpoint to identify the maximum tolerated dose (MTD) of FT538 when administered with daratumumab in patients 12 years and older with advanced acute myeloid leukemia (AML) and related myeloid diseases.