Michael Tees, MD, MPH, Colorado Blood Cancer Institute, Denver, CO, discuss a safety and pharmacodynamics (PD)/pharmacokinetics (PK) study of ALLO-647, an anti-CD52 antibody, with fludarabine (FLU)/cyclophosphamide (CY) for lymphodepletion in the setting of allogeneic CAR T-cell therapy. ALPHA (NCT03939026) and UNIVERSAL (NCT04093596) are ongoing trials in hematological malignancies assessing ALLO-501 and ALLO-715 allogeneic CAR T-cell therapy, respectively. ALLO-647 was used in both studies for lymphodepletion. Findings from the 72 patients treated as of the data cut-off demonstrated that ALL0-647 with FLU plus CY had a tolerable safety profile and produced a deep and durable window of lymphocyte depletion. Higher doses were associated with greater incidence and severity of infusion-related reactions, but also higher IL-15 levels and better CAR-T expansion, suggesting dose responses. This interview took place at the American Society of Clinical Oncology (ASCO) 2021 Virtual Meeting.