ASH 2022: David Sallman, MD, Discusses Positive Phase I Dose Escalation Data for PRGN-3006 UltraCAR-T in AML Patients

A study using chimeric antigen receptor (CAR)-T cells has proven to be safe for treating patients with relapsed or refractory acute myeloid leukemia (AML). The agent known as PRGN-3006 also brought remissions among patients who had chemotherapy for lymphodepletion prior to their CAR-T cell procedure (Abstract 4633). After the lead author of the new study, David Sallman, MD, from the Moffitt Cancer Center in Tampa, Florida, had reported the new findings at the 2022 Annual Meeting of the American Society of Hematology, OncTimes Talk correspondent Peter Goodwin interviewed him about the study and about the overall prospects of using CAR-T cells to treat AML.

PRGN-3006 UltraCAR-T is a multigenic autologous chimeric antigen receptor (CAR)-T simultaneously expressing a CAR specifically targeting CD33; membrane bound IL-15 (mbIL15) for enhanced in vivo expansion and persistence; and a kill switch to conditionally eliminate CAR-T cells for an improved safety profile. CD33 is over-expressed on AML blasts with lesser expression on normal hematopoietic stem cells. PRGN-3006 UltraCAR-T drug product is manufactured via an overnight process at medical centers using the Company's proprietary non-viral and UltraPorator systems and released for infusion in patients the next day. The decentralized, overnight UltraCAR-T manufacturing process, which does not use viral vectors or ex vivo activation and expansion of T cells, has the potential to address major limitations of current T cell therapies. PRGN-3006 UltraCAR-T has been granted Orphan Drug Designation and Fast Track Designation in patients with AML by the FDA.

The Phase I/Ib clinical study is designed to enroll in two phases, an initial dose escalation phase followed by a dose expansion phase, to evaluate safety and determine the recommended Phase II dose of PRGN-3006 delivered via intravenous (IV) infusion without lymphodepletion (Cohort 1) or with lymphodepletion (Cohort 2). The study is also evaluating in vivo persistence and anti-tumor activity of PRGN-3006.