BioTuesdays

Precigen reports positive interim Phase 1 data in r/r AML

Precigen (NASDAQ:PGEN) presented positive interim data at the ASH annual meeting from an ongoing Phase 1/1b clinical study of PRGN-3006 UltraCAR-T in patients with relapsed or refractory (r/r) acute myeloid leukemia (AML) and higher-risk myelodysplastic syndromes (MDS).

The oral presentation was delivered by David Sallman, M.D., assistant member in the department of malignant hematology at the H. Lee Moffitt Cancer Center & Research Institute and a lead investigator for the PRGN-3006 clinical trial.

PRGN-3006 UltraCAR-T is a multigenic autologous CAR-T simultaneously expressing a CAR specifically targeting CD33; membrane bound IL-15 for enhanced in vivo expansion and persistence; and a kill switch to conditionally eliminate CAR-T cells for an improved safety profile.

Among other things, the study’s finding included:

• A single administration of UltraCAR-T cells following overnight manufacturing demonstrated robust expansion and persistence in blood and bone marrow with or without lymphodepletion.
• Patient case study demonstrated the ability of UltraCAR-T cells to persist and reactivate upon the reoccurrence of tumor blasts.
• Objective response rate of 50%, one partial response and two complete responses for the lymphodepletion cohort at the two lowest dose levels.
• One responder in the lymphodepletion cohort subsequently bridged to allo-HSCT with ongoing survival greater than one year.
• Stable disease for more than three months in 33% of patients in the non-lymphodepletion cohort.
• PRGN-3006 UltraCAR-T demonstrated a very favorable safety profile with no dose-limiting toxicities and no neurotoxicity.
• And gene expression data showed enhancement in the cytotoxicity, costimulatory signaling, and lymphoid compartment pathways and a decrease in the apoptosis pathways in the responding patients following low dose PRGN-3006 infusion in the lymphodepletion cohort.

“We are excited by these interim data, which clearly highlight the extraordinary potential and flexibility of the UltraCAR-T platform to deliver precision medicine to patients at any time, at any place and as many times as needed,” Helen Sabzevari, Ph.D., president and CEO of Precigen, said in a statement.

“Based on the favorable safety profile and excellent expansion observed for both the lymphodepletion and the non-lymphodepletion cohorts, we believe UltraCAR-T cells have the potential to improve outcomes for cancer patients,” she added.

Sign up for the BioTuesdays weekly newsletter

Get the latest news on the healthcare industry’s corporate and clinical developments, executive moves, and market updates. Every Tuesday, in your inbox.