Precigen Reveals Early Data From CAR-T Candidate In Blood Cancer Patients

Precigen Inc PGEN presented positive interim data at the ASH Annual Meeting and Exposition from the ongoing Phase 1/1b study of PRGN-3006 UltraCAR-T in relapsed or refractory (r/r) acute myeloid leukemia and higher-risk myelodysplastic syndromes.

• PRGN-3006 UltraCAR-T is a multigenic autologous CAR-T simultaneously expressing a CAR targeting CD33.
• PRGN-3006 was well-tolerated with no dose-limiting toxicities (DLTs) and no neurotoxicity at any dose level. 
• Overall, there was a low incidence of adverse events following PRGN-3006 infusion, and the most common adverse events were decreased lymphocyte count, anemia, and cytokine release syndrome (CRS).
• In the non-lymphodepletion cohort, UltraCAR-T cells could be detected in blood for more than seven months post-infusion. 
• Peak expansion was observed between days 7 and 21 in the peripheral blood.
• Three out of 9 (33%) patients had Stable Disease (SD), with one patient experiencing durable SD for more than seven months with a concomitant reduction in peripheral blast levels.
• In the lymphodepletion cohort, UltraCAR-T cells could be detected in the blood more than three months post-infusion. Peak expansion was observed between days 14 and 21 in the peripheral blood.
• Higher peak expansion (over 10 fold) was observed in the lymphodepletion cohort at the same dose level.
• An ORR of 50% was reported in the lymphodepletion cohort in patients treated at the two lowest dose levels.
• One responder subsequently received allo-HSCT with ongoing survival of over one year.
• Price Action: PGEN shares traded lower by 2.43% at $3.61 during premarket trading on Tuesday.
• Check out our coverage of the American Society of Hematology (ASH) Annual Meeting 2021 here.