Phase 1/2 Study of Donor-Derived Anti-CD33 Chimeric Antigen Receptor Expressing T Cells (VCAR33ALLO) in Patients with Relapsed or Refractory Acute Myeloid Leukemia After Allogeneic Hematopoietic Cell Transplantation (Trial in Progress)
We are developing a Chimeric Antigen Receptor T (CAR-T) cell product candidate, VCAR33ALLO, that targets the CD33 protein.
VCAR33ALLO is manufactured from lymphocytes collected from the patient’s original transplant donor, generating a CAR-T cell therapy that is exactly matched to the recipient’s engrafted blood system. By using healthy transplant donor cells as the starting material to produce VCAR33ALLO, the CAR-T cells have a more stem-like phenotype, leading to greater potential for expansion, persistence and anti-leukemia activity compared to a product derived from a patient’s own lymphocytes.
Vor Bio operates an in-house cell therapy manufacturing facility that is being used to manufacture VCAR33ALLO, using an abbreviated manufacturing process to maintain a stem-like cell phenotype alongside robust transduction of the CAR construct.
VCAR33ALLO has been granted Orphan Drug Designation and Fast Track designation from the U.S. Food and Drug Administration.
VCAR33ALLO Clinical Development
We are actively enrolling VBP301 (NCT05984199), a Phase 1/2, multicenter, open-label, first-in-human study of VCAR33ALLO in patients with relapsed or refractory AML after standard-of-care transplant or a trem-cel transplant.
The trial is evaluating safety, as well as key outcome measures including incidence of graft-versus-host disease related to VCAR33, percentage of patients who achieve response and overall survival and progression-free survival post-VCAR33 infusion.
The first phase, which is expected to enroll approximately 12 patients, is designed to determine the maximum tolerated dose of VCAR33ALLO using a 3+3 trial design; the second phase, which is expected to enroll up to 12 patients, is an expansion phase designed to evaluate the rate of clinical response to treatment. The trial is designed to test the hypothesis that a CD33-targeted CAR-T derived from a healthy donor can be safely administered to a patient with AML who has relapsed after transplant and that the CAR-T can demonstrate anti-leukemia activity.