Phase 1/2 trial of VCAR33 after HCT

The VBP301 clinical trial studies VCAR33^ALLO, a CD33-targeted CAR-T cell therapy derived from allogeneic healthy donors.

This trial includes patients who have relapsed following allogeneic stem cell transplant, including patients who have previously received trem‑cel.

Mylotarg, an Antibody Drug Conjugate (ADC), is currently the only anti-CD33 therapy approved by the FDA. We believe that our CAR-T product candidate, VCAR33^ALLO, may ultimately be a better targeted therapy due to higher expected potency and target specificity.

Study goals

The primary goal of the VBP301 clinical trial is to determine the safety and maximum tolerated dose (MTD) of VCAR33^ALLO in patients with relapsed or refractory AML after allogeneic hematopoietic cell transplantation (alloHCT). Secondary goals include evaluating the incidence of VCAR33^ALLO -related toxicities and determining the efficacy of VCAR33^ALLO in these patients.

Enrollment & follow-up

The VBP301 trial is open to CD33+ AML patients in relapse or refractory after alloHCT. Participants aged 18 and older must be a recipient of an 8/8 HLA-matched related or unrelated donor alloHCT. Patients previously transplanted with trem-cel in the VBP101 study who have relapsed or refractory AML may also be considered. Additional key inclusion criteria include either morphologic remission with 5% or more bone marrow-only blasts or minimal residual disease with greater than 5% bone marrow-only blasts. Key exclusion criteria include having had more than one prior alloHCT.

To produce VCAR33^ALLO, T cells harvested from the original HCT donor are used as starting material for the drug product. VCAR33^ALLO will be administered to the patient following a lymphodepleting regimen. Patients will remain hospitalized at least through approximately Day 7 to monitor for post-infusion reactions. After discharge, patients will be closely monitored through Day 28. Subsequently, patients will return to the clinic for follow-up assessments at regular intervals and will be followed for up to 15 years post- VCAR33^ALLO infusion in a separate long-term follow-up study.

To learn more about our clinical trial, VBP301, please see our clinicaltrials.gov listing:

VBP301 – Donor-Derived Anti-CD33 CAR T Cell Therapy (VCAR33) in Patients With Relapsed or Refractory AML After Allogeneic Hematopoietic Cell Transplant

If you have questions, please contact us.