A Phase 1/2 interventional study of VCAR33 in Leukemia, Myeloid, Acute, sponsored by Vor Biopharma. Terminated at 14 sites in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-07-29.
Sponsored by Vor Biopharma · Phase 1/2, Interventional, and Treatment
This is a Phase 1/2, multicenter, open-label, first-in-human (FIH) study of donor-derived anti-CD33 Chimeric Antigen Receptor (CAR) T cell therapy (VCAR33) in patients with relapsed or refractory Acute Myeloid Leukemia (AML) after human leukocyte antigen (HLA)-matched allogeneic hematopoietic cell transplant (alloHCT).
CD33 is a preferential target for AML CAR T cell therapy due to its surface expression on the majority (>80%) of AML blasts and due to the extensive prior clinical experience demonstrating safety and efficacy of targeting CD33 with Mylotarg (gemtuzumab ozogamicin). VCAR33 is being developed as a potential new treatment for patients with relapsed/refractory (R/R) AML after alloHCT. In this Phase 1/2 trial, the safety and efficacy of lentiviral-transduced CD33-directed CAR T cells (VCAR33) generated from the patient's prior allogeneic stem cell donor will be tested. It is hypothesized that CAR T cell production from healthy donors will not only eliminate delays in production due to lymphopenia but also reduce concerns for suboptimal T cell function from exposure to systemic immunosuppression or chemotherapeutic agents. Approximately 24 eligible patients with R/R AML after alloHCT will be enrolled in one of two separate arms based on disease burden (morphologic disease versus measurable residual disease (MRD ) positive). The maximum tolerated dose of VCAR33 will be determined using a 3+3 trial design within each arm. Dose escalation can only occur after a minimum of 3 patients have completed the dose-limiting toxicity (DLT) observation period.
3,667 studies on the registry are indexed under Leukemia, Myeloid, Acute; 816 are open to participants now.
This study's enrollment of 38 is close to the median of 40 across 3,005 interventional studies indexed under Leukemia, Myeloid, Acute.
Browse Leukemia, Myeloid, Acute studies →Vor Biopharma is the lead sponsor of 7 studies on the registry; 1 is open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Disease status at the time of enrollment:
Patient must have adequate organ function as defined by:
Exclusion Criteria:
Patients with the following prior therapy:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Relapsed: the illness came back after treatment had worked. Refractory: it did not respond to treatment, or stopped responding while still on it.
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.
After a transplant from a donor, the donor’s immune cells attack the recipient’s body, often the skin, gut or liver.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Relapsed and refractory
Relapsed: the illness came back after treatment had worked. Refractory: it did not respond to treatment, or stopped responding while still on it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ECOG performance status
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
LVEF (left ventricular ejection fraction)
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Bilirubin
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Creatinine clearance (CrCl)
How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GVHD (graft-versus-host disease)
After a transplant from a donor, the donor’s immune cells attack the recipient’s body, often the skin, gut or liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
VCAR33 Dose Level 1
Biological: VCAR33
VCAR33 Dose Level 2
Biological: VCAR33
VCAR33 Dose Level 3
Biological: VCAR33
VCAR33 Dose Level 1
Biological: VCAR33
VCAR33 Dose Level 2
Biological: VCAR33
VCAR33 Dose Level 3
Biological: VCAR33
Allogeneic Anti-CD33 Chimeric Antigen Receptor (CAR) T Cell therapy
Incidence of dose-limiting toxicities
Time frame: Day 28
Incidence of GVHD related to VCAR33
Time frame: Up to 24 months
Percentage of patients who achieve response
Time frame: Up to 24 months
Overall survival post-VCAR33 infusion
Time frame: Up to 24 months
Progression-free survival post-VCAR33 infusion
Time frame: Up to 24 months
This study is terminated, as verified in May 2025. You cannot join it, but the record below documents what was studied.
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