Optimised CD33 (FL-33) CAR T Therapy for Refractory/Relapsed Acute Myeloid Leukaemia

May 20, 2026 updated by: Jing Pan, Beijing GoBroad Hospital

Optimised CD33 (FL-33) CAR T Therapy for Refractory/Relapsed Acute Myeloid Leukaemia：a Multi-center, Open-label, Non-randomised, Single-arm Phase Ⅰ Clinical Trial

This study is a multi-center, open-label, non-randomised, single-arm phaseⅠclinical trial to explore the safety and efficacy of FL-33 CAR T therapy for refractory/relapsed acute myeloid leukaemia. The primary endpoints are incidence and type of dose limiting toxicity within 21 days of CAR T infusion; total number, incidence and severity of adverse events (AE) 30 days after CAR T infusion. The secondary endpoints are total number, incidence and severity of AEs 30 days to 2 years after CAR T infusion; objective response rate (ORR), complete response rate (CR) and complete response with incomplete haematological recovery (CRi) by dose group at 15, 30 and 90 Days after CAR T Infusion; duration of response (DOR), progression-free survival (PFS), overall survival (OS); pharmacokinetic characteristics. The trial will use BOIN12 design to explore the optimal biological dose (OBD) of FL-33 CAR T cells for refractory/relapsed acute myeloid leukaemia. FL-33 CAR T is set at two dose levels: 5*10^5 (±20%) CAR-T cells/kg for dose 1 (DL-1) and 1*10^6 (±20%) CAR-T cells/kg for dose 2 (DL-2), and after the optimal biological dose (OBD) is determined in the dose exploration phase, the dose expansion phase will expand the trial by 6-12 cases at the OBD, enrolling up to 21-27 cases. Enrolment of more than 21 cases can be reported for analysis and the trial will be stopped when enrolment reaches 27 cases.Additionally, an independent observation group was established, comprising two sequential cohorts: a minimum of 3 subjects were enrolled starting from the lowest dose level (DL-1).

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
27

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • China
    • Shanghai Municipality
      • Shanghai, Shanghai Municipality, China, 200435
        • Not yet recruiting
        • Zhaxin Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai
      • Shanghai, Shanghai Municipality, China, 201418
        • Not yet recruiting
        • Shanghai Liquan Hospital
    • Sichuan
      • Chengdu, Sichuan, China, 610083
        • Not yet recruiting
        • The General Hospital of Western Theater Command PLA

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Patients who met all the inclusion criteria were eligible for enrolment.

    1. Patients diagnosed with primary resistance acute myeloid leukemia, tumour surface antigen CD33 expression, chemotherapy relapse, extramedullary relapse, persistent residual positivity or relapse/refractory after allogeneic haematopoietic stem cell transplantation;
    2. Age 1-70 years old;
    3. No severe allergies;
    4. Physical condition: 0-2 ECOG score;
    5. Expected survival ≥ 60 days;
    6. Bone marrow or cerebrospinal fluid tumour cells are positive for CD33 by flow cytometry assay or tumour tissues positive for CD33 by immunohistochemistry (CD33 determination of positivity: flow cytometry: >80% of tumour cells expressing CD33 and MFI similar to normal myeloid cells is considered as full positivity; tumour cells greater than 80% of expression of CD33 but MFI lower than the CD33 expression of normal myeloid cells by 1 log is considered as low expression (dim). Tumour cells with between 20-80% positive CD33 expression are partially expressed; Pathological immunohistochemistry: tumour cells>30% positive are considered to be positively expressed;
    7. Self-aware patients aged 19-70 years are required to voluntarily sign an informed consent form in writing; paediatric patients aged 1-7 years can be recruited after their legal representative (guardian) had signed an informed consent form; self-aware paediatric patients aged 8-18 years voluntarily sign an informed consent form in writing, and their legal representative (guardian) are required to sign an informed consent form in writing as well;
    8. Suitable and available allogeneic haematopoietic stem cell transplant donors are required, and allogeneic haematopoietic stem cell transplantation can be performed after receiving FL-33 CAR T treatment.

Exclusion Criteria:

  • Patients who fulfil any of the following criteria may not be enrolled.

    1. Patients with history of allogeneic HSCT but PBMNC is not available from prior- transplant donor for preparation of CAR T cells and peripheral blood tumour load >30%; patients without history of allogeneic HSCT and peripheral blood tumour load >30%;
    2. Intracranial hypertension or cerebral impaired consciousness;
    3. Symptomatic heart failure or severe arrhythmia;
    4. Symptoms of severe respiratory failure;
    5. With other types of malignancy;
    6. Diffuse intravascular coagulation;
    7. Serum creatinine and/or urea nitrogen ≥ 1.5 times the normal value;
    8. With sepsis or other uncontrollable infection;
    9. Suffering from uncontrollable diabetes mellitus;
    10. Severe mental disorders;
    11. Have significant intracranial lesions on cranial MRI;
    12. Organ transplantation (excluding haematopoietic stem cell transplantation) history;
    13. Female patients (patients of childbearing potential) with positive blood HCG test;
    14. Hepatitis (including hepatitis B and C) and positive screening for AIDS and syphilis.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Autologous FL-33 CAR T
Peripheral blood mononuclear cells for the production of FL-33 CAR T cells are collected from patients.
Drug: autologous FL-33 CAR T therapy
Autologous FL-33 CAR T cells are infused intravenously.
Experimental: Prior-HSCT donor-derived FL-33 CAR T
Peripheral blood mononuclear cells for the production of FL-33 CAR T cells are collected from prior-HSCT donors.
Drug: prior-HSCT donor-derived FL-33 CAR T therapy
Prior-HSCT donor-derived FL-33 CAR T cells are infused intravenously.
Experimental: Newly matched donor-derived FL33 CAR T
Peripheral blood mononuclear cells for the production of FL-33 CAR T cells are collected from newly matched donors.
Drug: Newly matched donor-derived FL-33 CAR T therapy
Newly matched donor-derived FL-33 CAR T cells are infused intravenously
Experimental: FL-33-03 CAR T
The independent observation group, serving as an exploratory arm, will uniformly enroll at least 3 subjects starting from the lowest dose level (DL-1) into Cohort 1 to evaluate the safety and efficacy of FL33-03 CAR-T (with TNFα inhibitor). If the results from this stage meet expectations, at least 3 additional subjects will be enrolled into Cohort 2 to evaluate the safety and efficacy of FL33-03 CAR-T (without TNFα inhibitor) at the same lowest dose level.
Drug: FL33-03 CAR-T therapy
Optimized FL-33-03 CAR-T cells

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Dose-limiting toxicity(DLT)
Time Frame: 21 days
Incidence and type of dose-limiting toxicity(DLT) within 21 days of FL-33 CAR T infusion.
21 days
Adverse events (AEs)
Time Frame: 30 days
Total number, incidence and severity of adverse events (AEs) within 30 days of FL-33 CAR T infusion.
30 days

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Long-term Adverse events (AEs)
Time Frame: From 30 days after FL-33 CAR T infusion to 2 years
Total number, incidence and severity of AEs from 30 days to 2 years after FL-33 CAR T infusion will be recorded.
From 30 days after FL-33 CAR T infusion to 2 years
Objective Response Rate (ORR)
Time Frame: 15, 30, 90 days
The assessment of ORR by dose group at 15, 30 and 90 Days after FL-33 CAR T infusion according to National Comprehensive Cancer Network (NCCN) Guidelines Version 1.2024 of Acute myeloid Leukemia.
15, 30, 90 days
Duration of response (DOR)
Time Frame: Up to 2 years
DOR is defined as the date when CR or CRi response criteria are first met to the date of relapse or death caused by AML in the absence of documented relapse.
Up to 2 years
Progression-free survival (PFS)
Time Frame: Up to 2 years
PFS is defined as the earliest date of occurrence from the first infusion of FL-33 CAR T cells back into the patient who achieved ORR to the earliest date of death from any cause after relapse or remission.
Up to 2 years
Overall survival (OS)
Time Frame: Up to 2 years
OS is defined as the time from FL-33 CAR T infusion to death due to any cause.
Up to 2 years
The persistence of FL-33 CAR T cells
Time Frame: Up to 2 years
The persistence of FL-33 CAR T cells in cerebral spinal fluid (CSF) and peripheral blood (PB) will be measured by flowcytometry and quantitative polymerase chain reaction (qPCR).
Up to 2 years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Beijing GoBroad Hospital

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Ruijin Hospital
The General Hospital of Western Theater Command
Zhaxin Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai
Shanghai Liquan Hospital

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
April 2, 2024

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
June 15, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 30, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
March 10, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 15, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
March 22, 2024

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
May 22, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 20, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
March 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • BJGBYY-IIT-LCYJ-2024-004

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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