Anti-FLT3 CAR-T Cells for AML
Recruiting in Palo Alto (17 mi)
Age: 18+
Sex: Any
Travel: May Be Covered
Time Reimbursement: Varies
Trial Phase: Phase 1
Recruiting
Sponsor: Hemogenyx Pharmaceuticals LLC
Must not be taking: Steroids, Immunosuppressants
Disqualifiers: Pregnancy, Active malignancy, Hepatitis, others
No Placebo Group
Trial Summary
What is the purpose of this trial?
This is a phase 1 dose escalation study to determine the safety of anti-FLT3 CAR-T in subjects with R/R AML. The primary objective is to assess safety. Up to 18 evaluable subjects will be enrolled. Evaluable subjects are defined as those who have received an infusion of HG-CT-1. Primary clinical objectives: i. Determine the safety of HG-CT-1 based on the proportion of subjects infused with HG-CT-1 who experience a dose limiting toxicity (DLT). Secondary clinical objectives: i. Estimate the efficacy of HG-CT-1 according to standard clinical response criteria for AML. ii. Estimate overall survival of evaluable subjects. iii. Estimate progression-free survival of evaluable subjects. iv. Estimate duration of response in evaluable subjects who achieve a response. Secondary scientific objectives: i. Describe the persistence and trafficking of HG-CT-1. ii. Describe HG-CT-1 bioactivity and its predictors.
Will I have to stop taking my current medications?
The trial protocol does not specify if you need to stop taking your current medications. However, you cannot participate if you are using certain immunosuppressant medications or high doses of systemic steroids.
What data supports the effectiveness of the Anti-FLT3 CAR-T cell treatment for AML?
Research shows that Anti-FLT3 CAR-T cells can effectively target and kill AML cells with a specific mutation (FLT3-ITD), especially when used with another drug called crenolanib. This combination enhances the ability of the CAR-T cells to recognize and attack the cancer cells, suggesting a promising approach for treating this type of leukemia.12345
Is Anti-FLT3 CAR-T cell therapy safe for humans?
How is the Anti-FLT3 CAR-T cell treatment different from other treatments for AML?
The Anti-FLT3 CAR-T cell treatment is unique because it uses genetically engineered T-cells to specifically target and kill AML cells with the FLT3 mutation, offering a novel approach compared to traditional chemotherapy. This treatment can be combined with FLT3 inhibitors like crenolanib to enhance its effectiveness, and it includes an 'off-switch' to help manage potential side effects, such as myelotoxicity (damage to bone marrow).23479
Eligibility Criteria
This trial is for individuals with relapsed or refractory Acute Myeloid Leukemia (AML), including childhood cancer and granulocytic leukemia. Participants must have previously received treatments that are no longer effective.Inclusion Criteria
Subjects must have a suitable stem cell transplant donor
I had a transplant, am not on immunosuppressants for 1 month, and have no GvHD needing them.
I am fully active or can carry out light work.
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Exclusion Criteria
I had a stem cell transplant from a donor under specific conditions.
I do not have active hepatitis B, hepatitis C, or HIV.
Known history of allergy or hypersensitivity to study product excipients
See 9 more
Trial Timeline
Screening
Participants are screened for eligibility to participate in the trial
2-4 weeks
Treatment
Participants receive an infusion of HG-CT-1 CAR-T cells, with dose escalation to determine safety
4 weeks
Multiple visits for infusion and monitoring
Follow-up
Participants are monitored for safety and effectiveness after treatment, including assessment of dose-limiting toxicities and clinical response
12 months
Regular visits at Day 14, Day 28, Month 3, Month 6, and Month 12
Treatment Details
Interventions
- Anti-FLT3 CAR-T cells (CAR T-cell Therapy)
Trial OverviewThe study tests a new therapy called Anti-FLT3 CAR-T cells, aiming to determine its safety at different doses in up to 18 subjects who will receive an infusion of HG-CT-1, the study drug.
Participant Groups
4Treatment groups
Experimental Treatment
Group I: Dose level 3: 3.5x10^8 Transduced CAR+ HG-CT-1Experimental Treatment1 Intervention
Group II: Dose level 2: 1.4x10^8 Transduced CAR+ HG-CT-1Experimental Treatment1 Intervention
Group III: Dose level 1: 7x10^7 Transduced CAR+ HG-CT-1Experimental Treatment1 Intervention
Group IV: Dose level -1: 3.5 x 10^7 Transduced CAR+ HG-CT-1Experimental Treatment1 Intervention
Find a Clinic Near You
Research Locations NearbySelect from list below to view details:
MD AndersonHouston, TX
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Who Is Running the Clinical Trial?
Hemogenyx Pharmaceuticals LLCLead Sponsor
MD Anderson Cancer Center University of TexasCollaborator
References
Targeting FLT3 for the treatment of leukemia. [2021]FLT3 is a receptor tyrosine kinase with important roles in hematopoietic stem/progenitor cell survival and proliferation. It is frequently overexpressed in acute leukemias and is frequently mutated in acute myeloid leukemia (AML). FLT3 internal tandem duplication (ITD) mutations in AML portend poor prognosis in both adult and pediatric patients. A number of small molecule tyrosine kinase inhibitors (TKIs) with activity against FLT3 have been discovered. Many of these are still in preclinical development, but several have entered clinical phase I and II trials as monotherapy in patients with relapsed AML. These trials have resulted in frequent but short-lived responses of peripheral blasts and less frequent responses of bone marrow blasts. This led to clinical testing of FLT3 TKIs in combination with conventional chemotherapy. Several combination trials are ongoing or planned in both relapsed and newly diagnosed FLT3-mutant AML patients. Anti-FLT3 antibodies may also prove to be an excellent way of targeting FLT3 in AML and acute lymphocytic leukemia (ALL) by inhibiting signaling and through antibody-dependent cell-mediated cytotoxicity.
Natural Flt3Lg-Based Chimeric Antigen Receptor (Flt3-CAR) T Cells Successfully Target Flt3 on AML Cell Lines. [2021]Relapsed/refractory acute myeloid leukemia (AML) cannot be cured with chemotherapy alone, as the blasts survive the treatment. Chimeric antigen receptor (CAR) approaches for AML are being actively developed. CARs promote immune reactions through recognition of the target molecular epitopes at the surface of cancer cells. The recognition involves the extracellular portion of the CAR protein, which corresponds to either the antibody or the physiological binding partner of the targeted antigen. Here, we design a chimeric receptor with a full-length natural Flt3-ligand recognition module that targets Flt3 tyrosine kinase, known as an adverse marker in AML. We demonstrate specific killing of Flt3-positive THP-1 cells by Flt3-CAR T cells and the lack of cytotoxicity towards Flt3-negative U937 cells. We prove that the inherent cytolytic capacity of T cells is essential for the killing. Finally, we confirm the authenticity of targeting by its competitive dose-dependent inhibition with a soluble Flt3-ligand. The developed system can be viewed as a non-immunogenic functional equivalent of scFv-mediated targeting. The robust in vitro antitumor effects of Flt3-CAR T cells, combined with their low off-target cytotoxicity, hold promise for AML treatment.
CAR T-cells targeting FLT3 have potent activity against FLT3-ITD+ AML and act synergistically with the FLT3-inhibitor crenolanib. [2019]FMS-like tyrosine kinase 3 (FLT3) is a transmembrane protein expressed on normal hematopoietic stem and progenitor cells (HSC) and retained on malignant blasts in acute myeloid leukemia (AML). We engineered CD8+ and CD4+ T-cells expressing a FLT3-specific chimeric antigen receptor (CAR) and demonstrate they confer potent reactivity against AML cell lines and primary AML blasts that express either wild-type FLT3 or FLT3 with internal tandem duplication (FLT3-ITD). We also show that treatment with the FLT3-inhibitor crenolanib leads to increased surface expression of FLT3 specifically on FLT3-ITD+ AML cells and consecutively, enhanced recognition by FLT3-CAR T-cells in vitro and in vivo. As anticipated, we found that FLT3-CAR T-cells recognize normal HSCs in vitro and in vivo, and disrupt normal hematopoiesis in colony-formation assays, suggesting that adoptive therapy with FLT3-CAR T-cells will require subsequent CAR T-cell depletion and allogeneic HSC transplantation to reconstitute the hematopoietic system. Collectively, our data establish FLT3 as a novel CAR target in AML with particular relevance in high-risk FLT3-ITD+ AML. Further, our data provide the first proof-of-concept that CAR T-cell immunotherapy and small molecule inhibition can be used synergistically, as exemplified by our data showing superior antileukemia efficacy of FLT3-CAR T-cells in combination with crenolanib.
A novel approach for relapsed/refractory FLT3mut+ acute myeloid leukaemia: synergistic effect of the combination of bispecific FLT3scFv/NKG2D-CAR T cells and gilteritinib. [2022]Patients with relapsed/refractory acute myeloid leukaemia (AML) with FMS-like tyrosine kinase 3-internal tandem duplication (FLT3-ITD) have limited treatment options and poor prognosis. Therefore, novel treatment modalities are needed. Since high expression of natural killer group 2 member D ligands (NKG2DLs) can be induced by FLT3 inhibitors, we constructed dual-target FLT3 single-chain fragment variable (scFv)/NKG2D-chimeric antigen receptor (CAR) T cells, and explored whether FLT3 inhibitors combined with FLT3scFv/NKG2D-CAR T cells could have synergistic anti-leukaemia effects.
Recent Advances in the Development of Anti-FLT3 CAR T-Cell Therapies for Treatment of AML. [2022]Following the success of the anti-CD19 chimeric antigen receptor (CAR) T-cell therapies against B-cell malignancies, the CAR T-cell approach is being developed towards other malignancies like acute myeloid leukemia (AML). Treatment options for relapsed AML patients are limited, and the upregulation of the FMS-like tyrosine kinase 3 (FLT3) in malignant T-cells is currently not only being investigated as a prognostic factor, but also as a target for new treatment options. In this review, we provide an overview and discuss different approaches of current anti-FLT3 CAR T-cells under development. In general, these therapies are effective both in vitro and in vivo, however the safety profile still needs to be further investigated. The first clinical trials have been initiated, and the community now awaits clinical evaluation of the approach of targeting FLT3 with CAR T-cells.
Targeting FLT3 in acute myeloid leukemia using ligand-based chimeric antigen receptor-engineered T cells. [2019]Label="BACKGROUND">Chimeric antigen receptor-engineered T (CAR-T) cells have extraordinary effect in treating lymphoblastic leukemia. However, treatment of acute myeloid leukemia (AML) using CAR-T cells remains limited to date. Leukemogenesis always relates with the abnormalities of cytogenetics, and nearly one third of AML patients have activating mutations in Fms-like tyrosine kinase 3 (FLT3) which reminded poor prognosis. Considering the FLT3 expressed in AML patients' blast cells, it may be a new candidate target for CAR-T therapy to treat FLT3+ AML, especially patients harboring FLT3-ITD mutation.
Allogeneic FLT3 CAR T Cells with an Off-Switch Exhibit Potent Activity against AML and Can Be Depleted to Expedite Bone Marrow Recovery. [2021]Patients with relapsed or refractory acute myeloid leukemia (AML) have a dismal prognosis and limited treatment options. Chimeric antigen receptor (CAR) T cells have achieved unprecedented clinical responses in patients with B cell leukemias and lymphomas and could prove highly efficacious in AML. However, a significant number of patients with AML may not receive treatment with an autologous product due to manufacturing failures associated with low lymphocyte counts or rapid disease progression while the therapeutic is being produced. We report the preclinical evaluation of an off-the-shelf CAR T cell therapy targeting Fms-related tyrosine kinase 3 (FLT3) for the treatment of AML. Single-chain variable fragments (scFvs) targeting various epitopes in the extracellular region of FLT3 were inserted into CAR constructs and tested for their ability to redirect T cell specificity and effector function to FLT3+ AML cells. A lead CAR, exhibiting minimal tonic signaling and robust activity in vitro and in vivo, was selected and then modified to incorporate a rituximab-responsive off-switch in cis. We found that allogeneic FLT3 CAR T cells, generated from healthy-donor T cells, eliminate primary AML blasts but are also active against mouse and human hematopoietic stem and progenitor cells, indicating risk of myelotoxicity. By employing a surrogate CAR with affinity to murine FLT3, we show that rituximab-mediated depletion of FLT3 CAR T cells after AML eradication enables bone marrow recovery without compromising leukemia remission. These results support clinical investigation of allogeneic FLT3 CAR T cells in AML and other FLT3+ hematologic malignancies.
Nonclinical Safety Assessment of AMG 553, an Investigational Chimeric Antigen Receptor T-Cell Therapy for the Treatment of Acute Myeloid Leukemia. [2021]Feline McDonough Sarcoma-like tyrosine kinase 3 (FLT3), a tyrosine-protein kinase involved in hematopoiesis, is detectable on the cell surface of approximately 80% of leukemia isolates from adult patients with acute myeloid leukemia (AML). AMG 553 is an investigational chimeric antigen receptor (CAR) T-cell immunotherapy for the treatment of AML. FLT3 expression analysis and in vitro and in vivo studies were leveraged to evaluate the nonclinical safety of AMG 553. Cynomolgus monkeys administered autologous anti-FLT3 CAR T cells demonstrated no evidence of CAR T-cell-mediated toxicity, expansion, or persistence, likely due to restricted cell surface FLT3 protein expression in healthy animals. This highlights the limited value of such in vivo studies for safety assessment of the CAR T-cell modality when directed against a target with restricted expression. To complement these studies and directly evaluate the potential toxicities of eliciting T-cell-mediated cytotoxicity against cells with surface expression of FLT3 protein in vivo, data from cynomolgus monkey toxicology studies with 2 bispecific T-cell engager molecules targeting FLT3 were leveraged; findings were consistent with the targeted killing of bone marrow cells expressing cell surface FLT3. Potential AMG 553-induced cytotoxicity was assessed against a wide range of normal human primary cells and cell lines; cytotoxicity was observed against FLT3-positive AML cell lines and a percentage of primary bone marrow CD34+ cells. In conclusion, the nonclinical safety data suggest that AMG 553 can target FLT3 protein on AML cells, whereas only affecting a percentage of normal hematopoietic stem and progenitor cells, supporting clinical development.
Potent preclinical activity of FLT3-directed chimeric antigen receptor T-cell immunotherapy against FLT3- mutant acute myeloid leukemia and KMT2A-rearranged acute lymphoblastic leukemia. [2023]Chimeric antigen receptor (CAR) T-cell immunotherapies targeting CD19 or CD22 induce remissions in the majority of patients with relapsed/refractory B-cell acute lymphoblastic leukemia (ALL), although relapse due to target antigen loss or downregulation has emerged as a major clinical dilemma. Accordingly, great interest exists in developing CAR T cells directed against alternative leukemia cell surface antigens that may help to overcome immunotherapeutic resistance. The fms-like tyrosine kinase 3 receptor (FLT3) is constitutively activated via FLT3 mutation in acute myeloid leukemia (AML) or wild-type FLT3 overexpression in KMT2A (lysine-specific methyltransferase 2A)-rearranged ALL, which are associated with poor clinical outcomes in children and adults. We developed monovalent FLT3-targeted CAR T cells (FLT3CART) and bispecific CD19xFLT3CART and assessed their anti-leukemia activity in preclinical models of FLT3-mutant AML and KMT2A-rearranged infant ALL. We report robust in vitro FLT3CART-induced cytokine production and cytotoxicity against AML and ALL cell lines with minimal cross-reactivity against normal hematopoietic and non-hematopoietic tissues. We also observed potent in vivo inhibition of leukemia proliferation in xenograft models of both FLT3-mutant AML and KMT2A-rearranged ALL, including a post-tisagenlecleucel ALL-to-AML lineage switch patient-derived xenograft model pairing. We further demonstrate significant in vitro and in vivo activity of bispecific CD19xFLT3CART against KMT2Arearranged ALL and posit that this additional approach might also diminish potential antigen escape in these high-risk leukemias. Our preclinical data credential FLT3CART as a highly effective immunotherapeutic strategy for both FLT3- mutant AML and KMT2A-rearranged ALL which is poised for further investigation and clinical translation.