Study of CAR T-cell Therapy in Acute Myeloid Leukemia and Multiple Myeloma

Study Overview
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Brief Summary
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The purpose of this first-in-man Phase I-IIa study is to evaluate the safety and antitumor activity of autologous CD44v6 CAR T-cells in patients with acute myeloid leukemia (AML) and multiple myeloma (MM).

Detailed Description
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The study is a seamless Phase I/IIa, open-label, multicenter clinical trial that combines Phase I dose escalation based on toxicity with Phase IIa dose expansion based on antitumor activity. Considering the first in human nature of this clinical study, the Bayesian Optimal Interval Design (BOIN) has been chosen to minimize any risks of exposure to the novel CD44v6 CAR T-cells during dose escalation. The study population is made up of patients with relapsed/refractory AML or MM expressing CD44v6. The medicinal product under investigation (MLM-CAR44.1 T-cells) is patient specific as it is prepared starting from lymphocytes of the patient collected through lymphocyte apheresis. These autologous T-cells are expanded in vitro in large numbers and genetically modified to express the CAR CD44v6ΔNL gene and thus acquire antitumor functions. As a safety feature, the MLM-CAR44.1 T-cells are genetically modified to also express the HSV-TK Mut2 gene (suicide gene), which can be selectively activated in case of severe toxicity through the administration of ganciclovir (GCV), leading to the death of proliferating CAR T-cells. The aim of this study is to assess the safety, antitumor activity and feasibility of CD44v6 CAR T cell immunotherapy in AML and MM.

Official Title
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A Phase I-IIa Trial to Assess the Safety and Antitumor Activity of Autologous CD44v6 CAR T-cells in Acute Myeloid Leukemia and Multiple Myeloma Expressing CD44v6

Conditions
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Acute Myeloid Leukemia, Multiple Myeloma

Intervention / Treatment
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* Drug: MLM-CAR44.1 T-cells at day 0 Single intravenous infusion


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients must meet all the following inclusion criteria to be eligible for the study. Written informed consent before any study-related procedure. Adults and children: Adults 18 to 75 (65) years old with AML or MM. Children 1 to 17 years old with AML, only in Phase IIa. Confirmed diagnosis of AML or MM as follows: AML: Primary or secondary AML (any subtype except acute promyelocytic leukemia) according to World Health Organization (WHO) classification. MM with measurable disease as defined by the International Myeloma Working Group (IMWG). Patients with relapse or refractory disease: AML patients must be unlikely to benefit from cytotoxic chemotherapy as follows: Leukemia refractory to at least 2 induction attempts. Leukemia in relapse within 1 year following complete response (CR) after at least 2 induction attempts. High-risk leukemia in adults according to 2017 European LeukemiaNet (ELN) in first relapse after a hypomethylating agent or a cycle containing cytarabine at a dose ≥ 1g/sqm a day (e.g. FLAG-IDA), except for FLT3-mutated AML. High-risk leukemia in children as defined by the Italian Association of Pediatric Hematology and Oncology (AIEOP). Patients with MM must have a relapse or refractory disease after at least 4 different prior treatments in 3 treatment lines, or 4 treatments in 2 treatment lines in case of early relapsing patients (relapse in less than 1.5 years). Treatments include: Proteasome inhibitor High-dose alkylating agent if patients less than 70 years old Immunomodulatory drug (IMID) A monoclonal antibody (i.e. anti CD38 monoclonal antibody) Positive CD44v6 expression on tumor cells by flow cytometry. Eastern Cooperative Oncology Group (ECOG) performance status 0-2. Life expectancy of at least 12 weeks. Adequate organ function (hepatic, cardiac, pulmonary). Recovery from toxicities of clinical consequence attributed to previous chemotherapy to CTCAE v5.0 Grade 1 (i.e., certain toxicities such as alopecia will not be considered in this category). Ability to comply with study procedures, including hospitalization and protocol-specified acquisition of blood and/or bone marrow specimens. Willing to be followed up long term, i.e. a 15-year follow up as required by health authorities for cell and gene therapy products. Women of childbearing potential must test negative for pregnancy at enrolment and during the study. Exclusion Criteria: At screening: patients must meet none of the following exclusion criteria to be eligible for the study: History of or candidate for allogeneic stem cell transplantation. Cardiovascular, pulmonary, renal, and hepatic functions that in the judgment of the investigator are insufficient for the patient to undergo investigational CAR T-cell therapy. Any history of or suspected current autoimmune disorders (apart from vitiligo, resolved childhood atopic dermatitis, Graves' disease clinically controlled). History of rheumatologic disorders requiring specific treatment at any time in the patient's medical history.

Ages Eligible for Study
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Minimum Age: 1 Year
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: MLM-CAR44.1 T-cells infusion<br>PHASE I: i.v. single dose of MLM-CAR44.1 T-cells: 0.5 x 10E6/Kg or 1 x 10E6/Kg or 2 x10E6/Kg according to the BOIN design. PHASE IIa: i.v. single dose of MLM-CAR44.1 T-cells corresponding to the maximum tolerated dose (MTD). Phase I and IIa Pre-treatment: lymphodepleting chemotherapy with cyclophosphamide (500 mg/m2) and fludarabine (30 mg/m2) daily from day -5 to day -3 | Drug: MLM-CAR44.1 T-cells at day 0 Single intravenous infusion<br>* Lymphodepleting chemotherapy with cyclophosphamide (500 mg/m2) and fludarabine (30 mg/m2) daily from day -5 to day -3.<br>* Other names: CAR-T cells;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Phase I: Maximum Tolerated Dose (MTD) and the Recommended Phase IIa Dose of MLM-CAR44.1 T-cells in AML and MM | MTD established through BOIN design and the dose-limiting toxicities (DLTs) occurring following CAR T-cell infusion. | Within 30 days following CAR T-cell infusion, assessed as day 0 | 
| Phase I: Overall Safety of Treatment With MLM-CAR44.1 T-cells | Safety will be evaluated by analyzing the type, frequency and severity of adverse events (AE) and by monitoring for systemic reactions (fever, tachycardia, nausea and vomiting, joint pain, skin rash). Overall, 3 study emergent serious adverse events (SAEs) were reported in patients treated with MLM-CAR44.1 T-cells. | For 30 days following CAR T-cell infusion, assessed as day 0. | 
| Phase I: Absence of Replication Competent Retrovirus (RCR) in Blood Specimens: 3 Months Post-infusion | The absence of replication competent retrovirus (RCR) in blood specimens: 3 months post-infusion will be monitored by DNA PCR for the Galv gene. RCR search was conducted centrally using a quantitative molecular test, (real time quantitative PCR, q-PCR analysis) determining the absence of RCR by DNA PCR for the Galv and gag-pol genes on genomic DNA from patient's peripheral blood lymphocytes. The objective of this q-PCR analysis is to exclude the presence of RCR originated by recombination with PG13 packaging cell sequences by detecting the Galv and gag-pol transcripts in the transduced cells. The absence of the Galv and gag-pol transcripts can exclude the presence of an RCR, while its presence is not sufficient to indicate the presence of an RCR, and in this case further analysis is required. | 3 months after infusion (assessed as day 0) | 
| Phase I: Absence of Replication Competent Retrovirus (RCR) in Blood Specimens: 6 Months Post-infusion | The absence of replication competent retrovirus (RCR) in blood specimens will be monitored by DNA PCR for the Galv gene. RCR search was conducted centrally using a quantitative molecular test, (real time quantitative PCR, q-PCR analysis) determining the absence of RCR by DNA PCR for the Galv and gag-pol genes on genomic DNA from patient's peripheral blood lymphocytes. The objective of this q-PCR analysis is to exclude the presence of RCR originated by recombination with PG13 packaging cell sequences by detecting the Galv and gag-pol transcripts in the transduced cells. The absence of the Galv and gag-pol transcripts can exclude the presence of an RCR, while its presence is not sufficient to indicate the presence of an RCR, and in this case further analysis is required | 6 months after infusion (assessed as day 0) | 
| Phase I: Absence of Replication Competent Retrovirus (RCR) in Blood Specimens: 12 Months Post-infusion | The absence of replication competent retrovirus (RCR) in blood specimens will be monitored by DNA PCR for the Galv gene. | 12 months after infusion (assessed as day 0) | 
| Phase I: Absence of Replication Competent Retrovirus (RCR) in Blood Specimens: 24 Months Post-infusion | The absence of replication competent retrovirus (RCR) in blood specimens will be monitored by DNA PCR for the Galv gene. | 24 months after infusion (assessed as day 0) | 
| Phase IIa: Hematological Disease Response to MLM-CAR44.1 T-cells in AML. | The hematologic disease response will be classified according to ELN criteria. | 2 months after MLM-CAR44.1 T-cell infusion, assessed as day 0 | 
| Phase IIa: Hematological Disease Response to MLM-CAR44.1 T-cells in MM | The hematologic disease response will be classified according to IMWG criteria | 3 months after T-cell infusion, assessed as day 0 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Phase I: Hematologic Disease Response to MLM-CAR44.1 T-cells in AML | The hematologic disease response will be classified with the following response criteria: complete response (CR), incomplete response (CRi) and partial response (PR) according to ELN criteria. | 1 and 2 months following T-cell infusion, assessed as day 0 | 
| Phase I: Hematologic Disease Response to MLM-CAR44.1 T-cells in MM | Hematologic disease response evaluated at Day 28 following CART-cell infusion, as overall response rate (ORR), stringent complete response (sCR), CR, very good partial response (VGPR) and partial response (PR). | 1 and 3 months following T-cell infusion, assessed as day 0 | 
| Phase I: The Levels of Circulating MLM-CAR44.1 T-cells in Blood Samples | The levels will be evaluated by flow cytometry and qPCR (in vivo pharmacokinetic profile). | At day 7, 14, 21, 28, 60, 90, 180 from infusion, assessed as day 0 | 
| Phase I: The Percentage of Patients for Whom Activation of Suicide Gene Was Needed | Suicide gene activation and elimination of transduced cells will be established through administration of ganciclovir in case of cytokine-release syndrome (CRS) and other MLM-CAR44.1 T-cell related toxicities. | At day 7, 14, 21, 28, 60, 90, 180 from infusion, assessed as day 0 | 
| Phase IIa: Hematologic Disease Response in AML | The hematologic disease response will be classified with the following response criteria: complete response (CR), incomplete response (CRi) and partial response (PR) according to ELN criteria. | 1, 2 and 6 months after MLM-CAR44.1 T-cell infusion, assessed as day 0. | 
| Phase IIa: Hematologic Disease Response in MM | The hematologic disease response will be defined based on the overall response rate (ORR): stringent complete response (sCR), complete response (CR), very good partial response (VGPR), and partial response (PR) according to IMWG criteria | 1, 2 and 6 months after T-cell infusion, assessed as day 0 | 
| Phase IIa: Overall Survival (OS) | Overall Survival (OS) is defined as the time from the date of MLM-CAR44.1 T-cell infusion to the date of last follow-up or death due to any cause, whichever occurs first. One patients out of the 2 treated was still alive at the date of the early study termination. One patient died after EURE-CART-1 cell infusion, at day 121, for disease progression. | At the date of the early study termination |