GFRα4 CAR T Cells in MTC Patients

Study Overview
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Brief Summary
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This is an open-label phase 1 study to assess the safety and feasibility of autologous T cells expressing a single-chain scFv targeting GFRα4 with tandem TCR/CD3ζ and 4-1BB (TCRζ/4-1BB) co-stimulatory domains (referred to as CART-GFRa4 cells) in patients with incurable medullary thyroid cancer (MTC).

Official Title
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Phase I Trial of GFRα4 CAR T Cells in Adult Patients With Recurrent or Metastatic Medullary Thyroid Cancer

Conditions
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Metastatic Medullary Thyroid Cancer

Intervention / Treatment
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* Drug: single dose of CART-GFRa4 cells
* Drug: Fludarabine
* Drug: Cyclophosphamide


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Signed, written informed consent Male or female age ≥ 18 years Histologically or cytologically confirmed diagnosis of medullary thyroid cancer (MTC). Incurable recurrent/metastatic disease that is progressive after at least 1 prior tyrosine kinase inhibitor (TKI) containing regimen, or the patient was intolerant of or declined such therapy. Adequate organ function defined as: Serum creatinine ≤ 2.5 mg/dl or estimated creatinine clearance ≥ 30 ml/min and not on dialysis. AST ≤ 5x upper limit of normal range and total bilirubin ≤ 2.0 mg/dl; except for patients in whom hyperbilirubinemia is attributed to Gilbert's syndrome. Left Ventricular Ejection Fraction (LVEF) ≥ 45% confirmed by ECHO/MUGA Must have a minimum level of pulmonary reserve defined as ≤ Grade 1 dyspnea and pulse oxygen > 92% on room air ECOG Performance Status that is either 0 or 1. Toxicities from prior therapies must have recovered to grade ≤ 2 according to the CTCAE 5.0 criteria or to the patient's prior baseline. Patients must have evaluable disease as defined by RECIST 1.1. Subjects of reproductive potential must agree to use acceptable birth control methods. Exclusion Criteria: Evidence of active hepatitis B or hepatitis C infection. Any other active, uncontrolled infection. Any prior history of moderate to severe (Grade 2 or higher) pneumonitis. Subjects with chronic kidney disease with Grade 2 or higher renal impairment (eGFR or CrCl 59-30 ml/min/1.73 m2). Class III/IV cardiovascular disability according to the New York Heart Association Classification. Clinically apparent arrhythmia or arrhythmias that are not stable on medical management within two weeks of physician-investigator confirmation of eligibility. Planned concurrent treatment with systemic high dose corticosteroids. Patients may be on a stable low dose of steroids (≤10mg equivalent of prednisone). Use of inhaled steroids is allowable. Corticosteroid treatment as anti-emetic prophylaxis on the day of lymphodepleting chemotherapy administration is allowed per institutional practice. Any moderate to severe skin rash or allergies requiring systemic treatment. Receipt of immune checkpoint inhibitors within 2 months prior to physician-investigator confirmation of eligibility - Retired with Protocol Version 3. Pregnant or nursing (lactating) women. Active autoimmune disease requiring systemic immunosuppressive treatment equivalent to ≥ 10mg daily of prednisone. Patients with autoimmune neurological diseases (such as MS or Parkinson's) will be excluded. Have any history of prior or active central nervous system (CNS) involvement (e.g., leptomeningeal disease, parenchymal masses) with MTC. Screening for this (e.g., with lumbar puncture and/or brain MRI) is not required unless suspicious symptoms and/or radiographic findings are present. Subjects with calvarial metastatic disease that extends intracranially and involves the dura will be excluded, even if CSF is negative for MTC. Known seizure disorder or history of prior seizures requiring medication. History of allergy or hypersensitivity to study product excipients (human serum albumin, DMSO, and Dextran 40).

Ages Eligible for Study
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Minimum Age: 18 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: Health Services Research
Allocation: Non-Randomized
Intervention Model: Sequential Assignment
Interventional Model Description: The is a Phase I dose finding study to determine the safety of CART-GFRa4 cells. Dose escalation and determination of maximum tolerated dose (MTD) will be based on the standard 3+3 design to explore 3 possible dose levels.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Cohort 1: single dose of 5x10^7 CART-GFRa4 cells via intravenous infusion<br> | Drug: single dose of CART-GFRa4 cells<br>* Intravenous infusion of lentiviral transduced autologous T cells that have been engineered to express an extracellular single chain antibody (scFv) with specificity towards GFRa4 with fludarabine and cyclophosphamide.<br>Drug: Fludarabine<br>* Lyphodepletion<br>Drug: Cyclophosphamide<br>* Lyphodepletion<br>|
| Experimental: Cohort -1: single dose of 2x10^7 CART-GFRa4 cells via intravenous infusion<br> | Drug: single dose of CART-GFRa4 cells<br>* Intravenous infusion of lentiviral transduced autologous T cells that have been engineered to express an extracellular single chain antibody (scFv) with specificity towards GFRa4 with fludarabine and cyclophosphamide.<br>Drug: Fludarabine<br>* Lyphodepletion<br>Drug: Cyclophosphamide<br>* Lyphodepletion<br>|
| Experimental: Cohort 2: single dose of 1x10^8 CART-GFRa4 cells via intravenous infusion<br> | Drug: single dose of CART-GFRa4 cells<br>* Intravenous infusion of lentiviral transduced autologous T cells that have been engineered to express an extracellular single chain antibody (scFv) with specificity towards GFRa4 with fludarabine and cyclophosphamide.<br>Drug: Fludarabine<br>* Lyphodepletion<br>Drug: Cyclophosphamide<br>* Lyphodepletion<br>|
| Experimental: Cohort 3: single fixed dose of 3x10^8 CART-GFRa4 cells via intravenous infusion<br> | Drug: single dose of CART-GFRa4 cells<br>* Intravenous infusion of lentiviral transduced autologous T cells that have been engineered to express an extracellular single chain antibody (scFv) with specificity towards GFRa4 with fludarabine and cyclophosphamide.<br>Drug: Fludarabine<br>* Lyphodepletion<br>Drug: Cyclophosphamide<br>* Lyphodepletion<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of Treatment-Emergent Adverse Events as assessed by CTCAE v5.0. |  | 15 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of manufacturing products that meet release criteria. |  | 3 months | 
| Number of subjects who have a response |  | 12 months | 
| Best Overall Response (BOR) |  | 12 months | 
| Duration of Response (DOR) |  | 12 months | 
| Overall survival (OS) |  | 12 months | 
| Progression-free survival (PFS) |  | 12 months |