T-cells Expressing an Anti-SLAMF7 CAR for Treating Multiple Myeloma

Background:

• Multiple myeloma (MM) is a nearly always incurable malignancy of plasma cells.
• T cells can be genetically modified to express chimeric antigen receptors (CARs) that target malignancy-associated antigens.
• Signaling lymphocytic activation molecule F7 (SLAM7) is highly and uniformly expressed on MM cells but is absent on normal tissues except for some leukocytes, including a subset of cluster of differentiation 8 (CD8)+ T cells, natural killer (NK) cells, B cells, plasma cells and monocytes.
• We have constructed a novel anti-SLAMF7 CAR that can specifically recognize SLAMF7- expressing target cells and eradicate SLAMF7-expressing tumors in mice.
• This protocol will test genetic modification of autologous T cells with genes encoding an inducible caspase 9 (IC9) cell-suicide system plus the anti-SLAMF7 CAR.
• Administration of the dimerizer drug Rimiducid (AP1903) is necessary to activate the inducible caspase 9 (IC9) suicide gene and eliminate CAR T cells.
• In this protocol, the suicide gene system will be used to eliminate CAR-expressing T cells in case of severe toxicities caused by the CAR T cells.
• Possible toxicities include cytokine-associated toxicities such as hypotension, and neurological toxicities. Elimination of NK cells and normal plasma cells could make patients more susceptible to infections. Unknown toxicities are also possible.

Objectives:

Primary

• Determine the safety, feasibility of administering T cells expressing an anti-SLAMF7 CAR plus IC9 cell-suicide system to patients with MM.

Eligibility:

• Greater than or equal to 18 years of age and less than or equal to age 73.
• Patients must have measurable MM defined as a serum M-protein >=0.6 g/dL or a urine M-protein >=200 mg/24 hours or an involved serum free light chain (FLC) level >=10 mg/dL (provided FLC ratio is abnormal) or a biopsy-proven plasmacytoma of 1.5 cm or more in largest dimension, or greater than or equal to 30% bone marrow plasma cells.
• Patients must have previously received at least 3 different treatment regimens for MM.
• Patients must have prior exposure to an immunomodulatory drug (IMiD) such as lenalidomide, and a proteasome inhibitor
• Patients must have a creatinine level of less than or equal to 1.5 mg/dL
• Patients must have a cardiac ejection fraction >= 50%.
• An Eastern Cooperative Oncology Group (ECOG) performance status of 0-2 is required.
• Patients on any anticoagulant medications except aspirin are not eligible.
• No active infections are allowed.
• Absolute neutrophil count >= 1000/microL, platelet count >= 55,000/microL, hemoglobin >= 8g/dL
• Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) less than or equal to 2.5-fold higher than the upper limit of normal.
• At least 14 days must elapse between the time of any prior systemic treatment (including corticosteroids) and the required leukapheresis.
• At least 14 days must elapse between the time of any prior systemic treatment and initiation of protocol treatment. Systemic therapy includes corticosteroids at a dose equivalent to more than 5 mg of prednisone.
• Bone marrow plasma cells must make up less than or equal to 50% of total bone marrow cells less than or equal to 24 days prior to the start of protocol treatment.
• The patient's MM will need to be assessed for SLAMF7 expression by flow cytometry or immunohistochemistry performed at the National Institutes of Health (NIH). The myeloma must express SLAMF7. If unstained, paraffin-embedded bone marrow or plasmacytoma sections are available from prior biopsies, these can be used to determine SLAMF7 expression by immunohistochemistry; otherwise patients will need to come to the NIH for a bone marrow biopsy or other biopsy of a plasmacytoma to determine SLAMF7 expression. The sample for SLAMF7 expression can come from a biopsy obtained at any time before enrollment.

Design:

• This is a phase I dose-escalation trial
• Patients will undergo leukapheresis, and T cells will be modified to express the IC9-anti-SLAMF7 CAR construct.
• The chemotherapy conditioning regimen is cyclophosphamide 300 mg/m^2 daily for 3 days and fludarabine 30 mg/m^2 daily for 3 days. The intent of chemotherapy is to enhance CAR T-cell activity.
• After the chemotherapy ends, the patients will have two days with no treatments and then receive an infusion of CAR T cells.
• The initial dose level will be 0.66x10^6 Anti-SLAMF7-CAR + T cells/kg of recipient bodyweight.
• The cell dose administered will be escalated for up to 4 doses until a maximum tolerated dose is determined.
• Following the T-cell infusion, there will be a mandatory 9-day minimum inpatient hospitalization to monitor for toxicity.
• Outpatient follow-up is planned for 2 weeks, and 1, 2, 3, 4, 6, 9, and 12 months after the CAR T-cell infusion. Afterwards, follow-up will be every six months up to at least 3 years after infusion.

• INCLUSION CRITERIA - MULTIPLE MYELOMA:
• Signaling lymphocytic activation molecule F7 (SLAMF7) expression must be detected on malignant plasma cells from either bone marrow or a plasmacytoma by flow cytometry or immunohistochemistry. A specific quantitative level of SLAMF7 expression for eligibility is not specified, but patients with multiple myeloma cells that are negative for SLAMF7 by flow cytometry and immunohistochemistry will not be enrolled. These assays must be performed at the National Institutes of Health (NIH). It is not required that the specimen used for SLAMF7 determination comes from a sample that was obtained after the patient's most recent treatment. If paraffin embedded unstained samples of bone marrow involved with MM or a plasmacytoma are available, these can be shipped to the NIH for SLAMF7 staining, otherwise new biopsies will need to be performed for determination of SLAMF7 expression.
• SLAMF7 expression will need to be documented on the majority of malignant plasma cells by flow cytometry at the NIH at some time after the original chimeric antigen receptor (CAR)-SLAMF7 T-cell infusion in all patients undergoing a second CAR-SLAMF7 T-cell infusion on this clinical trial.
• Bone marrow plasma cells must make up less than or equal to 50% of total bone marrow cells based on a bone marrow biopsy performed within 24 days of the start of protocol treatment.
• Patients must have received at least 3 different prior treatment regimens for multiple myeloma (MM)
• Must have prior exposure to an immunomodulatory drug (IMiD) such as lenalidomide and a proteasome inhibitor
• Patients must have measurable MM as defined by at least one of the criteria below.

• Serum M-protein greater or equal to 0.6 g/dL.
• Urine M-protein greater or equal to 200 mg/24 h.
• Serum free light chain (FLC) assay: involved FLC level greater or equal to 10 mg/dL (100 mg/L) provided serum FLC ratio is abnormal.
• A biopsy-proven plasmacytoma at least 1.5 cm in largest dimension
• Bone marrow core biopsy with 30% or more plasma cells

Inclusion criteria

- OTHER:

• Greater than or equal to 18 years of age and less than or equal to age 73.
• Able to understand and sign the Informed Consent Document.
• Clinical performance status of Eastern Cooperative Oncology Group (ECOG) 0-2
• Patients of both sexes must be willing to practice birth control from the time of enrollment on this study and for four months after last day of receiving protocol treatment.
• Seronegative for human immunodeficiency virus (HIV) antibody. (The experimental treatment being evaluated in this protocol depends on an intact immune system. Patients who are HIV seropositive can have decreased immune-competence and thus are less responsive to the experimental treatment and more susceptible to its toxicities.)
• A patient with a negative blood polymerase chain reaction (PCR) test for hepatitis B deoxyribonucleic (DNA) test can be enrolled. If hepatitis B DNA (PCR) testing is not available, patients with a negative hepatitis B surface antigen and negative hepatitis B core antibody can be enrolled.
• Patients must be tested for the presence of Hepatitis C antigen by PCR and be hepatitis C virus (HCV) ribonucleic acid (RNA) negative in order to be eligible. Only if Hepatitis C PCR testing is not available in a timely manner, patients who are Hepatitis C antibody-negative can be enrolled.
• Absolute neutrophil count greater than or equal to 1000/mm^3 without the support of filgrastim or other growth factors within the previous 10 days.
• Platelet count greater than or equal to 55,000/mm^3 without transfusion support in the past 14 days.
• Hemoglobin greater than or equal to 8.0 g/dL.
• Less than 5% plasma cells in the peripheral blood leukocytes
• Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) less or equal to 2.5 times the upper limit of the institutional normal.
• Serum creatinine less than or equal to 1.5 mg/dL.
• Total bilirubin less than or equal to 2.0 mg/dL, except in patients with Gilbert's Syndrome who must have a total bilirubin less than 3.0 mg/dL.
• At least 14 days must have elapsed since any prior systemic therapy at the time the patient starts the cyclophosphamide and fludarabine conditioning regimen, and patients toxicities must have recovered to a grade 1 or less (except for toxicities such as alopecia or vitiligo or cytopenias).
• Because this protocol requires collection of autologous blood cells by leukapheresis in order to prepare CAR-SLAMF7 T cells, systemic anti-myeloma therapy including systemic corticosteroid steroid therapy of greater than 5 mg/day of prednisone or equivalent dose of another corticosteroid are not allowed within 14 days prior to the required leukapheresis.
• Normal cardiac ejection fraction (greater than or equal to 50% by echocardiography) and no evidence of hemodynamically significant pericardial effusion as determined by an echocardiogram.
• For patients with past participation in gene-therapy, cryopreserved peripheral blood mononuclear cells (PBMC) that have not been genetically engineered must be available.
• Patients receiving prior gene therapy outside of NIH will not be eligible. Patients who previously received CAR T-cell therapy at the National Cancer Institute (NCI) will be potentially eligible.

Exclusion criteria

• Patients who are receiving any other investigational agents.
• Patients on any anticoagulants except aspirin
• Patients that require urgent therapy due to tumor mass effects or spinal cord compression.
• Patients that have active hemolytic anemia.
• Patients with second malignancies in addition to multiple myeloma are not eligible if the second malignancy has required treatment within the past 3 years or is not in complete remission. There are two exceptions to this criterion: successfully treated non-metastatic basal cell or squamous cell skin carcinoma.
• Women of child-bearing potential who are pregnant or breastfeeding because of the potentially dangerous effects of the preparative chemotherapy on the fetus or infant. Women of child bearing potential cannot have a positive pregnancy test. Women of childbearing potential are defined as all women except women who are post-menopausal or who have had a hysterectomy. Postmenopausal will be defined as women over the age of 55 who have not had a menstrual period in at least 1 year.
• Active systemic infections (defined as infections causing fevers or requiring anti-microbial treatment), active coagulation disorders or other major uncontrolled illnesses of the cardiovascular, respiratory, endocrine, renal, gastrointestinal, genitourinary, neurologic, psychiatric, or immune system, history of myocardial infarction, active cardiac arrhythmias, active obstructive or restrictive pulmonary disease.
• Any form of primary immunodeficiency (such as Severe Combined Immunodeficiency Disease).
• Systemic corticosteroid steroid therapy of greater than 5 mg/day of prednisone or equivalent dose of another corticosteroid (prednisone, dexamethasone, etc.) is not allowed within 14 days prior to either the required leukapheresis or within 14 days prior to CAR Tcell infusion (and at any time after the CAR T-cell infusion unless approved by the Principal Investigator or an Associate Investigator).
• History of severe immediate hypersensitivity reaction to any of the agents used in this study.
• Patient unwilling to undergo intensive care unit treatment including mechanical ventilation, cardiopulmonary resuscitation, vasoactive drugs, and hemodialysis.
• History of allogeneic stem cell transplantation
• Patients with current spinal cord compression (without intradural myeloma involvement.
• Patients who have a history (or current evidence) of cerebrospinal fluid multiple myeloma, or intradural central nervous system masses.
• Patients with active autoimmune skin diseases such as psoriasis or other active autoimmune diseases such as rheumatoid arthritis.
• Patients must not have required supplemental oxygen within the past month unless it was for a resolved infection.