This phase I trial studies the side effects and best dose of CS1-chimeric antigen receptor
(CAR) T therapy after chemotherapy in treating patients who have CS1 positive multiple
myeloma that has come back or does not respond to treatment. Immune cells can be engineered
to kill multiple myeloma cells by inserting a piece of deoxyribonucleic acid (DNA) into the
immune cells using a lentiviral vector such as CS1, that allows them to recognize multiple
myeloma cells. These engineered immune cells, CS1-CAR T cells, may kill multiple myeloma
I. To evaluate the safety and tolerability of intravenous (i.v.) delivered autologous CS1?CAR
T cells for research participants with CS1+ recurrent/refractory multiple myeloma (MM).
I. Evaluate the response rates at days 28, 100, and 180 post CAR T cell infusion.
II. Measure the persistence of CS1?CAR T cells in blood and marrow. III. Measure phenotype
and anti?tumor functionality of CS1?CAR T cells in marrow and blood.
IV. Measure the levels of cytokines in blood and marrow, and soluble CS?1 in blood post
infusion as a surrogate indicator of CAR T cell activity.
V. Evaluate CS?1 expression on MM cancer cells before, during and at progressive disease (PD)
to determine antigenic loss.
I. Describe the percentage of MM cells that express CS-1 surface marker before, during and at
OUTLINE: This is a dose-escalation study of CS1-CAR T cells.
Patients undergo leukapheresis over 2-4 hours. Beginning 3-4 weeks, patients receive
cyclophosphamide intravenously (IV) on days -4 and/or -3 or fludarabine IV and
cyclophosphamide IV on days -5 to -3. Patients then undergo CS1-CAR T therapy over 10-15
minutes on day 0.
After completion of study treatment, patients are followed up at 1 day, at least every 2 days
for up to a minimum of 14 days, weekly for 1 month, monthly for 1 year, then periodically for
up to 15 years.
- Documented informed consent of the participant and/or legally authorized
- Assent, when appropriate, will be obtained per institutional guidelines.
- Karnofsky Performance Status (KPS) of >= 70%.
- Life expectancy >= 16 weeks.
- Participant must have a confirmed diagnosis of active MM as defined by the
International Myeloma Working Group (IMWG) criteria.
- Participant must have a confirmed CS1+ MM as evaluated by City of Hope (COH) Pathology
- Participant must have measurable disease defined as meeting at least one of the
- Serum M?protein >= 0.5 g/dL.
- Urine M?protein >= 200 mg/24 hour.
- Involved serum free light chain (sFLC) level >= 10 mg/dL with abnormal
- Measurable biopsy?proven plasmacytomas (>= 1 lesion that has a single diameter >=
- Bone marrow plasma cells >= 30%.
- Participant must have relapsed or refractory disease after all 3 prior treatment
regimens with the following requirements:
- Participant must have received prior treatment with an immunomodulatory agent.
- Participant must have received prior treatment with a proteasome inhibitor.
- Participant must have received prior treatment with an anti?CD38 antibody.
- Participants must be refractory to last line of therapy prior to study enrollment
(refractory myeloma is defined as disease that is nonresponsive, progression on
treatment, or shows progression within 60 days after the last prior line of
- Participants who were not candidates to receive one or more of the above
treatments are eligible; however, the reason must be clearly documented in the
case report form.
- Note: induction chemotherapy, autologous stem-cell transplantation (ASCT), and
maintenance therapy should be considered as 1 "regimen."
- Additionally, if a participation underwent autologous transplant he/she be >= 90 days
from transplant at the time of enrollment.
- Total serum bilirubin =< 2.0 mg/dL.
- Participants with Gilbert syndrome may be included if their total bilirubin is =< 3.0.
- Aspartate aminotransferase (AST) < 2.5 x upper limit of normal (ULN).
- Alanine aminotransferase (ALT) < 2.5 x ULN.
- Serum creatinine =< 2.5 x ULN or estimated creatinine clearance of >= 40 mL/min per
the Cockcroft?Gault formula, and the participant is not on hemodialysis.
- Absolute neutrophil count >= 1000/uL. Transfusions and growth factors must not be used
to meet these requirements at initial screening.
- Hemoglobin (Hb) >= 8 g/dl. Transfusions and growth factors must not be used to meet
these requirements at initial screening.
- Platelet count >= 50,000/uL (>= 30,000/uL if bone marrow plasma cells are >= 50% of
cellularity). Transfusions and growth factors must not be used to meet these
requirements at initial screening.
- Left ventricular ejection fraction >= 45% within 8 weeks before enrollment.
- Oxygen (O2) saturation >= 92%.
- Women of childbearing potential (WOCBP): Negative urine or serum pregnancy test.
- If the urine test is positive or cannot be confirmed as negative, a serum pregnancy
test will be required.
- Agreement by females and males of childbearing potential to use an effective method of
birth control or abstain from heterosexual activity for the course of the study
through at least 3 months after the last dose of protocol therapy.
- Childbearing potential defined as not being surgically sterilized (men and women)
or have not been free from menses for > 1 year (women only).
- Prior allogeneic stem cell transplantation.
- Autologous transplantation =< 90 days of enrollment.
- Growth factors within 14 days of enrollment.
- Platelet transfusions within 7 days of enrollment.
- Participants receiving any other investigational agents, or concurrent biological,
chemotherapy, or radiation therapy.
- Participants with known additional malignancy that is progressing or required active
treatment within the last 2 years. Exceptions include basal cell carcinoma of the
skin, squamous cell carcinoma of the skin, or in situ cervical cancer that has
undergone potentially curative therapy.
- Participants with toxicities from prior therapies, with the exception of peripheral
neuropathy attributable to bortezomib, that have not recovered to grade =< 2 according
to the Common Terminology Criteria for Adverse Events (CTCAE) 5.0 criteria or to the
subject's prior baseline.
- Participants with known active hepatitis B or C infection; research participants who
are human immunodeficiency virus (HIV) positive based on testing performed within 4
weeks of enrollment; research participants with any signs or symptoms of active
infection, positive blood cultures or radiological evidence of infections.
- Participants with active auto?immune disease, including connective tissue disease,
sarcoidosis, multiple sclerosis, inflammatory bowel disease or have a history of
severe (as judged by the principal investigator) autoimmune disease that will require
prolonged immunosuppressive therapy.
- Have New York Heart Association (NYHA) Class III or IV heart failure, unstable angina,
or a history of recent (within 6 months) myocardial infarction.
- Participants with a history or presence of clinically relevant central nervous system
(CNS) pathology such as uncontrolled seizure disorder, stroke, severe brain injuries,
dementia, cerebellar disease or psychosis.
- Participants with known active central nervous system (CNS) involvement by malignancy.
Subjects with prior CNS disease that has been effectively treated will be eligible if
treatment was completed at least 3 months prior to enrollment with no evidence of
symptomatic disease and stable abnormalities on repeat imaging.
- Participants with plasma cell leukemia (PCL) or symptomatic amyloidosis. However,
participants with a prior history of PCL are not excluded.
- Participants with any known contraindications to leukapheresis, cyclophosphamide,
fludarabine, cetuximab or tocilizumab.
- Dependence on corticosteroids.
- Defined as doses of corticosteroids of greater than or equal to 10 mg/day of
prednisone or equivalent doses of other corticosteroids.
- Note: Topical and inhaled corticosteroids in standard doses and physiologic
replacement for subjects with adrenal insufficiency are allowed.
- Participants with inadequate venous access for leukapheresis, and who are either
unable to or unwilling to have a supportive line (temporary or other) placed for the
- Females only: Pregnant or breastfeeding.
- Any other condition that would, in the Investigator?s judgment, contraindicate the
subject?s participation in the clinical study due to safety concerns with clinical
- Prospective subjects who, in the opinion of the investigator, may not be able to
comply with all study procedures (including compliance issues related to