Phase I/II Open-label Study Evaluating The Safety And Efficacy of Concomitant Administration of Anti-CD19 CAR T-cell Therapy and Lenalidomide in Refractory/Relapsed Chronic Lymphocytic Leukemia Patients.

Inclusion Criteria:

• Documented CD19+ CLL or SLL

• Patients must have failed at least 1 prior regimen

• Patients must be currently receiving ibrutinib for at least 3 months prior toenrollment in the study and:

• Not experiencing any ≥ grade 2 non-hematologic ibrutinib-related toxicity

• ECOG Performance status 0 or 1

• 18 years of age and older

• Adequate organ system function including:

Creatinine < 1.6 mg/dl ALT/AST < 3x upper limit of normal Total Bilirubin <2.0 mg/dl with the exception of patients with Gilbert syndrome; patients with Gilbert syndrome may be included if their total bilirubin is ≥ 3.0 x ULN and direct bilirubin ≤ 1.5 x ULN.

• Have no active GVHD and require no immunosuppression

• Are more than 6 months from transplant

• No contraindications for leukapheresis

• Left Ventricular Ejection fraction >50%

• Gives informed consent

Exclusion Criteria:

• CLL patients with known or suspected transformed disease (i.e. Richter'stransformation).

• Pregnant or lactating women.

• Uncontrolled active infection.

• Active hepatitis B or hepatitis C infection.

• Concurrent use of systemic steroids or chronic use of immunosuppressant medications.

• Any uncontrolled active medical disorder

• HIV infection.

• Patients with active CNS involvement with malignancy.

• Class III/IV cardiovascular disability according to the New York Heart AssociationClassification.

• Subjects with clinically apparent arrhythmia or arrhythmias who are not stable