A Feasibility and Safety Study of Dual Specificity CD19 and CD22 CAR-T Cell Immunotherapy for CD19+CD22+ Leukemia

Inclusion Criteria: * First 2 subjects: male and female subjects age ≥18 and \< 27 years (as of 2/16/18 the first 2 subjects were enrolled and treated); subsequent subjects \<31 years. * Diagnosis of CD19+22+ leukemia * Disease status: * If post allogeneic HCT: Confirmed CD19+CD22+ leukemia recurrence defined as at least 0.01% disease following allogeneic HCT * If relapse/refractory status with no prior history of allogeneic HCT, one of the following: * Second or greater marrow relapse, with or without extramedullary disease * First marrow relapse at end of first month or re-induction with marrow having at least 0.01 % blasts by morphology and/or MPF * Primary refractory as defined as greater than 5% blasts by multi-parameter flow after at least 2 separate induction regimens. * Subject has indication for HCT but has been deemed ineligible, inclusive of persistent MRD prior to HCT * Asymptomatic from CNS involvement, if present, and in the opinion of the Principal Investigator with a reasonable expectation that disease burden can be controlled in the interval between enrollment and T-cell infusion. Subjects with significant neurologic deterioration will not be eligible for T-cell infusion until stabilized. * Free from active GVHD and off immunosuppressive GVHD therapy for 4 weeks prior to enrollment * Lansky or Karnofsky performance score of at least 50 * Life expectancy of at least 8 weeks * Recovered from acute toxic effects of all prior chemotherapy, immunotherapy, and radiotherapy * At least 7 days post last chemotherapy administration (excluding intrathecal maintenance chemotherapy) * At least 7 das post last systemic corticosteroids administration (unless physiologic replacement dosing) * No prior genetically modified cell therapy that is still detectable or virotherapy * Adequate organ function * Adequate laboratory values * Willing to participate in long-term follow-up for up to 15 years, if enrolled in the study and receive T cell infusion * Patients of childbearing/fathering potential must agree to use highly effective contraception from the time of initial T cell infusion through 12 months following the last T cell infusion Exclusion Criteria: * Presence of active clinically significant CNS dysfunction * Pregnant or breast-feeding * Unable to tolerate apheresis procedure * Presence of active malignancy other than CD19+CD22+ leukemia * Presence of active severe infection * Presence of any concurrent medical condition that, in the opinion of the Principal Investigator, would prevent the patient from undergoing protocol-specified therapy