CD19/CD22 Chimeric Antigen Receptor (CAR) T Cells in Children and Young Adults With Recurrent or Refractory CD19/CD22-expressing B Cell Malignancies

Background:

- Acute lymphoblastic leukemia (ALL) accounts for approximately 25% of childhood cancer.
Survival rates have improved, but outcomes for some subgroups, including infants and
young adults remain poor, and survival for patients who relapse is < 50%, despite
allogeneic stem cell transplant following second remission.

- CD19 immune escape has been observed by several groups following CD19-CAR therapy for
B-ALL. Investigation of this phenomenon reveals a complex biology responsible for loss
or downregulation of CD19 expression observed in these cases.

- Sequential therapy using CD22-CARs to treat CD19 dim/lo escape is associated with rapid
development of resistance due to CD22 downregulation. This trial will test whether
simultaneous targeting of CD19 and CD22 using a novel bivalent CD19/22-CAR is safe and
feasible.

Objectives:

-Assess the safety of administering escalating doses of autologous CD19/CD22-CAR engineered T
cells that meet established release specifications in children and young adults with
CD19+CD22+ B cell ALL or lymphoma following a cyclophosphamide/fludarabine conditioning
regimen.

Eligibility:

-Patients between 3 years and 30 years of age, with CD19+/CD22+ B cell ALL or lymphoma who
have relapsed or have refractory disease after at least one standard chemotherapy regimen and
one salvage regimen, with no alternative curative options who meet standard Phase I
eligibility criteria.

Design:

- Phase I, 3 + 3 dose escalation design using the following dose levels: -1: 1 x 10^5
transduced T cells/kg (plus or equal to 20%); 1: 3 x 10^5 transduced T cells/kg (plus or
equal to 20%); 2: 1 x 10^6 transduced T cells/kg; and 3: 3 x 10^6 transduced T cells/kg
plus or equal to 20%)

- Patients will receive a lymphodepleting preparative regimen of fludarabine (25 mg/m2/d x
3 on Days -4, -3,-2) and cyclophosphamide (900 mg/m2/d x 1 on Day -2) followed by
infusion of CD19/CD22-CAR T-cells on D0.

- Patients will be evaluated sequentially for toxicity, antitumor effects, CAR expansion
and persistence, as well as research correlatives.

- INCLUSION CRITERIA:

- Diagnosis

- Patient must have a B cell ALL (inclusive of CML with ALL transformation) or
lymphoma and must have relapsed or refractory disease after at least one standard
chemotherapy regimen and one salvage regimen. In view of the PI and the primary
oncologist, there must be no available alternative curative therapies and
subjects must be either ineligible for allogeneic stem cell transplant (SCT),
have refused SCT, recurred after SCT, or have disease activity that prohibits SCT
at the time of enrollment. Patients who have undergone autologous SCT will be
eligible, and patients that have undergone allogeneic SCT will be eligible if, in
addition to meeting other eligibility criteria, they have no evidence of GVHD and
have been without immunosuppressive agents for at least 30 days. Patients with
Philadelphia chromosome + ALL must have failed prior tyrokine kinase inhibitor.

- Patients must have measurable or evaluable disease at the time of enrollment,
which may include any evidence of disease including minimal residual disease
detected by flow cytometry.

- CD22/CD19 Expression

- CD19 expression must be detected on greater than 15% of the malignant cells by
immunohistochemistry or greater than 90% by flow cytometry. The choice of whether
to use flow cytometry or immunohistochemistry will be determined by what is the
most easily available

tissue sample in each patient. In general, immunohistochemistry will be used for lymph node
biopsies, flow cytometry will be used for peripheral blood and bone marrow samples. CD22+ B
cell malignancy is required and CD22 expression levels will be documented when available,
but a specific level of expression is not an eligibility requirement; it may be documented
as positive or negative.

- Age:

--Greater than or equal to 3 years of age (and at least 15 kg) and less than or equal
to 30 years of age at time of enrollment (> 3 years to < 30 years). NOTE: The first
patient in each dose cohort must be greater than or equal to 18 years of age.

- Clinical Performance

--Clinical performance status: Patients > 16 years of age: Karnofsky greater than or
equal to 50%; Patients < 16 years of age: Lansky scale greater than or equal to 50%.
Subjects who are unable to walk because of paralysis, but who are upright in a
wheelchair will be considered ambulatory for the purpose of calculating the
performance score.

- Patients must have normal organ and marrow function as defined below:

- leukocytes >750/mcL*

- platelets >50,000/mcL*

- total bilirubin <2 X ULN (except in the case of subjects with documented Gilbert
s disease > 3x ULN)

- AST(SGOT)/ALT(SGPT) <10 X institutional upper limit of normal

- creatinine within for age and laboratory normal ranges

OR

- creatinine clearance >60 mL/min/1.73 m2 for patients with creatinine levels above
institutional normal.

- Age: less than or equal to 5. Maximun Serum Creatinine (mg/dL): < 0.8

- Age: 5 < age less than or equal to 10. Maximum Serum Creatinine (mg/dL):< 1.0

- Age: >10. Maximum Serum Creatinine (mg/dL): < 1.2

* if these cytopenias are not judged by the investigator to be due to underlying
disease (i.e. potentially reversible with anti-neoplastic therapy); A subject will not
be excluded because of pancytopenia greater than or equal to Grade 3 if it is due to
disease, based on the results of bone marrow studies.

-CNS Status:

- a. Subjects with leukemia with the following CNS status are eligible only in the
absence of neurologic symptoms suggestive of CNS leukemia, such as cranial nerve
palsy:

- CNS 1, defined as absence of blasts in cerebral spinal fluid (CSF) on cytospin
preparation, regardless of the number of WBCs;

- CNS 2, defined as presence of < 5/uL WBCs in CSF and cytospin positive for
blasts, or > 5/uL WBCs but negative by Steinherz/Bleyer algorithm:

- CNS 2a: < 10/uL RBCs; < 5/uL WBCs and cytospin positive for blasts;

- CNS 2b: greater than or equal to 10/uL RBCs; < 5/uL WBCs and cytospin
positive for blasts;

- CNS 2c: greater than or equal to 10/uL RBCs; greater than or equal to 5/uL
WBCs and cytospin positive for blasts but negative by Steinherz/Bleyer
algorithm.

- b. Subjects with lymphoma

- Subjects must have no signs or symptoms of CNS disease or detectable evidence of
CNS disease on MRI at the time of screening. Subjects who have been previously
treated for CNS disease but have no evidence of disease at screening are
eligible.

Patients with history of allogeneic stem cell transplantation are eligible if at least 100
days post-transplant, if there is no evidence of active GVHD and no longer taking
immunosuppressive agents for at least 30 days prior to enrollment.

- Contraception:

--Patients of child-bearing or child-fathering potential must be willing to practice
birth control from the time of enrollment on this study and for four months after
receiving the preparative regimen.

- Cardiac function: Left ventricular ejection fraction greater than or equal to 45% or
fractional shortening greater than or equal to 28%, and no clinically significant ECG
findings

- Pulmonary Function

- Baseline oxygen saturation >92% on room air at rest

- Patients with respiratory symptoms must have a DLCO/adjusted > 45%. For children who
are unable to cooperate for PFTs they must not have dyspnea at rest or known
requirement for supplemental oxygen.

- Ability of subject or Legally Authorized Representative (LAR) to understand and the
willingness to sign a written informed consent document.

For subjects <18 years old their legal guardian must give informed consent. Pediatric
subjects will be included in age appropriate discussion and verbal assent will be obtained
for those > 7 years of age, when appropriate.

EXCLUSION CRITERIA:

Subjects meeting any of the following criteria are not eligible for participation in the
study:

- Recurrent or refractory ALL limited to isolated testicular or isolated central nervous
system (CNS) disease.

- Subjects with radiologically-detected CNS lymphoma or CNS 3 disease (presence of
greater than or equal to 5/micro L WBCs in CSF and cytospin positive for blasts [in
the absence of a traumatic lumbar puncture] and/or clinical signs of CNS leukemia
and/or radiographic signs of leptomeningeal disease);

- Hyperleukocytosis (greater than or equal to 50,000 blasts/micro L) or rapidly
progressive disease that in the estimation of the investigator and sponsor would
compromise ability to complete study therapy;

- Pregnant women are excluded from this study because the study agents have the
potential for teratogenic or abortifacient effects. Because there is an unknown but
potential risk for adverse events in nursing infants secondary to treatment of the
mother with the study agents, breastfeeding should be discontinued.

- Systemic chemotherapy less than or equal to 2 weeks (6 weeks for clofarabine or
nitrosoureas) or radiation therapy less than or equal to 3 weeks prior to apheresis;

--Exceptions:

- a. There is no time restriction in regard to prior intrathecal chemotherapy
provided there is complete recovery from any acute toxic effects of such;

- b. Subjects receiving hydroxyurea may be enrolled provided there has been no
increase in dose for at least 2 weeks prior to starting apheresis;

- c. Patients who are on standard ALL maintenance type chemotherapy (vincristine,
6-mercaptopurine, oral methotrexate or tyrosine kinase inhibitors in patients
with Ph+ALL) may be enrolled provided that chemotherapy is discontinued at least
1 week prior to apheresis.

- d. Subjects receiving steroid therapy are allowed provided there has been no
increase in dose for at least 1 week prior to starting apheresis; patients on
physiologic steroids will not be excluded.

- e. For radiation therapy: Radiation therapy must have been completed at least 3
weeks prior to enrollment, with the exception that there is no time restriction
if the volume of bone marrow treated is less than 10% and also the subject has
measurable/evaluable disease outside the radiation port

- Other anti-neoplastic investigational agents currently or within 30 days prior to
apheresis (i.e. start of protocol therapy);

- Subjects must have recovered from the acute side effects of their prior therapy, such
that eligibility criteria are met. Cytopenias deemed to be disease-related and not
therapy-related are exempt from this exclusion.

- Prior CAR therapy within 30 days prior to apheresis or prior CAR therapy at any time
with evidence for persistence of CAR T cells in blood samples (circulating levels of
genetically modified cells of greater than or equal to 5% in peripheral blood by flow
cytometry).

- Prior monoclonal antibody therapy within 5 half-lives or 7 days prior to apheresis,
whichever is greater.

- HIV/HBV/HCV Infection:

- a. Seropositive for HIV antibody. (Patients with HIV are at increased risk of
lethal infections when treated with marrow-suppressive therapy. Appropriate
studies will be undertaken in patients receiving combination antiretroviral
therapy in the future should study results indicate effectiveness.)

- b. Seropositive for hepatitis C or positive for Hepatitis B surface antigen
(HbsAG).

- Uncontrolled, symptomatic, intercurrent illness including but not limited to
infection, congestive heart failure, unstable angina pectoris, cardiac arrhythmia,
psychiatric illness, or social situations that would limit compliance with study
requirements or in the opinion of the PI would pose an unacceptable risk to the
subject;

- Second malignancy other than in situ carcinoma of the cervix, unless the tumor was
treated with curative intent at least two years previously and subject is in
remission;

- History of severe, immediate hypersensitivity reaction attributed to compounds of
similar chemical or biologic composition to any agents used in study or in the
manufacturing of the cells.

- Recruitment Strategies

The following recruitment strategies will be employed to elicit potential candidates for
this trial:

1. Listed on clinical trials.gov;

2. Listed in PDQ;

3. In addition, patients treated on other institutional trials who are eligible for
participation will be offered participation in this study

Prior to distribution of any recruitment materials, such materials will be submitted to the
IRB for review.