Laboratory-Treated (Central Memory/Naive) CD8+ T Cells in Treating Patients With Newly Diagnosed or Relapsed Acute Myeloid Leukemia

PRIMARY OBJECTIVES:

I. Determine the safety/potential toxicities associated with treating high-risk acute myeloid
leukemia (AML) patients with autologous CD8+ T cells (polyclonal Tn and Tcm cells;
Epstein-Barr virus-specific T cells [Tebv cells]) that have been genetically-modified to
express a high affinity WT1-specific TCR (TCRC4).

II. Determine the feasibility of reproducibly treating high-risk AML patients with autologous
CD8+ T cells (polyclonal TN and TCM cells; Tebv cells) that have been genetically-modified to
express a high affinity WT1-specific TCR (TCRC4).

III. Determine and compare the in vivo persistence in blood and at the primary tumor site
(e.g. bone marrow, chloroma) of transferred autologous CD8+ T cells (polyclonal TN and TCM
cells; TEBV cells) that have been genetically-modified to express a high affinity
WT1-specific TCR (TCRC4).

EXPLORATORY OBJECTIVES:

I. Determine whether adoptively transferred autologous TCRC4-transduced CD8+ cells have
anti-tumor activity in patients with acute myeloid leukemia.

II. In patients with measurable minimal residual disease (MRD) at the time of infusion of
TCRC4-transduced CD8+ cells, changes in leukemic tumor burden will be measured by morphology,
flow cytometry, cytogenetics/fluorescence in situ hybridization (FISH) and/or molecular
testing at baseline and after infusion of T cells.

III. In all patients (those with or without measurable tumor burden prior to T cell transfer,
including patients who convert to MRD-negative status during consolidation), the probability
of relapse, disease-free survival and overall survival of patients receiving TCRC4-transduced
CD8+ cells will be compared with patients in the observation arm.

IV. Determine and compare the migration to the primary tumor site of subsets of the
adoptively transferred autologous TCRC4-transduced CD8+ T cells (polyclonal TN and TCM cells;
TEBV cells).

V. Determine and compare the in vivo functional capacity of transferred polyclonal autologous
TCRC4-transduced CD8+ TCM, TN and TEBV CD8+ cells.

OUTLINE:

Beginning 4 weeks after completion of last course of consolidation chemotherapy, patients
receive autologous WT1-TCRc4 gene-transduced CD8+ TCM/TN lymphocytes intravenously (IV) over
1-4 hours on days 0 and 14. Beginning 6 hours after the second infusion of T cells, patients
also receive aldesleukin subcutaneously (SC) twice daily (BID) for 14 days in the absence of
disease progression or unacceptable toxicity. Patients who have clinically benefitted from T
cell therapy may receive additional infusions of T cells and aldesleukin at the discretion of
the principal investigator (PI) and the attending physician.

After completion of study treatment, patients are followed up weekly for 4 weeks, at 2, 3, 6,
and 12 months, and then annually for 14 years thereafter.

Inclusion Criteria:

- Patients with (non-M3) acute myeloid leukemia (AML)

- Patients must be >= 15 kg

- Patients or parents/legal guardian must be able to give informed consent

- Patients must be able to provide blood and marrow samples and to undergo the
procedures required for this protocol

- Elevated expression of WT1 in pre-treatment bone marrow or peripheral blood by either
of two methods:

- Increased expression of WT1 determined if the number of copies of WT1 divided by
the number of copies of ABL x 10^4 is > 250 for bone marrow, or > 50 for
peripheral blood;

- Demonstration of WT1 overexpression will be determined by immunohistochemical
staining (IHC) in blasts as compared to adjacent normal myeloid and erythroid
precursors, as determined by a Fred Hutchinson/Seattle Cancer Care Alliance
pathologist

- Demonstration of disease response to induction chemotherapy, in that patients must
have achieve a morphologic remission (marrow that is at least 10% cellular with < 5%
blasts on morphologic review) after 1-2 induction cycles, regardless of minimal
residual disease or incomplete hematologic recovery (CRi)/incomplete platelet recovery
(CRp) status

- Determination of "high-risk" disease; subjects must meet one of the determinants of
"high-risk disease", in terms of being at very high risk for relapse without
allogeneic stem cell transplant, as per one of the follow criteria:

- A designation of "adverse" risk disease at the time of diagnosis, as defined by
cytogenetic and molecular abnormalities specifically outlined in the 2017
European LeukemiaNet (ELN) guidelines for diagnosis and management of AML; these
patients will meet "high-risk" designation, regardless of minimal residual
disease or CRi/CRp status

- Relapsed leukemia; patients with cytogenetic or molecular classification other
that adverse risk by ELN who go on to demonstrate disease relapse after a minimum
duration of remission of 6 months, but who then attain a second complete
remission with repeat induction chemotherapy; these patients will meet
"high-risk" designation, regardless of minimal residual disease or CRi/CRp status

- Minimal residual disease, as defined by having detectable disease by one of the
following criteria , but otherwise being in morphologic remission

- MRD by flow cytometry at any time after induction chemotherapy or during
consolidation chemotherapy, when patients are otherwise classified as being
in morphologic remission, and as defined by any abnormal myeloid blasts
identified by flow cytometric analysis

- Cytogenetic MRD, as defined by a disease-specific abnormal karyotype at any
point in patients who are otherwise in morphologic remission

- Molecular minimal residual disease (MRD) with one of the following markers,
as specified below, in patients who are otherwise in morphologic remission:

- A normalized copy number (NCN) of > 0.001 for CBFB/MYHI1 or a
normalized copy number (NCN) of > 0.050 for AMLI/ETO (RUNXI/RUNX1T1)
after at least 4 cycles of consolidation chemotherapy

- A < 2 log reduction in either CBFB/MYH11 or AMLI/ETO (RUNX1/RUNX1T1) in
the bone marrow at the time of post-induction disease restaging
(immediately after 1-2 cycles of induction therapy)

- CRi/CRp, as defined by neutrophil count < 1000/ul (CRi) and/or platelet
count < 100,000/ul (CRp), but otherwise being in morphologic remission; in
pediatric patients, a platelet threshold of < 80,000/ ul will be used, as
per consensus pediatric response criteria

- Human leukocyte antigen (HLA)-A*02:01 expression must be present for patient to be on
treatment arm, HLA-A*02:01 expression absent in patients designated to observation arm

ELIGIBILITY FOR APHERESIS/BLOOD COLLECTION:

• HLA-A*02:01 expression

ELIGIBILITY FOR TREATMENT WITH TCRC4-TRANSDUCED CD8+ CELLS

- Response to therapy and completion of at least one cycle of consolidation therapy, and
with disease status meeting one of the aforementioned "high-risk" criteria at the time
of post-induction disease restaging as already outlined above

- Hematologic recovery from induction and other post-remission therapy (absolute
neutrophil count [ANC] > 200/ul, platelet count > 20,000/ul) at the time of the study
intervention

- No plan for allogeneic stem cell transplantation within 3 months

- Elevated expression above baseline of WT1 in bone marrow or peripheral blood

- Additionally, patients treated in stage 1, cohort #3 must be EBV seropositive, given
the inclusion of T cells derived from an EBV-specific subset in this group

- Continued morphologic remission (< 5% blasts in the marrow, no circulating blasts or
known extramedullary relapse) within 4 weeks of receiving the study intervention
(specified as T cell infusion for cohort 1, or the start of lymphodepleting
chemotherapy for cohorts 2 and 3)

- ELIGIBILITY FOR OBSERVATION ARM

- The patient meets all of the eligibility criteria for enrollment, but lacks expression
of HLA-A*0201 as is needed to be enrolled on the treatment arm and for apheresis

Exclusion Criteria:

- Active autoimmune disease (e.g. systemic lupus erythematosus, vasculitis, infiltrating
lung disease, inflammatory bowel disease) in which possible progression during
treatment would be considered unacceptable by the investigators

- Previous allogeneic hematopoietic cell transplant (HCT)

- Any condition or organ toxicity deemed by the principal investigator (PI) or the
attending physician to place the patient at unacceptable risk for treatment on the
protocol

- Pregnant women, nursing mothers, men or women of reproductive ability who are
unwilling or unable to use effective contraception or abstinence; women of
childbearing potential must have a negative pregnancy test within two weeks prior to
enrollment and initiation of treatment

- Clinically significant and ongoing immune suppression including, but not limited to:
systemic immunosuppressive agents such as cyclosporine or corticosteroids (at an
equivalent dose of 0.5 mg prednisone/kg per day, or higher), chronic lymphocytic
leukemia (CLL), uncontrolled human immunodeficiency virus (HIV) infection (untreated
or detectable viral load within 3 months of enrollment)

- Acute promyelocytic leukemia (M3 leukemia, per French-American-British classification)

EXCLUSION FOR TREATMENT WITH TCRC4-TRANSDUCED CD8+ CELLS

- Unable to generate antigen-specific WT1-specific CD8+ T cells for infusions; however,
if a lower than planned number of cells is available, the patient will have the option
to receive the generated WT1-specific T cells

- Systemic steroids should be stopped 2 weeks before the start of treatment; topical and
inhaled steroids are allowed

- Symptomatic and refractory central nervous system (CNS) leukemia

- Absolute neutrophil count (ANC) < 200/ul prior to treatment

- Platelets < 20,000/ul prior to treatment

- If a patient meets other treatment eligibility but otherwise demonstrates delayed or
poor recovery of peripheral blood counts to the above neutrophil and/or platelet
thresholds, then treatment with the T cell intervention will be allowed if:

- Neutrophil and/or platelet counts remain below the thresholds after a period of
at least 6 weeks from last systemic chemotherapy; OR neutrophil and/or platelet
counts remain below the thresholds in the setting of a maintenance therapy, such
as midostaurin; and

- The patient has detectable leukemia (e.g. flow cytometry positive or MRD by FISH
or molecular testing); and

- The P.l. or treating physician documents that the likely cause of cytopenias is
underlying disease as opposed to another cause (e.g. medication)

- Ongoing >= grade 3 cardiac, pulmonary, renal, gastrointestinal or hepatic toxicities
according to National Cancer Institute (NCI) Common Terminology Criteria for Adverse
Events (CTCAE) version 4 toxicity criteria

- Karnofsky performance status score (age >= 16 years) or Lansky play score (age < 16
years) =< 40%

- Medical or psychological conditions that, according to the PI, would make the patient
unsuitable candidate for cell therapy

- Pregnancy or breast-feeding; women of childbearing potential must have a negative
serum or urine beta-human chorionic gonadotropin (hCG) pregnancy test result within 14
days before the first dose of WT1-specific T cell infusion; woman of non-childbearing
potential will be defined as being postmenopausal greater than one year or who have
had a bilateral tubal ligation or hysterectomy; all recipients of WT1-specific T cells
will be counseled to use effective birth control during participation in this study
and for 12 months after the last T cell infusion

- Treatment with alemtuzumab or other T cell-depleting antibodies within 6 months of T
cell therapy

- Documented new infection within 24 hours of T cell infusion, or concern for new
infection as suggested by an oral temperature > 38.2 degrees Celsius (C) within 24
hours of T cell infusion

- ln patients who have T cells delayed because of development of fever (oral
temperature > 38.2 degrees C) and who subsequently become afebrile (38.2 degrees
C or less) for 24 hours without a documented infection, T cells may be
administered

- ln patients with a documented new infection within 24 hours of planned T cell
infusion, they may go on to receive T cells after administration of directed
antibiotic therapy and if they subsequently remain afebrile (38.2 degrees C or
less) for at least 24 hours, and if it is deemed clinically appropriate by the Pl

- Pre-existing infections requiring chronic maintenance therapy (e.g. chronic
hepatitis B virus [HBV] or treated bacterial infections) are not an exclusion for
T cell infusion as long as patients are on appropriate antimicrobial therapy for
at least 1 month (e.g. for chronic hepatitis B or C viral infection) and who
remain afebrile and without symptomatic evidence for uncontrolled chronic
infection within 24 hours of T cell infusion; patients should also have a
negative HIV test by viral load within 3 months of treatment