CAR T Cell Receptor Immunotherapy Targeting Mesothelin for Patients With Metastatic Cancer

Background:

- We have constructed a single retroviral vector that contains a chimeric T cell receptor
(CAR) that recognizes mesothelin, which can be used to mediate genetic transfer of this
CAR with high efficiency (> 50%) without the need to perform any selection.

- In co-cultures with mesothelin expressing cells, anti-mesothelin transduced T cells
secreted significant amounts of IFN-gamma with high specificity.

Objectives:

Primary Objectives:

- To evaluate the safety of the administration of anti-mesothelin CAR engineered
peripheral blood lymphocytes in patients receiving a non- myeloablative conditioning
regimen, and aldesleukin.

- Determine if the administration anti-mesothelin CAR engineered peripheral blood
lymphocytes and aldesleukin to patients following a nonmyeloablative but lymphoid
depleting preparative regimen will result in clinical tumor regression in patients with
metastatic cancer.

Eligibility:

Patients who are 18 years of age or older must have

- Metastatic or unresectable cancer that expresses mesothelin;

- Previously received and have been a non-responder to or recurred after standard care;

Patients may not have:

-Contraindications for low dose aldesleukin administration.

Design:

- PBMC obtained by leukapheresis will be cultured in order to stimulate T-cell growth.

- Transduction is initiated by exposure of approximately 10^8 to 5 X 10^8 cells to
retroviral vector supernatant containing the anti-mesothelin CAR.

- Patients will receive a nonmyeloablative but lymphocyte depleting preparative regimen
consisting of cyclophosphamide and fludarabine followed by intravenous infusion of ex
vivo CAR gene-transduced PBMC plus low dose IV aldesleukin

- Patients will undergo complete evaluation of tumor with physical examination, CT of the
chest, abdomen and pelvis and clinical laboratory evaluation four to six weeks after
treatment. If the patient has SD or tumor shrinkage, repeat complete evaluations will be
performed every 1-3 months. After the first year, patients continuing to respond will
continue to be followed with this evaluation every 3-4 months until off study criteria
are met.

- The study will be conducted using a Phase I/II optimal design. The protocol will proceed
in a phase 1 dose escalation design. Once the MTD has been determined, the study then
would proceed to the phase II portion. Patients will be entered into two cohorts based
on histology: cohort 1 will include patients with mesothelioma, and cohort 2 will
include patients with other types of cancer that express mesothelin.

- For each of the 2 strata evaluated, the study will be conducted using a phase II optimal
design where initially 21 evaluable patients will be enrolled. For each of these two
arms of the trial, if 0 or 1 of the 21 patients experiences a clinical response, then no
further patients will be enrolled but if 2 or more of the first 21 evaluable patients
enrolled have a clinical response, then accrual will continue until a total of 41
evaluable patients have been enrolled in that stratum.

- INCLUSION CRITERIA:

1. Metastatic or unresectable measurable cancers that express mesothelin. As in
other protocols conducted by Dr. Hassan in the NCI, epithelial mesotheliomas and
pancreatic cancers do not need to be assessed for mesothelin expression since all
of these tumors have been shown to express mesothelin. Other metastatic or
unresectable cancers must be shown to expresses mesothelin as assessed by RT-PCR
or immunohistochemistry on tumor tissue. Bi-phasic mesotheliomas must express
mesothelin on greater than 50% of the cells in the epithelial component.
Diagnosis will be confirmed by the Laboratory of Pathology, NCI.

2. Patients must have previously received at least one systemic standard care (or
effective salvage chemotherapy regimens) for metastatic or unresectable disease,
if known to be effective for that disease, and have been either non-responders
(progressive disease) or have recurred.

3. Greater than or equal to 18 years of age and less than or equal to 70 years of
age.

4. Willing to sign a durable power of attorney

5. Able to understand and sign the Informed Consent Document

6. Clinical performance status of ECOG 0 or 1.

7. Patients of both genders must be willing to practice birth control from the time
of enrollment on this study and for up to four months after treatment.

8. Serology:

1. Seronegative for HIV antibody. (The experimental treatment being evaluated
in this protocol depends on an intact immune system. Patients who are HIV
seropositive can have decreased immunecompetence and thus be less responsive
to the experimental treatment and more susceptible to its toxicities.)

2. Seronegative for hepatitis B antigen, and seronegative for hepatitis C
antibody. If hepatitis C antibody test is positive, then patient must be
tested for the presence of antigen by RT-PCR and be HCV RNA negative.

9. Women of child-bearing potential must have a negative pregnancy test because of
the potentially dangerous effects of the treatment on the fetus.

10. Hematology:

1. Absolute neutrophil count greater than 1000/mm(3) without the support of
filgrastim.

2. WBC (> 3000/mm(3)).

3. Platelet count greater than 100,000/mm(3).

4. Hemoglobin greater than 8.0 g/dl.

11. Chemistry:

1. Serum ALT/AST less or equal to 2.5 times the upper limit of normal.

2. Serum creatinine less than or equal to 1.6 mg/dl.

3. Total bilirubin less than or equal to 1.5 mg/dl, except in patients with
Gilbert s Syndrome who must have a total bilirubin less than 3.0 mg/dl.

12. More than four weeks must have elapsed since any prior systemic therapy at the
time the patient receives the preparative regimen, and patients toxicities must
have recovered to a grade 1 or less (except for toxicities such as alopecia or
vitiligo).

Note: Patients may have undergone minor surgical procedures within the past 3
weeks, as long as all toxicities have recovered to grade 1 or less.

13. Subject s must be co-enrolled in protocol 03-C-0277.

EXCLUSION CRITERIA:

1. Patients with sarcomatoid mesothelioma as mesothelin is not expressed in this type of
mesothelioma.

2. Women of child-bearing potential who are pregnant or breastfeeding because of the
potentially dangerous effects of the treatment on the fetus or infant.

3. Patients with known brain metastases.

4. Patients receiving full dose anticoagulative therapy.

5. Active systemic infections (e.g.: requiring anti-infective treatment), coagulation
disorders or any other major medical illnesses.

6. Any form of primary immunodeficiency (such as Severe Combined Immunodeficiency
Disease).

7. Concurrent opportunistic infections (The experimental treatment being evaluated in
this protocol depends on an intact immune system. Patients who have decreased immune
competence may be less responsive to the experimental treatment and more susceptible
to its toxicities).

8. Patients with diabetic retinopathy.

9. Concurrent Systemic steroid therapy.

10. History of severe immediate hypersensitivity reaction to any of the agents used in
this study.

11. History of coronary revascularization or ischemic symptoms.

12. Documented LVEF of less than or equal to 45% tested in patients with:

- Clinically significant atrial and/or ventricular arrhythmias including but not
limited to: atrial fibrillation, ventricular tachycardia, second or third degree
heart block, chest pain, or ischemic heart disease

- Age greater than or equal to 65 years old

13. Documented FEV1 less than or equal to 60% predicted tested in patients with:

- A prolonged history of cigarette smoking (20 pk/year of smoking within the past 2
years).

- Symptoms of respiratory dysfunction

14. Patients who are receiving any other investigational agents.