CAR T Cell Receptor Immunotherapy Targeting VEGFR2 for Patients With Metastatic Cancer

Background:

• We have constructed a single retroviral vector that contains a chimeric T cell receptor (CAR) that recognizes the Vascular Endothelial Growth Factor Receptor 2 (VEGFR2), which can be used to mediate genetic transfer of this CAR with high efficiency (> 50%) without the need to perform any selection. Administration of VEGFR2 CAR transduced cells inhibited tumor growth in several different models in different mouse strains.
• In co-cultures with VEGFR2 expressing cells, anti-VEGFR2 transduced T cells secreted significant amounts of interferon (IFN) gamma with high specificity.

Objectives:

Primary objectives:

• To evaluate the safety of the administration of anti-VEGFR2 CAR engineered cluster of differentiation 8 (CD8)+ peripheral blood lymphocytes in patients receiving a non- myeloablative conditioning regimen, and aldesleukin.
• Determine if the administration of anti-VEGFR2 CAR engineered CD8+ 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.

Secondary objective:

-Determine the in vivo survival of CAR gene-engineered cells.

Eligibility:

Patients who are 18 years of age or older must have:

• metastatic cancer;
• previously received and have been a non-responder to or recurred after standard care for metastatic disease;

Patients may not have:

-contraindications for high dose aldesleukin administration.

Design:

• Peripheral blood mononuclear cells (PBMC) obtained by leukapheresis (approximately 5 times 10(9) cells) will be cultured in the presence of anti-CD3 (OKT3) and aldesleukin in order to stimulate T-cell growth.
• Transduction is initiated by exposure of approximately 10(8) to 5 times 10(8) cells to retroviral vector supernatant containing the VEGFR2 genes.
• 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 CD8+ PBMC plus intravenous (IV) aldesleukin. With approval of amendment C, aldesleukin (based on total body weight) will be administered at a dose of 72,000 IU/kg as an intravenous bolus over a 15 minute period approximately every eight hours (+/- 1 hour) beginning within 24 hours of the cell infusion and continuing for up to 5 days (maximum 15 doses
• Patients will undergo complete evaluation of tumor with physical examination, computed tomography (CT) of the chest, abdomen and pelvis and clinical laboratory evaluation four to six weeks after treatment. If the patient has stable disease (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. Initially, the protocol will enroll 1 patient in each dose cohort unless that patient experiences a dose limiting toxicity (DLT). Should a single patient experience a dose limiting toxicity due to the cell transfer at a particular dose level, additional patients would be treated at that dose to confirm that no greater than 1/6 patients have a DLT prior to proceeding to the next higher level. If a level with 2 or more DLTs in 3-6 patients has been identified, three additional patients will be accrued at the next-lowest dose, for a total of 6, in order to further characterize the safety of the maximum tolerated dose prior to starting the phase II portion. If a dose limiting toxicity occurs in the first cohort, that cohort will be expanded to 6 patients. If 2 DLTs are encountered in this cohort, the study will be terminated. If IFN-gamma levels increase substantially (as defined in the protocol) in the patient in a cohort compared to the prior patient, the cohort would be expanded to an n=3 to obtain more data on this phenomenon. If one of these 3 patients experience a DLT, the cohort will be expanded to six patients. Following amendment C, patients will be enrolled in cohorts 8-11, with the non-myeloablative chemotherapy regimen, cells and low dose aldesleukin following a conventional 3+3 design. Once the maximum tolerated dose (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 metastatic melanoma and renal cancer, and cohort 2 will include patients with other types of metastatic cancer.
• 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.
• The objective will be to determine if the combination of aldesleukin, lymphocyte depleting chemotherapy, and anti-VEGFR2 CAR-gene engineered CD8+ lymphocytes is able to be associated with a clinical response rate that can rule out 5% (p0=0.05) in favor of a modest 20% partial response (PR) + complete response (CR) rate (p1=0.20).