Trial Information

Phase II Study of Metastatic Melanoma Using Lymphodepleting Conditioning Followed by Infusion of Anti-gp100:154-162 TCR-Gene Engineered Lymphocytes and ALVAC Virus Immunization

Background:

- We have engineered human peripheral blood lymphocytes (PBLs) to express a T-cell
receptor that recognizes an human leukocyte antigens (HLAA) 0201 restricted epitope
derived from the gp100 protein.

- We constructed a single retroviral vector that contains both alpha and infinity chains
and can mediate genetic transfer of this T cell receptor (TCR) with high efficiency
(greater than 30 percent) without the need to perform any selection.

- In co-cultures with HLA-A 0201 positive melanoma gp100:154-162 TCR transduced T cells
secreted significant amount of interferon (IFN)-(but no significant secretion was
observed in control co-cultures with cell lines.

gp100:154-162 TCR transduced PBL could efficiently kill -HLA-A 0201 positive tumors. There
was little or no recognition of normal fibroblasts cells.

- This TCR is over 10 times more reactive with melanoma cells than the melanoma antigen
recognized by T-cells (MART)-1 TCR that mediated tumor regression in two patients with
metastatic melanoma.

- In this trial we would like to test our hypothesis that the addition of an anti-tumor
ALVAC vaccine will result in clinical tumor regression, and persistence of the
transferred cells (as is the case in murine models).

Objectives:

Primary objectives:

-Determine if the administration of anti-gp100:154-162 TCR-engineered peripheral blood
lymphocytes, ALVAC anti-tumor immunization, and aldesleukin to patients following a
nonmyeloablative but lymphoid depleting preparative regimen will result in clinical tumor
regression in patients with metastatic melanoma.

Secondary objectives:

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

- Determine the toxicity profile of this treatment regimen.

- Determine whether treated patients develop anti-mouse TCR antibody.

Eligibility:

Patients who are HLA-A 0201 positive and 18 years of age or older must have:

- metastatic melanoma;

- previously received and have been a non-responder to or recurred after aldesleukin;

- normal values for basic laboratory values.

Patients may not have:

- concurrent major medical illnesses;

- any form of primary or secondary immunodeficiency;

- severe hypersensitivity to any of the agents used in this study;

- 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
supernatant containing the anti-gp100:154-162 TCR retroviral vector. These transduced
cells will be expanded and tested for their anti-tumor activity.

- Once engineered PBMC are demonstrated to be biologically active according to the strict
criteria outlined in the Certificate of Analysis, patients will receive a
nonmyeloablative but lymphocyte depleting preparative regimen consisting of
cyclophosphamide and fludarabine followed by intravenous infusion of ex vivo tumor
reactive, TCR gene-transduced PBMC plus intravenous (IV) aldesleukin (720,000 IU/kg q8h
for a maximum of 15 doses). Approximately 2 hours prior to cell infusion, patients will
be immunized with ALVAC virus expressing the tumor antigen. ALVAC immunization will be
repeated at 2 weeks.

- 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 and then monthly for approximately 3 to 4 months or
until off study criteria are met.

- The study will be conducted using a phase II optimal design where initially 21
evaluable patients will be enrolled. 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.

- The objective will be to determine if the combination of high dose aldesleukin,
lymphocyte depleting chemotherapy, ALVAC immunization and anti-gp100:154-162 TCR-gene
engineered lymphocytes is able to be associated with a clinical response rate that can
rule out 5 percent (p0=0.05) in favor of a modest 20 percent partial response (PR) plus
complete response (CR) rate (p1=0.20).