Phase I/II Study of Metastatic Melanoma Using Lymphodepleting Conditioning Followed by Infusion of Tumor Infiltrating Lymphocytes Genetically Engineered to Express IL-12

Trial Information

Phase I/II Study of Metastatic Melanoma Using Lymphodepleting Conditioning Followed by Infusion of Tumor Infiltrating Lymphocytes Genetically Engineered to Express IL-12

Background:

- Interleukin-12 (IL-12) is an important immunostimulatory cytokine. We have constructed
a retroviral vector that contains an inducible single chain IL-12 driven by an NFAT
responsive promoter which can be used to mediate transfer of this gene into anti-tumor
lymphocytes. This construct enables the secretion of IL-12 following stimulation of the
T cell receptor.

- Transduction of the IL-12 gene into mouse anti-tumor lymphocytes results in a profound
increase in the ability of these lymphocytes to mediate tumor regression following
administration to tumor bearing mice. These cells have a profound advantage in inducing
anti-tumor responses because very few cells are needed and there is no requirement for
the concomitant administration of interleukin-2 (IL-2) as is the case for conventional
cell transfer immunotherapies.

- Based on these murine studies we have now constructed a similar retrovirus that
contains an inducible human single chain IL-12 driven by an NFAT responsive promoter.
This retrovirus can be used to transduce tumor infiltrating lymphocytes (TIL) suitable
for the therapy of patients with metastatic melanoma.

Objectives:

Primary objectives:

- To evaluate the safety of the administration of IL-12 engineered TIL in patients
receiving a non-myeloablative conditioning regimen.

- Determine if the administration of IL-12 engineered TIL to patients following a
non-myeloablative but lymphoid depleting preparative regimen will result in clinical
tumor regression in patients with metastatic cancer.

Secondary objective:

-Determine the in vivo survival of IL-12 gene-engineered cells.

Eligibility:

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

- metastatic melanoma;

- ECOG performance status 0 or 1;

Design:

- TIL will be resected from metastatic deposits and grown in IL-2 using standard
techniques.

- Prior to approval of amendment A, after about 2 weeks TIL will undergo CD8 enrichment
on a Miltenyi column and then undergo a rapid expansion by exposure to OKT-3 an IL-2 in
the presence irradiated feeder cells. Four to five days later, transduction is
initiated by addition of retroviral vector supernatant containing the IL-12 gene.

With approval of amendment A, TIL will not undergo CD8 enrichment. Starting with cohort 5,
after initial growth, TIL undergo a rapid expansion by exposure to OKT-3 and IL-2 in the
presence irradiated feeder cells. Four to five days later, transduction is initiated by
addition of retroviral vector supernatant containing the IL-12 gene.

- Patients will receive a nonmyeloablative but lymphocyte depleting preparative regimen
consisting of cyclophosphamide and fludarabine followed by intravenous infusion of
IL-12 gene-transduced TIL. Cohorts of 3 patients each will receive increasing cell
doses.

- 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.

- Prior to approval of amendment A, the protocol enrolled 1 patient in each of the first
3 dose cohorts. Cohort 4 proceeded in a phase 1 dose escalation design, with of n=3.
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.

- With approval of amendment A, no additional patients will be enrolled in cohort 4, and
the protocol will enroll 1 patient in cohort 5 with a dose of 1 X 10(7) bulk young TIL
cells. Cohorts 6-12 will proceeded in a phase 1 dose escalation design, with an n=3.
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
pahse II portion. If a dose limiting toxicity occurs in the cohort 4, that cohort will
be expanded to 6 patients. If 2 DLTs are encountered in this cohort, the study will be
terminated.

- Once the MTD has been determined, the study then would proceed to the phase II portion
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 lymphocyte depleting
chemotherapy, and IL-12 gene engineered lymphocytes is associated with a clinical
response rate that can rule out 5% (p0=0.05) in favor of a modest 20% PR + CR rate
(p1=0.20).