III. PROGRESS REPORT 
A. Experience vlth TIL Thera-pv 
1. Clinical results 
As of June 1, 1988, 25 patients with metastatic melanoma have been 
treated with tumor infiltrating lymphocytes in conjunction with cyclophosphamide 
and IL-2. Over one -half of evaluable patients treated at maximum doses of IL-2 
in conjunction with TIL have shown objective regression of metastatic cancer. 
Responses have also been seen in patients with brain metastases treated with 
reduced amounts of IL-2 and in patients who previously failed therapy with IL-2. 
The numbers of patients treated are small and additional patients are being added 
to this clinical treatment protocol. These patients have received up to 7.5 x 
10-^ TIL. Currently, efforts are being made to establish the dose-response 
relationship between the number of cells given, the amount of IL-2 administered, 
and the clinical response. 
Extensive studies are underway to determine predictors of clinical 
response in an effort to gain information essential for improving this treatment 
regimen. In addition to the clinical parameters that are being monitored, a 
variety of studies are being performed on the infused TIL. These studies include 
measurements of the lytic potential of' TIL, the proliferative potential of TIL in- 
the presence of autologous tumor, the phenotype of the TIL, and an analysis of 
the messenger RNA coding for lymphokines produced by these TIL. 
2 . Indium ^^ ^ labeling 
We have attempted to monitor the In vivo distribution of TIL in 
six patients by labeling approximately ten percent of the infused cells with 
Indium^^^. In all six patients the transferred TIL localized to tumor deposits 
as assessed by nuclear medicine scans as well as by biopsy of cutaneous lesions. 
These traffic studies however are limited by several factors including the short 
half life of Indium^^^ (2.8 days), the tendency of TIL to spontaneously release 
Indium^^^, and the damage caused by autoirradiation of the labeled TIL. These 
problems have prevented detailed studies of the traffic of TIL and no information 
is available concerning the prolonged survival and distribution of TIL in these 
patients. The long term distribution and the maintenance of function and 
phenotype of the infused TIL represent important issues to be addressed and have 
important implications for the future development of TIL therapy. It would be of 
great value to be able to identify the infused TIL in treated patients. The 
approach suggested in this Addition to our original protocol ought to enable us 
to study the distribution and function of TIL in patients on a long term basis. 
B . Studies on Retroviral -Mediated Gene Transfer into TIL . 
1 . Retroviral vector N2 - a selectable cell marker - 
The N2 vector (Figure 1) was constructed by modifying the Moloney murine 
leukemia virus (MoMLV) . The viral genes have been removed and a bacterial gene 
NeoR has been inserted in their place (7,8). NeoR produces an Intracellular 
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Recombinant DNA Research, Volume 14 
