aliquot would be grown in media contaning G418, a 
neomycin analog in which only those cells expressing 
the Neo” gene can survive. The cells would be tested 
to insure that they are virus-free, have similar 
surface antigen patterns to the parent TIL population, 
and have not changed significantly in other properties 
(including continued dependence on exogenous IL-2 for 
growth) . The treated aliquot would then be 
administered to the patient along with the bulk TIL 
population that would have been grown separately. The 
proportion of marked TIL in the final TIL population 
that would be returned to the patient would be between 
5-30%. After administration, samples of blood, lymph 
nodes, and tumor biopsy material (already being 
obtained as part of the standard TIL protocol) would be 
tested for the presence of the Neo B gene by PCR DNA 
analysis. The marked TIL would be recovered by growth 
of the tissue sample in IL-2 medium plus G418. The 
recovered cells would be studied for phenotypic and 
cytotoxic properties in order to attempt to learn why 
TIL immunotherapy is successful in some cases but not 
in others." 
Dr. Walters then related the major events of the approximate four 
months since the proposal was first submitted to the Human Gene 
Therapy Subcommittee as follows: 
June 10, 1988 Initial submission of what was technically an 
amendment of an approved clinical research project 
entitled "The Treatment of Patients with Advanced 
Cancer Using Cyclophosphamide, Interleukin-2 and 
Tumor Infiltrating Lymphocytes," to two NIH 
Clinical Research Subpanels (NCI and NHLBI). 
June 15, 1988 Proposed amendment submitted to NIH Institutional 
Biosafety Committee. 
June 20, 1988 Initial review of proposed amendment by NCI 
Clinical Research Subpanel which approved the 
amendment with the stipulation that the final 
version of the proposal be resubmitted to the 
Subpanel for final consideration, and offered ten 
recommendations for further amendment of the 
proposal . 
June 21, 1988 NHLBI Clinical Research Subpanel reviewed the 
amendment and approved it with three stipulations 
including: (1) that the Subpanel deferred to the 
RAC on procedures to ensure no infectious viral 
particles remained in the preparation; (2) that 
final approval was contingent upon investigators' 
[ 234 ] 
Recombinant DNA Research, Volume 13 
