IBC members agreed that the risk posed by the presence of 
replication competent retrovirus had been significantly diminished 
through the use of three assays: S+/L-, PCR, and 3T3 
amplification. Moreover, primate data indicated that inadvertent 
contamination posed little risk, if any, to patients. Secondly, 
the animal experiments demonstrated the ability to recover marked 
TIL cells and participants concluded that additional tests in the 
mouse system had little relevance to human trials due to 
differences in mouse and human CD4+ and CD8+ lymphocytes. 
The IBC members voted to approve the protocol with the following 
stipulations : 
1. Because the animal model had not been fully developed, 
the initial patient population should be limited to 10; 
2. As in the RAC motion to approve, only those patients who 
are determined to have a terminal illness should be 
selected for this trial; 
3. All patients must be fully informed as to the risks of 
the TIL marking procedure; and 
4 . The investigators should not proceed beyond these 
restrictions without first presenting expanded animal 
studies. 
Dr. Parkman inquired whether the IBC would require "an analogous 
animal model," or "the most analogous animal model," to which 
Dr. Singer answered that this must be assessed case-by-case. 
Dr. Walters referred HGTS members to Attachment 3 (November 10) 
and Attachment 6 (November 22), written comments submitted by 
Drs. Temin, Mclvor, Varmus, Mulligan, and Neiman (attached). He 
also noted that an Investigational New Drug (IND) application had 
been submitted to FDA for review at a December 19 meeting. 
Dr. Mclvor expressed reservations regarding the S+/L- and PCR 
assays for helper virus and the absence of a satisfactory animal 
model. He concluded that the new data answered many of his earlier 
concerns. Asked for clarification by Mr. Capron, Dr. Singer 
responded that the NIH IBC had been more concerned about the 
technical ability to recover marked TIL cells from the patients 
than the possibility of inadvertent exposure to retrovirus. 
Dr. Erickson noted that his technical concerns had been addressed 
but that he remained uncertain regarding information that would be 
gained by doing these studies in patients who would live for only 
90 days. 
Dr. Neiman expressed few residual concerns but stated that there 
must be a standard requirement for "dry run" data in all future 
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