July 30, 1990, Human Gene Therapy Subcommittee 
Dr. Rosenberg then presented data on monkeys that had received human TILs 
transduced by the exact vectors to be used in humans, following a 20 mg/kg dose of 
cyclophosphamide. Two monkeys received no cells, two received 5 X 10^ cells per kg of 
neo-vector TIL, two received TIL^Np selected cells producing 1,942 picograms per 10^ 
cells per 24 hours, and two monkeys received non-selected TILp^p ^ concentration 
equal to the that proposed for infusion into humans based on body weight. The monkeys 
(two groups) have been followed up from 7 to 30 days, and no adverse effects and no 
toxicity have been seen in any of the monkeys. 
Dr. Rosenberg added that the supernatant will be tested for virus using the S^/L* assay 
and some more sensitive assays; Western blots will be performed on patient sera. With 
respect to long-term effects of IL-2, cells stop circulating and toxicity ceases when IL-2 is 
stopped, although in two patients there was survival of a tiny number of cells out to two 
months post cessation of IL-2. 
Dr. Rosenberg addressed the issue of transduced cells being able to produce only 20-fold 
more than normally produced, but said that with selection they hope to be able to reach 
100-fold. He added that they now had viral preparations available at titers of 5 X 10^ 
c.f.u./ml.; viral titer and availability of supernatant will not be a problem. Southern blots 
based on quantitative PCRs and survival in G418 show that transduction efficiencies are 
10-20 percent, which is very similar to the LNL6 vector used in the N2/TIL protocol. 
Dr. Rosenberg said the study was a Phase I trial, which by nature is a trial to seek the 
maximum tolerated dose of the TIL^Np, and that, if this trial is successful, a Phase II trial 
to evaluate the anticancer effects would be the normal way to proceed. This of course 
would have to be resubmitted for local approval, as well as approval by the HGTS and 
the RAC. However, each patient selected will have widely metastatic cancer and a life 
expectancy of only months. If substantial antitumor effects are seen they will be noted 
and carefully measured, as each patient will be his own control and will be receiving 
increasing numbers of cells. 
Regarding lysis. Dr. Rosenberg said that when target cells are treated with TNF or TNF 
and gamma interferon, the lysis is increased because TNF up-regulates major 
histocompatibility complex (MHC) antigens on the tumor cell surface when using 
exogenous TNF. However each TIL preparation has been checked for lysis and has 
been close to the same in 4-hour chromium release assays. 
As far as dose-response data are concerned. Dr. Rosenberg said that the investigators 
intend to begin with a one-third dose of IL-2 and that with dose escalation leeway is 
provided in terms of the number of doses that can be administered and when it is 
possible to withdraw IL-2. He noted that, even if 1/100 the dose of IL-2 were given for 
a long enough period, it could result in toxicity. Finally, if toxicity were to occur, there 
are three ways to deal with it: 
Recombinant DNA Research, Volume 14 
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