Recombinant DNA Advisory Committee - 5/30-31/91 
He underlined that the patient will first sign the informed consent for the therapy protocol 
and only after he has signed onto this protocol will he be approached to sign on for the 
marking protocol. He said that he would remove all reference to therapy, but that he felt 
this only helped to clarify this document. He agreed that the terms "autologous" and "drug 
regimen" would be defined and added that he felt this was a constructive suggestion. 
Dr. Deisseroth said the reason he had mentioned that this had a "small chance of benefitting 
a particular individual in the future" was that if a patient participates in the marking and the 
therapeutic program and has a fairly substantial remission in terms of time and then relapses 
it could be conceivable that information would be available from the study which drive the 
investigators to subject that patient’s marrow to a more stringent purification procedure. 
In response to Dr. Mclvor's questions, Dr. Deisseroth said that he was correct in stating that 
there was no way to discriminate between normal and leukemic colonies, in contrast to Dr. 
Brenner's protocol. But he added that there are molecular assays which are totally specific 
and done on a colony-by-colony basis that could be employed. He reminded Dr. Mclvor that 
they continue to be headed in the direction of developing a fluorescent in situ analysis, as he 
had alluded to earlier. As far as the scale-up is concerned he said that GTI would be 
performing this in Houston and would be supplying the investigators with the FDA-approved 
viral supernatant. 
Dr. Mclvor asked what had been done in Dr. Deisseroth's laboratory in terms of scale-up. 
Dr. Anderson interjected that one would not want to perform a major scale-up for reason of 
cost, just to say that they can perform it. Dr. Deisseroth said that he did have some marrow 
frozen away from patients who had expired and said it would be possible to thaw this and 
expose it, but noted that this would be different than using fresh marrow from a patient and 
performing the marking. 
Dr. Mclvor said this would shed light on the issue of anticipated efficacy and said that he 
would feel more comfortable if such a scale-up could be performed. He said the committee 
had to make a decision as to whether they anticipate the protocol is actually going to provide 
some results, and one of the components in that assessment is the frequency of gene transfer. 
He said this was absolutely necessary since it is the total basis for the information that is 
anticipated to be generated. He said the committee may want to discuss whether they would 
want to approve the protocol contingent on these experiments being done, or possibly to defer 
the protocol pending the receipt of those data. 
Dr. Moen said he was not sure how to do such experiments without using the patient's fresh 
marrow. Dr. Deisseroth reiterated that they could use cryopreserved cells and grow colonies 
out of them. He said it was not a technical problem to do this, and said that it could be done 
if the committee felt it were important. 
It was pointed out that when Dr. Brenner's protocol had come before the committee there 
had been no such requirement for full scale-up, and Dr. Mclvor said he would be comfortable 
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Recombinant DNA Research, Volume 14 
