Human Gene Therapy Subcommittee - 7/30/90 
particular cell was a result of residual tumor in the 
transplanted cells or a residual cell in the marrow. Dr. Brenner 
said this could only be done if there were a multiplicity of 
cells which contribute, in which case some cells would be marked 
and others not. 
Dr. Parkman reiterated his concerns about multiple protocols 
being put forward under the rubric of a single proposal and said 
he felt it would be easier to review them as separate proposals. 
Dr. Brenner said that despite there being three different 
protocols, the only issue for the subcommittee was the gene 
marking portion of the experiments, which was identical for all 
three. Dr. Parkman said that was true; however, the reason for 
performing the gene manipulation in each case is different and 
must be viewed separately in terms of risks and benefits. 
Dr. Anderson said the only problem with submitting them as three 
separate protocols is that there would then be a necessity to 
submit three responses to the "Points to Consider," three sets of 
CV's, and three sets of documentation. The result would be even 
more difficult in finding information contained within the 
material. 
Drs. Mulligan, Leventhal and Parkman discussed various assay 
techniques that could be employed in trying to determine 
acceptable preclinical data in each of the three diseases under 
consideration. Dr. Mulligan summed this up as requiring assays: 
1. To demonstrate infection of the range of 
hematopoietic cells of interest, so that the 
progenitor cells giving rise to the cancers 
could be ascertained; 
2. To answer questions of the necessity of 
growth factors, the difference of infection 
between purged and unpurged cells, and the 
difference between marrow from previously 
treated patients versus patients who are non- 
ablated. 
Dr. Mulligan moved that further review of the protocol be 
deferred until a proper collection of preclinical data could be 
made. Mr. Brewer seconded the motion. 
Dr. Miller suggested a mechanism be set up whereby an 
investigator could meet with either a subcommittee of the HGTS or 
perhaps individual expert members, or be able to come in and seek 
guidance in protocol preparation at various stages before formal 
Recombinant DNA Research, Volume 14 
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