Human Gene Therapy Subcommittee - 7/30/90 
Dr. Leventhal said the protocol will involve patients with 
glioma, AML and neuroblastoma without detectable tumor in the 
marrow who are eligible for autologous bone marrow transplant 
(ABMT) protocols within St. Jude's Hospital. She said the 
protocol calls for increasing the number of harvested bone marrow 
cells by 30 percent. Thirty percent of the cells will be taken, 
following cell separation, to be treated and transduced with 
marker genes while the remainder will be frozen. Following 
reinfusion of marrow into the patients, the bone marrow and 
peripheral blood will be checked for appearance of the vector and 
analyzed in line with the objectives of the study. 
Dr. Leventhal presented the following as questions concerning 
safety of the protocol: 
1. Is there a reason to think that incubation of bone 
marrow with viral vector will decrease the likelihood 
of a graft take, and what are the data relevant to this 
point? 
2. Have marrow cells been grown, in vitro, after 
treatment? 
3. Will the one-third treated and untreated marrows be 
combined for reinfusion? If so, is there a potential 
for suppression of marrow growth as a whole? 
4. Will there be a back-up marrow source? 
She said the plans for the possible use of growth factors are 
sketchy. Further, specific growth factors may stimulate the 
growth of tumors as well as normal marrow cells. She said any 
such studies should be spelled out in great detail and considered 
individually by tumor type and growth factor combinations. 
Dr. Leventhal said she had the following questions about the 
design of the study; 
1. How will it be possible to determine what cells are 
labeled in vitro when there is no detectable tumor at 
the time of harvest? 
2. Have mixing studies been done? 
3. Is there a reason to think that transfection of tumor 
cells will be selective vis-a-vis normal marrow stem 
cells? 
Recombinant DNA Research, Volume 14 
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