Pre-IDE Submission: Clinical Protocol 
Neuroblastoma Bone Marrow Purging System 
BAXTER HEALTHCARE CORPORATION, HYLAND DIVISION 
The availability of transduction procedures that are able to mark neuroblastoma cells in 
the harvested bone marrow will facilitate addressing these issues. 
Retroviral vectors have been successfully used to mark malignant cells and cell lines in 
man. In rodent models, marked malignant cells have re-established the disease. If 
residual cells in the harvested bone marrow could be marked, it would be possible to 
determine whether the malignant cells detected at relapse were derived from the infused 
graft, and whether an ex vivo purging procedure would either minimize or e liminate such 
a possibility. 
This approach appears to be feasible for neuroblastoma since in vitro studies on human 
neuroblastoma cell lines have shown that these tumor cells can be transduced with an 
efficiency of 5-30%, and that fresh clonogenic tumor cells can.be transduced with an 
efficiency of approximately l%-3% (Santana et al, 1991). 
6. 1 .5.3 Description of Transduction Vectors 
The vectors to be used in the transduction studies are the helper-free LNL-6 retrovirus 
and its derivative GINa, which differs from LNL-6 by virtue of a deleted retroviral 
promoter sequence. This change allows different PCR primers to be used to produce a 
different sized fragment on PCR analysis. Both vectors have been extensively studied 
in rodent models and in non-human primates; no testing has been assocated with any 
adverse effect. They are currently in use in clinical trials (IND #3042) which, to date, 
have not shown side effects. The safety considerations for the transduction vectors are 
located in Appendix D. 
6. 1.5.4 Marrow Harvesting and Manipulation 
Marrow Harvesting. Transportation and Nucleated Cell Enrichment 
Marrow may be harvested at any of the participating institutions and shipped to St. Jude 
Recombinant DNA Research, Volume 16 
[463] 
