Recombinant DMA Advisory Committee - 6/9-10/94 
investigators propose to determine whether the addition of growth factors enhances 
engraftment and persistence of the engrafted cells. Two portions of marrow will be 
marked with neo^ using two distinguishable retrovirus vectors, LNL6 and GlNa. One 
portion of the cells will be treated with growth factors and the other will remain 
untreated. Both portions of cells will be reinfused at the time of transplant. The time 
and persistence of engraftment will be determined. 
Dr. Miller said that the proposed protocol is similar to other marking protocols 
previously approved for the same laboratory. The investigators are competent and 
experienced. He recommended approval of this protocol. He noted that the 
Institutional Biosafety Committee (IBC) recommended Biosafety Level (BL) 2 physical 
containment for the retroviral vectors, but BLl is sufficient according to the NIH 
Guidelines. 
Review-Dr. Chase 
Dr. Chase recommended that a statistician should be consulted for data analysis and 
accurate determination of the growth pattern differences between treated and untreated 
cells across a heterogeneous pool of subjects. 
Review-Ms. Buc 
Ms. Buc commented on minor inconsistencies in the Informed Consent document as 
follows: (1) All items in the "statement of understanding" are not included in the 
Informed Consent document, and (2) the statement "I know my or my child's records will 
not be given to anyone outside the hospital unless I agree" is not necessarily true as 
these records could be subpoenaed. She commended the investigators for writing such 
an understandable Informed Consent document. 
Dr. Walters commented that this Informed Consent document could serve as a model for 
other investigators. He noted Ms. Meyers' written comments suggesting that 
recommendations for long-term follow-up and a request for autopsy should be included 
in the Informed Consent document. 
Ms. Buc said that the proposed study promises to definitively answer important questions 
regarding bone marrow engraftment and holds the promise for improving current therapy 
methods. 
Investigator Response-Dr. Heslop 
Dr. Heslop agreed to incorporate minor changes in the Informed Consent document 
suggested by Ms. Buc. 
Dr. Miller noted the IRB's provisional approval of the protocol pending RAC review. 
Are there other issues raised by the IRB that have not been addressed? Dr. Heslop 
answered that there are no outstanding issues; provisional approval refers to informing 
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