and c) be a means to spread the retroviral vector genes to other tissues in the 
patient's body. 
In the total absence of replication-competent virus, productive 
recombination should occur rarely and the risk should be sufficiently small so 
that the patient need not be isolated. Levels of helper virus below a given 
threshold will probably also be safe. But we do not know at present what that 
threshold level would be. Iji vivo safety experiments with the vector in 
monkeys need to be performed prior to gene therapy in humans. In addition, 
continued surveillance of monkey and human recipients for viremia or antibody 
production should be performed on a long term basis. Should evidence of active 
viral Infection occur, the risk to the general public would need to be 
reassessed. Since the actual safety of the procedure can only be postulated, 
the recipients of gene therapy probably should refrain from blood and organ 
donations. 
5. Qualification of Investigators, adequency of laboratory and 
clinical facilities 
Indicate the relevant training and experience of the personnel 
who will be Involved In the precllnlcal studies and clinical 
adminl strati on of gene therapy. In addition, please describe 
the laboratory and clinical facilities where the proposed study 
will be performed. 
Deferred 
a. What professional personnel (medical and nonmedical) will be 
Involved In the proposed study? What are their specific 
qualifications and experience with respect to the disease to be 
treated and with respect to the techniques employed In 
molecular biology? Please provide curricula vitae (see Section 
III-E). 
Deferred; see curricul urn vitae in Appendix C. 
b. At what hospital or clinic will the treatment be given? Which 
facilities of the hospital or clinic will be especially 
Important for the proposed study? Will patients occupy regular 
hospital beds or clinical research center beds? Where will 
patients reside during the follow-up period? 
Recombinant DNA Research, Volume 12 
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