1. What levels of gene expression in 
non-human primate models must be 
achieved in order to offer 
reasonable hope of benefit to human 
patients? 
2 . To what extent must persistence of 
the added gene be demonstrated to 
offer a reasonable hope of benefit 
to human patients? 
3. Is a small amount of contamination 
(at a level of 0.1 percent) with 
replication-competent virus 
acceptable in the preparations 
which will be used to treat the 
bone marrow cells of patients? 
Dr. Walters also said the Anderson Group questioned whether 
trials with no adverse effects in non-human primates would be 
sufficient evidence to conclude that such preparations are 
unlikely to harm human patients. 
Dr. Walters said the subcommittee met on April 24, 1987, and 
discussed these questions with Dr. Anderson: and they decided to 
circulate the document to outside experts in basic and clinical 
sciences to gain their insight as to the data reported and issues 
raised in the document. Further, they decided the comments 
received from reviewers plus the preclinical data document will 
become part of a public record which will lead in the future to 
submission of a clinical gene therapy protocol through the 
subcommittee to the RAC. The subcommittee set a meeting for 
December 7, 1987, at which time the reviews and the preclinical 
document will be discussed as a central topic of the meeting. 
Mrs. Witherby then reviewed the draft of a document entitled 
"Gene Therapy for Human Patients" (tab 1308), which was drafted 
by six members of the subcommittee to help educate the non- 
scientific public on the subject of human gene therapy. She said 
the subcommittee had discussed the document. It suggested that 
after adoption by the subcommittee, the document be brought 
before the RAC, circulated for public comment, and eventual RAC 
approval. Furthermore, she said she was eager to use the 
document separately for educational purposes. 
She said the document is divided into four sections. The first 
section includes medical facts about genetic diseases, present 
efforts at treatment, and the possibility of treating a subset of 
these diseases with somatic cell gene therapy. The second 
section includes information on oversight and public involvement 
[46] 
Recombinant DNA Research, Volume 13 
