BETHESDA, Md. -- The NIH's Recombinant DNA AdvisoryCommittee (RAC) on Friday unanimously approved a thirdprotocol on gene therapy for cystic fibrosis (CF), this onesponsored by Genzyme Corp. (NASDAQ:GENZ) of Cambridge,Mass., and the Howard Hughes Medical Institute at Universityof Iowa Medical School. The principal investigator is Iowa'sMichael Welsh.
RAC approved two other CF gene therapy protocols lastThursday, one headed by Ronald Crystal of the National Heart,Lung and Blood Institute, and the other by James Wilson fromthe University of Michigan Medical Center.
The goals of all three protocols are to assess safety and efficacy,and to determine an effective dose. But this study takes a moreconservative approach than the first two in that it targets thecystic fibrosis transmembrane conductance regulator gene(CFTR) to nasal epithelium rather than lung tissue.
This is safer for patients because the tissue's health can easilybe monitored on a daily basis without the need forbronchoscopy. Easy access to the tissue is, of course,advantageous to the researchers as well. Additionally, onlythree research subjects will be used.
One aspect of the trial protocol that concerned RAC memberswas that payment for participation, $75 per day, "might inducesomeone to do something they are frightened of," said AbbeyMeyers, an ad hoc consultant to the committee who is head ofthe National Organization for Rare Disorders.
Welsh explained that his university's institutional review board(IRB) had discussed this issue, and concluded that the fee wasreasonable compensation for absence from one's normal dailyactivities. Robertson Parkman, head of the division of researchimmunology, bone marrow transplantation at Children'sHospital of Los Angeles, agreed that most universities wouldprefer to offer such compensation to human subjects, but theycan't afford it.
RAC also raised the possibility that, once gene therapy for CFbecomes widespread, recombinant adenovirus-CFTR genesmight escape into the environment. "I would bet money thiswould not cause a problem if released in the environment,"said RAC member A. Dusty Miller of the Fred HutchinsonCancer Research Center in Seattle. "The situation would bedifferent with something like diphtheria toxin or an oncogene.There is evidence that CFTR is not toxic."
The RAC adopted Georgetown University bioethicist LeroyWalters' recommendation that it be made clear in the title andintroduction to the informed consent form that participation inthe study would provide no medical benefit.
-- David C. Holzman Special to BioWorld
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