WASHINGTON _ The National Institutes of HealthRecombinant DNA Advisory Committee (RAC) hasapproved clinical testing of GenVec Inc.'s newadenovirus-based gene therapy for colon cancer.

Before the end of 1995, clinical trials are expected to startat two New York hospitals under the supervision ofRonald Crystal, who forged his reputation in cysticfibrosis gene therapy. Crystal is chief of the division ofpulmonary and critical care medicine at Cornell MedicalCenter in New York.

The clinical trial involves use of an adenovirus vectormodified to carry the cytosine deaminase gene. Onceadministered directly to a hepatic tumor, the geneexpresses an enzyme that converts 5-fluorocytosine, anorally administered antifungal agent, into a potentantitumor agent, 5-fluorouracil, now considered the drugof choice to treat hepatic cancer.

Responding to concerns recently voiced that gene therapytrials have been inadequate, Rockville, Md.-basedGenVec's president, Thomas D'Alonzo told BioWorldToday that "some manufacturers made a dash to the clinicin order to support fundraising. But we have tried to beconservative in the design of the vector in order to getinformation about its utility."

The following protocols also were approved by the RACadvisory panel:

* A Phase I study of recombinant adenovirus vector-mediated delivery of an anti-erbB-2 single chain (sFv)antibody gene for previously treated ovarian andextraovarian cancer patients, submitted by David Curieland Ronald Alverez, University of Alabama,Birmingham.

* Arterial gene transfer for restenosis, submitted byJeffery Isner, Tufts University School of Medicine,Boston.

* Gene therapy for the treatment of advanced prostatecancer by in vivo transduction with prostate-targetedretroviral vectors expressing antisense c-myc RNA,submitted by Mitchell Steiner and Jeffery Holt,Vanderbilt University School of Medicine, Nashville.

* Phase I study of gene therapy for malignant gliomasinvolving interleukin-4 gene-modified autologous tumorto elicit an immune response, submitted by MichaelBozik, Mark Gilbert and Michael Lotze, University ofPittsburgh Cancer Institute, Pittsburgh.

* Phase I study to evaluate the safety of cellular adoptiveimmunotherapy using autologous unmodified andgenetically modified CD8+ HIV specific T cells in HIVseropositive patients, submitted by Stanley Riddell, FredHutchinson Cancer Research Center, Seattle.

The committee deferred action on a Phase I study of E1Agene therapy for patients with metastatic breast or ovariancancer that overexpress HER-2/neu because of concernsabout the adequacy of informed consent procedures. Thisprotocol was developed by researchers at MD AndersonCancer Center, Houston. n

-- Michele L. Robinson Washington Editor

(c) 1997 American Health Consultants. All rights reserved.