M.J. Welsh and A.E. Smith, RAC Application 
Ad2-ORF6/PGK-CFTR 
Item 5 - Clinical Protocol 
Virus Replication. The Ad2-ORF6/PGK-CFTR viral construct has been rendered defective for replication 
by deletion of two important early genes Ela and Elb. The majority of the E4 region has also been 
deleted. However, it is possible that the virus will have a limited ability to replicate in human cells. 
Furthermore, under certain circumstances, the viral defect could be complemented. Such circumstances 
include coinfection with wild-type adenovirus or provision of El gene function by latent or residual 
adenovirus resulting from an earlier infection. Finally, epithelia might also provide normal cellular 
proteins with El -like functions that are able to complement the defective virus. 
Most of these possibilities seem remote. The likelihood of coinfection of treated cells with wild-type 
virus is minimized by prior screening of the patients and by treating only seropositive patients. 
Moreover, in the unlikely event that coinfection with wild type adenovirus did occur, Ad2-ORF6/PGK- 
CFTR is missing much of the E4 region and is unlikely to compete with wild-type virus. Thus, a wild- 
type infection would probably become self-limiting. 
There is also a possibility of recombination between wild-type virus and Ad2-ORF6/PGK-CFTR. 
Whether this occurred by legitimate or illegitimate recombination, three separate events would be required 
to produce replication competent progeny virus: First, insertion of the missing El gene, second, insertion 
of E4 sequences, third, deletion of DNA sequences to enable the resulting recombinant to become small 
enough to package its DNA. The most likely sequences to be deleted, compatible with retention of 
biological activity, would be some or all of the CFTR DNA. Growth of such a recombinant would 
probably be self-limiting and would be unlikely to lead to synthesis of CFTR fragments with any 
significant biological activity. 
Environmental Risks. There is a risk that the virus could be passed to another person. This could occur 
if a caregiver or visitor is exposed to the virus we apply to the patient or exposed to virus that has 
replicated in the patient As described immediately above, replication of Ad2-ORF6/PGK-CFTR in the 
patient is very unlikely. To minimize the risk of exposure to persons other than the participant the pauent 
will be kept in isolation for one day after vector administration. In addition, we are using relatively small 
amounts of the virus which will limit the risk that others will be exposed to the virus. Were 
environmental release to occur, the most likely virus involved would be wild-type adenovirus that had 
overgrown Ad2/PGK-CFTR-1 or a recombinant with no biological activity other than that associated with 
wild-type virus. 
Effects of Wild-tvpe Adenovirus 2 Infection. Potential effects of wild-type adenovirus 2 include 
symptoms of upper respiratory infection. Pharyngitis and conjunctivitis are known to be associated with 
adenovirus. Strains of adenovirus other than adenovirus 2 have been known to cause pneumonia, 
transient diarrhea and gastroenteritis. Rare problems associated with adenoviral strains include cystitis 
and keratoconjunctivitis. Such problems may be hazardous in immunocompromised hosts. The possible 
role of adenovirus in oncogenesis has been under investigation with no evidence to suggest a role for 
adenovirus in human oncogenesis. 
Potential Risks Associated with the Study Procedures. 
Nasal and Pharyngeal Swabs. Nasal and pharyngeal swabs can produce mild discomfort when they are 
taken, but there is no serious or long term risk. They are standard practices in clinical medicine. 
Biopsy of the Nasal Mucosa. Biopsy of the nasal epithelium will produce mild to moderate pain and 
discomfort. Pain and discomfort during the procedure will be minimized by use of local anesthesia. 
Subsequent use of analgesics will be allowed if needed. A small risk of bleeding or subsequent scar 
formation after the biopsy is possible as is expected for such a routine procedure. There is also a risk of 
infection. We will treat pain with analgesics and observe the area for bleeding or infection; if either 
should require it, we will administer appropriate treatment. 
Venipuncture. Venipuncture to obtain blood samples produces minimal risks that are well-known. 
Arterial Puncture. Arterial puncture includes the risk of bleeding, bruise formation, and pain at the time 
of the procedure. The procedure is standard and done frequently on outpatients. 
Pulmonary Function Tests. Pulmonary function studies are routine on outpatients with a variety of lung 
diseases. There are no anticipated short or long term risks. 
Recombinant DNA Research, Volume 18 
[873] 
