Medical Record : Continuation Sheet for Consent to Participate in a Clinical Research Study 
Number ^Continuation: page 5 of 8 pages 
The potential complications relating to the use of the Ommaya reservoir are infection and bleeding. 
Every effort will be made to maintain sterility and prevent bleeding. 
Risk of the Vector/TK Gene Transfer: 
Even though the vector producing cells cannot grow and are considered harmless in humans, it 
is possible that events could occur within the cells that would permit the vector to grow and/or make 
the cells cancerous. Gene transfer using similar vectors has been used in adult and child patients. 
Since these experiments started in 1989, none of the more than 20 people who have received cells into 
which genes had been transferred by vectors has developed any problems related to the gene transfer 
method. We believe these vectors are safe and are not a threat to other people or to society. 
This method of treatment has 2 major potential problems. First, the vector may be passed into 
surrounding normal tissue in addition to tumor tissue. We have not found any evidence of problems 
in mice and rats due to the spread of vector to surrounding normal brain tissue or to other sites in the 
body. We believe that some of the surrounding blood vessel cells probably do have the vector, but 
the number is too small to result in significant adverse side effects. It is possible that bleeding and 
neurologic symptoms (headache, convulsions, stroke) may develop with Cytovene. 
Second, the vector producing cells might persist in your body and cause cancer or other 
diseases. We expect your immune system to reject (kill) the vector producing cells in 1-2 weeks. 
Thus, they should not be able to survive and grow in your body. In addition, we expect the Cytovene 
therapy will kill all cells with the vector, including the vector producing cells. Therefore, the vector 
producing cells should not survive and the insertion of the vector should not result in new cancerous 
cells, since we think all of the cells with the vector will be killed by Cytovene. Therefore, we feel that 
the risk of developing a new cancer is very small. 
Risk of Cytovene Therapy: 
Cytovene has been used extensively in humans to treat a number of infections including viral 
infections of the eye. We will be following the recommended dose for therapy that has been used to 
treat viral infections of the eye. The most commonly observed complication in people receiving 
Cytovene has been the development of decreased white blood cell and platelet counts. This could 
result in an increased risk of infection and bleeding. We will monitor these counts every other day 
(during Cytovene treatment) and the drug will be discontinued if the white blood count or platelet 
count drops significantly. Discontinuation of the drug results in normalization of the white blood cell 
and platelet numbers. Cytovene may cause permanent or temporary infertility and may be associated 
with birth defects. Therefore, women of childbearing age should use effective contraception during 
Cytovene therapy and men should use contraception during and for at least 90 days following 
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Recombinant DNA Research, Volume 17 
