ask to include it if it proves more effective than previous 
vectors in the future. 
The third amendment to the protocol is the delivery of 
recombinant genes using a catheter. This modification was 
proposed in our previous trial as a minor amendment for one 
patient in the protocol with a pulmonary metastases. This 
treatment was well-tolerated by the patient. No complications or 
toxicities were noted (summarized in Section 13, Preliminary 
Data, Table 3) . In this trial, we propose to analyze the 
toxicity associated with catheter-based gene delivery separately, 
since the toxicities of this procedure may differ from direct 
intratumor injection. This intervention provides the ability to 
transduce a larger percentage of cells within the tumor 
microcirculation in order to achieve greater efficacy of gene 
expression, at the same time minimizing the potential for 
inadvertent microscopic seeding of tumor cells to distant sites. 
Because this approach is not always feasible, we have also 
elected to continue the direct intratumoral injection approach. 
Finally, we have shown previously that this method of direct gene 
transfer is applicable to different tumor cell types. 
Particularly, for the in vivo catheter delivery, it may be 
appropriate to utilize this approach on malignancies other than 
melanoma. We therefore would like to maintain the option to 
treat other human cancers, for example, colon carcinoma, renal 
cell carcinoma, or breast cancer, in this study. These cancers 
would most likely be treated by catheter delivery. 
Recombinant DNA Research, Volume 17 
[695] 
