Patients with radiorecurrent prostate cancer have few viable treatment options, both in terms of efficacy and morbidity. Local therapies fail even in highly selected patients due to locally advanced disease, microscopic metastases, and a worsening of the biology of cancer cells. Furthermore, attempts at salvage local treatments have the complications of incontinence, impotence and in some cases unremitting penile pain. Pre-clinical studies in a mouse model of prostate cancer have noted the potential benefit of adenovirus-mediated gene therapy to deliver IL-12 in this clinical scenario. This treatment was able to significantly growth suppress the injected tumor to prolong survival and reduce the number of pre-established metastases. The mechanisms underlying this activity involved both innate immunity (neutrophils and natural killer \[NK\] cells) and acquired immunity ( T cells) and enhanced expression of Fas to further sensitize Fas/Fas ligand (FasL) killing.
This is a Phase I study. Therefore, the primary objective is finding the Maximum Tolerated Dose. Within this realm will be monitoring of pro-inflammatory cytokines. Secondary aspects will involve correlating important mechanisms identified in the pre-clinical model: induction of T cells.
