TKSTM is our adjuvant treatment that combines our gene therapy, using the Herpes simplex virus (HSV) thymidine kinase gene, with standard surgery for the treatment of cancers.  Our pre-clinical findings demonstrate that combined therapy resulted in delayed tumor recurrence, improved survival, and suppression of pre-established lung metastases. Histologic analysis also confirmed both a delay in recurrence and a qualitative difference in recurrent tumor in the treatment group as compared to the controls.  The histological differences in the tumors have been confirmed in an early Phase I studies.  In these first clinical studies the tumors were treated with AdV-tk followed by prodrug prior to radical prostatectomies.  In another clinical scenario primary tumors will be surgically resected and adjuvant gene therapy will then be delivered into the surgical wound sites.  The two approaches may also be combined.

• Preclinical data indicate that the combination of surgical resection plus adjuvant gene therapy can provide therapeutic benefits without increased toxicity.
• In these studies combination therapy significantly delayed recurrence and prolonged survival.
• Histopathologic analysis reveals both a significant reduction in tumor volume and qualitative differences in recurrent tumor between the treated and non-treated groups.
• Antimetastatic activity is clearly demonstrated by the significant reduction in the number of established lung metastases.
• TKSTM has not shown additional toxicity in early clinical studies.