Addition of adenoviral vector targeting of chemotherapy to the MUC-1/ecdCD40L VPPP vector prime protein boost vaccine prolongs survival of mice carrying growing subcutaneous deposits of Lewis lung cancer cells.

We studied the effect of adding chemotherapy or vector targeted chemotherapy to the administration of an Ad-sig-hMUC-1/ecdCD40L adenoviral vector prime-hMUC-1/ecdCD40L protein boost cancer vaccine (designated hMUC-1/ecdCD40L VPPP vaccine), which were administered to test mice 10 days following subcutaneous (s.c.) inoculation of 500,000 Lewis Lung Carcinoma cells, at a time when the average volume of the s.c. tumors was 50 cu mm. The survival of hMUC-1/ecdCD40L VPPP vaccine-treated mice was twice as long as untreated mice. Addition of vector-targeted chemotherapy (AdCMVCDIRESE1A/5FC) to the hMUC-1/ecdCD40L VPPP vaccine 10 days after tumor inoculation significantly (P=0.0062) prolonged the survival of the test mice over administration of the hMUC-1/ecdCD40L VPPP vaccine alone or the control mice (P<0.00001). Interestingly, the combination of the AdCMVCDIRESE1A/5FC vector-targeted chemotherapy to the hMUC-1/ecdCD40L VPPP vaccine decreased the levels of CD44(+)CD24⁻ cells in s.c. deposits of the human MUC-1-positive Lewis Lung Cancer cell line (LL2/LL1hMUC-1) by 20 fold. These results suggest that the addition of vector-targeted chemotherapy to an adenoviral-based cancer vaccine is a strategy that deserves further testing.