This treatment also showed promise in preventing the growth of tumors even when administered 3 days after their implantation. However, it was not effective in eliminating them. Tissue biopsies were obtained from 10 cancer patients and cultured in vitro. These cells were than transfected with GM-CSF, irradiated, and readministered into the patients.
Preliminary results appear promising.
Combination Transfection of GM-CSF and a Second Gene. Recently, this treatment scheme was modified to insert GM-CSF and a second gene into cancer cells and these were irradiated and injected into mice. Similar to the transfection of GM-CSF, this treatment was effective at preventing the establishment of tumors when given prophylactically. However, unlike transfection with GM-CSF alone, transfection with two different cytokine genes was also effective at eliminating tumors once they are established.