Allogeneic gene-modified tumour cells in metastatic kidney cancer. Preliminary report

An allogeneic irradiated RCC cell line, engineered to produce IL-2 (ACHN-IL-2), admixed with autologous metastatic formalin-treated tumour cells, was used to vaccinate ten MRCC patients in progression of disease in spite of IL-2 immunotherapy. The cells were administered subcutaneously and/or intra-tumourally. Sixty-four MRCC patients in progressive disease, not treated by vaccination but receiving similar IL-2 immunotherapy, were considered as the control group. Patients received 4-16 injections (mean 9 +/- 4), containing an average of 10.6 x 10(7) +/- 7.7 x 10(7) ACHN-IL-2-transfected cells (a minimum of 4 x 10(7), and a maximum of 31 x 10(7)). Four patients also received intra-tumour injections. Vaccination was administered during 30-418 days, and the follow-up continued for 649 +/- 353 days (190-1342). Throughout this period, the patients continued receiving the previously set immunotherapy treatment. No adverse side effects related to the treatment were observed. One complete and one partial tumour response were observed, as well as two stable and one no-relapse disease. All but one patient died. Responding patients resumed progression in 4-11 months and died 18 and 36 months after beginning the vaccine therapy. In spite of the small number of treated patients, Wilcoxon's test showed a significant (P < 0.05) improvement of the survival in the vaccinated group compared to that of the control. The described vaccination protocol seems safe, devoid of adverse side effects and promising. It warrants further investigation.