Allogeneic Gene-Modified Tumour Cells in Metastatic Kidney Cancer. Report II

In a limited study, comprising only ten patients, we have previously reported that allogeneic irradiated RCC-cell-line cells, engineered to produce IL-2 (ACHN-IL-2), admixed with autologous metastat- ic formalin-treated tumour cells were used to vaccinate MRCC patients in progression of disease and also receiving IL-2 immunotherapy. The cells, admixed to autologous TC, were administered subcutaneously. We now report an extended study on thirty patients and one hundred thirty-one controls. Patients received 4n20 injections (mean 10 ± 4), containing an average of 92 × 10 6 ± 45 × 10 6 ACHN-IL-2 transfected cells (a mini- mum of 25 × 10 6 , and a maximum of 200 × 10 6 ). Autologous TC, admixed to allogeneic, were also administered by 4n16 s.c. injections (mean 7 ± 3), i.e. a total of 12 × 10 6 n160 × 10 6 cells. Vaccination was administered during 73n1451 (307 ± 316) days, and the follow-up continued for 1122 ± 1240 days (106n5137). Throughout this period, the patients continued receiv- ing the previously set immunotherapy treatment. No adverse side effects related to the treatment were noticed. One complete and four partial tumour responses were observed, as well as nine cases of stable disease. Thirteen patients died in the treated group (43%) and 63 (44%) in the control group. Responding patients resumed progression in 4n11 months and died 18 and 36 months after beginning the vaccine therapy. The Gehan Wilcoxonis test showed a significantly (P < 0.01) better survival in the vaccinated patients com- pared to that of the controls. Thus, we confirm, in an increased number of patients and an extensive follow- up, that our vaccination protocol is safe, devoid of adverse side effects, and promising.