A renal cancer cell (RENCA) vaccine successfully inhibits tumor induction and progression in a murine renal cancer model

2617 Background: Recently, we have demonstrated that an adjuvant renal tumor cell vaccine (aTL) is effective in reducing the risk of tumor progression in patients with renal cell carcinoma (RCC) following radical nephrectomy. However, this approach has not been confirmed in an animal model. In a murine renal cancer (RENCA) model we investigated the impact of a renal cancer cell vaccine (RENCA vaccine) on tumor induction and progression. Methods: There were 7 groups with 12 female BALB/c mice in each group. All animals received 5 vaccinations in 3-week intervals before tumor induction (subcapsular injection of 5x105 RENCA cells) and one vaccination 14 days afterwards. In each 3 groups mice received a RENCA vaccine (lysate of 1x106, 5x106 or 1x107 RENCA cells, production process comparable to that of aTL applied in humans) with or without co-incubation using Interferon-gamma. The control group was treated with solvent only. All mice were sacrificed on day 21 after tumor induction. Study criteria were animal welfare and growth, volume and weight of the tumor bearing kidney and number of lung metastases. Additionally, the induction of cytotoxic T cells was determined by a 51chromium-release assay. Results: Mice in the vaccine groups did not show relevant side effects from vaccination. After tumor induction body weight decreased in mice from the control group whereas it remained stable in the vaccine groups. All animals in the control group developed a renal tumor while in the vaccine groups 65/72 animals did not. The mean number of lung metastases was 100 (range 3–750) in the control group compared to 4 (range 0–196) in the vaccine groups. The 51chromium-release assay confirmed a significant activity of splenocytes from mice in the vaccine groups against RENCA cells compared to mice in the control group. Conclusions: We were able to demonstrate antitumor effects from treatment with a RENCA vaccine in a RENCA model. These findings may confirm the results from a recent phase III trial showing that an adjuvant renal tumor cell vaccine (aTL) is effective in reducing the risk of tumor progression in patients with RCC following radical nephrectomy. No significant financial relationships to disclose.