Abstract
Novel anti-cancer immune therapeutic strategies, like various new antibody formats and/or tumor vaccines, show promising results in patients. However, due to the “immune-escape phenomenon” driven by tumor-secreted Transforming Growth Factor-beta (TGF-beta), the host immune system of cancer bearing patients frequently fails to control tumor re-growth.
The RealTVac® approach aims at avoiding this “immune-escape phenomenon” by intratumoral inhibition of active TGF-beta isotypes while simultanously and synergistically inducing an efficient immune response by a highly potent combination of immune stimulating factors.
The synergistic effects of the proposed combination of a TGF-beta inhibitor with immunostimulating cytokines upon human immune cell activation are demonstrated in in-vitro experiments. Both, immune cell proliferation and tumor cell cytotoxicity were significantly enhanced. Initial experiments in a syngenic B16 melanoma xenograft model in immunocompetent mice indicate that the RealTVac® therapy of established subcutaneous B16 tumor xenografts reduced local tumor growth compared to untreated controls.
To summarize, the goal of the local application of RealTVac® is to allow the host immune system to scan in real-time all Tumor Associated Antigens (TAAs) being currently expressed by those tumor cells that are exposed to sufficient TGF-beta inhibition. The repetitive administration of the RealTVac® approach is furthermore expected to provide a continuous update of the immune response, reflecting the changing pattern of TAAs related to the dynamic intratumoral heterogeneity in malignant tumors.
Citation Format: Piotr Jachimczak, Andreas Mitsch, Achim Aigner. RealTVac, a novel strategy to treat advanced, late-stage tumors with real-time tumor vaccination. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 301. doi:10.1158/1538-7445.AM2015-301
- ©2015 American Association for Cancer Research.
Volume 75, Issue 15 Supplement
