Abstract 1582: Therapeutic vaccine for pancreatic cancer

Abstract

Abstract Cadi-05 (Heat killed mycobacterium w) is a potent TLR 2 agonist and induces pure potent Th1 response. In advanced Non small cell lung cancer, Cadi-05 is found to potentiate efficacy of chemotherapy (Paclitaxel + Cisplatin) with improvement in response rate and overall survival in a randomized controlled clinical trial. Cadi-05 is also a potent vaccine adjuvant for prophylactic vaccines providing faster, higher and sustained antibody titers in animals and humans. The therapeutic vaccine for pancreatic cancer, with killed pancreatic cancer cells as an antigen with Cadi-05 as an adjuvant was evaluated for its ability to induce cell mediated immune responses (by ELISPOT for IFN - α, IL-2 and Granzyme B) and effector function (By BrDu incorporation). The vaccine made using Mia PaCa-2 cell line induced cell mediated immune responses against the Mia PaCA-2 as well as against the other cell lines (Panc-1, ASPC-1, SW-1990). The vaccine also generated effector function of similar magnitude against all four cell lines. Effect of vaccine on tumor size and survival following intradermal immunization was also studied. For evaluating efficacy, C57BL/6 BYJ mice were injected Pan-02 cells (1x106) subcutaneously for developing pancreatic cancer model. At day 10 post tumor induction tumor size achieved was∼200-225 mm3. Mice were randomized to receive vaccine or placebo (18 mice each) on day 10. No other therapy was used in the experiment. In Vaccine arm tumor regression was seen in 61% of animals before progression. Tumor regression was not seen in placebo arm. Tumor progression was found to be slower in vaccinated animals with mean tumor size 35% and 59% of placebo arm on day7 (633 mm3 vs. 223 mm3) and day 12 (740 mm3 vs. 437 mm3) respectively resulting in survival benefit of 36% on day 40 following immunisation. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1582. doi:1538-7445.AM2012-1582