Abstract 3686: Generation of an off-the-shelf cell-based platform (PDC-vac) for active antitumor immunotherapy

Abstract The development of efficient vaccines for the treatment of cancers in combination or not with other agents such as checkpoint inhibitors represents a major public health issue but remains a challenge. A dozen of vaccine drug products is expected to be marketed in the next few years. In this context, off-the-shelf and potent platforms are more attractive than individualized vaccines that are tailored to each patient in many aspects. We have recently developed a new cell-based vaccine approach named PDC*vac (formerly GeniusVac). This cell-based vaccine was developed thanks to the establishment, from leukemic PDC, of unique human PDC line (PDC*line). We have previously shown the potential of peptide-loaded PDC*line to induce strong and fully functional HLA-A*02:01-restricted anti-tumor immunity in vitro and in vivo (Aspord et al, 2010, 2012). PDC*mel (GenusVac-Mel4), our first product is currently developed for the treatment of melanoma patients (NCT01863108). The high efficiency of PDC*vac renders the strategy very attractive for further clinical developments in active immunotherapy field. Our aim is to optimize PDC*vac technology by passing use peptides and render the vaccine easier to manufacture. We engineered our PDC*line using retrovirus to force the endogenous expression of one or more tumor or viral antigenic peptides or whole tumor/viral proteins (gp100, tyrosinase, Melan-A, Mage-A3, CMVpp65, flu, EBV) that broaden the panel of antigens presented. Data obtaining with different polypeptide and protein gene coding constructions and the expansion of multi-specific antigen-specific T-cells at the same time will be presented. Moreover, we will present how we succeed to obtain 100% of efficacy in antigen presentation by the PDC*line engineered to express tumor proteins or polyepitopes. We have validated the use of retrovirus constructs to create a new generation of an “off-the-shelf” cancer vaccines highly potent to stimulate antitumor-specific T-cells. Citation Format: Joel Plumas, Kevin Lenogue, Alexandre Walencik, Jean-Paul Molens, Laurence Chaperot, Martin Pule. Generation of an off-the-shelf cell-based platform (PDC-vac) for active antitumor immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3686. doi:10.1158/1538-7445.AM2017-3686