OncoSec Medical and Plexxikon Collaborate to Explore Combination Immunotherapy in Preclinical Tumor Studies

SAN DIEGO-- OncoSec Medical Inc. (OTCQB: ONCS), a company developing DNA-based intratumoral cancer immunotherapies, today announced a preclinical collaboration with Plexxikon Inc., a member of the Daiichi Sankyo Group and leader in the discovery and development of novel small molecule pharmaceuticals, to test the combination of Plexxikon's selective CSF-1R inhibitor with OncoSec's Immunopulse pIL-12.

OncoSec's Chief Scientific Officer, Robert H. Pierce, M.D., said: "Plexxikon is on the cutting edge of developing potent, highly-selective small molecule inhibitors of CSF-1R, a key cell surface receptor, which controls macrophage development and function. Intratumoral macrophages and other related cell types, like myeloid-derived suppressor cells, can be strongly immunosuppressive and block anti-tumor immunity. Given our understanding of IL-12 as a potent driver of immunogenicity and tumor-infiltrating lymphocytes (TILs) and the potential role of tumor-resident myeloid cells in suppressing the anti-tumor effects of TILs, we hypothesize that blocking CSF-1R with Plexxikon's selective CSF-1R inhibitor will lead to synergistic effects in the syngeneic B16.F10 melanoma mouse model."

Mai H. Le, M.D., OncoSec's Chief Medical Officer, commented: "Combination immune therapies, whether small molecules or biologics, will be the norm in the future. There is already considerable discussion in the oncology community regarding the need to find a rational approach to guide immune-focused combinations in the clinic. These initial studies are designed to test the rationale of our combination approach."

Interleukin-12 (IL-12) is an inflammatory cytokine that is believed to be a master regulator of the immune system, and is important in the up-regulation of both the innate and adaptive immune responses. IL-12 is a key driver of the cascade of biological events which ultimately lead to T-cell-specific killing of cancer cells. Moreover, cytokines and chemokines induced by this pathway also increase the recruitment of inflammatory T-cells into tumors.

ImmunoPulse is a proprietary investigational electroporation device that delivers plasmid IL-12 DNA directly into tumors. By locally delivering and expressing IL-12, ImmunoPulse drives a strong anti-tumor immune response, which can lead not only to local tumor regression, but also systemic anti-tumor responses, while avoiding toxicities caused by systemic administration of IL-12. Recent interim data from OncoSec's ongoing Phase II clinical study in melanoma have demonstrated that local delivery of IL-12 by electroporation increases the production of cytokines like IFN-γ, resulting in increased expression of genes related to the processes required for cytotoxic CD8+ T cells to recognize and kill cancer cells.

About PLX's highly-specific small molecule inhibitors of CSF-1R

Plexxikon is currently exploring the role of CSF-1R-targeted immune therapy as a sensitizer to chemo- and radiation-therapy, in addition to its potential to augment response to complementary immunotherapies.

About OncoSec Medical

OncoSec Medical Inc. is a biopharmaceutical company developing its investigational ImmunoPulse intratumoral cancer immunotherapy. OncoSec Medical's core technology is designed to enhance the local delivery and uptake of DNA IL-12 and other DNA-based immune-targeting agents. Clinical studies of ImmunoPulse have demonstrated a favorable safety profile and preliminary evidence of anti-tumor activity in the treatment of various skin cancers, as well as the potential to initiate a systemic immune response without the systemic toxicities associated with other treatments. OncoSec's lead clinical program evaluating ImmunoPulse for the treatment of metastatic melanoma is currently in Phase 2 development, and is being conducted in collaboration with several prominent academic medical centers. As the company continues to evaluate ImmunoPulse in its current indications, it is also focused on identifying and developing new immune-targeting agents, investigating additional tumor indications, and evaluating combination-based immunotherapy approaches. For more information, please visit www.oncosec.com.

Laura Colontrelle-Radocaj
Dian Griesel Int'l 
New York, NY
P: 212-825-3210