New Preclinical Study Shows Immunovaccine's DepoVax(TM)-Based Cancer Vaccine May Improve Efficacy of Checkpoint Inhibitors

HALIFAX, NOVA SCOTIA--(Marketwired - April 20, 2016) - Immunovaccine Inc. ("Immunovaccine" or the "company") (TSX:IMV)(OTCQX:IMMVF), a clinical stage vaccine and immunotherapy company, presented new preclinical data at the American Association for Cancer Research (AACR) Annual Meeting 2016. The investigators' findings showed that a combination immunotherapy using a DepoVax™-based vaccine could enhance the anti-tumor effects of a PD-1 blockade, controlling growth in advanced HPV-expressing tumors in animal models.

Investigators concluded that combining a DepoVax™-based vaccine with the chemotherapy metronomic cyclophosphamide (mCPA) increased PD-1 and PD-L1 in tumors, which in turn made them increasingly vulnerable to the monoclonal antibody treatment targeting these checkpoint inhibitors.

"Checkpoint inhibitors have shown tremendous promise in treating certain types of cancers, and our industry is now racing to discover and develop combination therapies to make these treatments effective across a broader range of patients," said Frederic Ors, Immunovaccine Chief Executive Officer. "This study shows how our DepoVax™-based vaccines can become an integral part of these therapies as they have the potential to increase the susceptibility of tumors to PD-1 blockades, even in tumors that typically do not respond to checkpoint inhibitor therapies. We are currently evaluating opportunities to pursue partnerships, leveraging our DepoVax™-based vaccines to increase the efficacy of the checkpoint inhibitors in development or currently on the market."

Presented as a poster at AACR 2016, the study evaluated the anti-cancer effects of a Depo-Vax-™ based vaccine combined with mCPA and a PD-1 blockade (either anti-PD-1 or anti-PD-L1) in a preclinical tumor model. The tumor model used in the study has a relatively low expression of PD-1 and PD-L1. The study treatment combination resulted in growth control of established tumors, even those that were not successfully treated with antibody monotherapy alone.

In addition to the efficacy findings, the study is the first to show how the combination of a DepoVax™-based vaccine, mCPA, and a PD-1 blockade can work synergistically to increase activation and clonal expansion of tumor-infiltrating T cells. Two key findings were:

1. Treatment with a DepoVax™-based vaccine and mCPA caused selective enrichment of antigen-specific CD8⁺ T cells, which increased immune responses.
   
   
2. Anti-PD-1 therapy can enhance the efficacy of vaccine immunotherapy by promoting the activity and expansion of antigen-specific T cells within the tumor microenvironment.
   
   

Investigators concluded that inoculation with the DepoVax™-based vaccine generated an influx of T cells into tumors, essentially priming the tumor for additional anti-cancer activity when combined with PD-1 blockade.

"The findings support our contention that stimulating high-quality T cell responses to the tumor is a key to inducing stronger clinical responses, particularly for those cancers that do not respond to PD-1 treatment alone," said Marianne Stanford, PhD, Immunovaccine Director of Research. "While we've always reasoned that our DepoVax™-based vaccines would work synergistically with blockade therapies, this study actually showed us how and why this happens. These findings provide us with a roadmap to inform our future clinical strategy for combining our DepoVax-based vaccines, including our DPX-Survivac vaccine candidate, with checkpoint therapies."

About DepoVax™

DepoVax™ is a patented formulation that provides controlled and prolonged exposure of antigens plus adjuvant to the immune system, resulting in a strong, specific and sustained immune response with the potential for single-dose effectiveness. The DepoVax™ platform is flexible and can be used with a broad range of target antigens for preventative or therapeutic applications. The technology is designed to be commercially scalable, with the potential for years of shelf life stability. Fully synthetic, off-the-shelf DepoVax™-based vaccines are also relatively easy to manufacture, store, and administer. This would enable Immunovaccine to pursue vaccine candidates in cancer, infectious diseases and other vaccine applications.

About Immunovaccine

Immunovaccine Inc. develops cancer immunotherapies and infectious disease vaccines based on the Company's DepoVax™ platform, a patented formulation that provides controlled and prolonged exposure of antigens and adjuvant to the immune system. Immunovaccine has advanced two T cell activation therapies for cancer through Phase 1 human clinical trials and is currently conducting a Phase 2 study with its lead cancer vaccine therapy, DPX-Survivac, in recurrent lymphoma. DPX-Survivac is expected to enter additional Phase 2 clinical studies in ovarian cancer and glioblastoma (brain cancer). In collaboration with commercial and academic partners, Immunovaccine is also expanding the application of DepoVax™ as an adjuvanting platform for vaccines targeted against infectious diseases. Immunovaccine's goal in infectious diseases is to out-license its DepoVax™ platform to partners to generate earlier revenues. For more information, visit www.imvaccine.com.

Immunovaccine Forward-Looking Statements

This press release contains forward-looking information under applicable securities law. All information that addresses activities or developments that we expect to occur in the future is forward-looking information. Forward-looking statements are based on the estimates and opinions of management on the date the statements are made. However, they should not be regarded as a representation that any of the plans will be achieved. Actual results may differ materially from those set forth in this press release due to risks affecting the Company, including access to capital, the successful completion of clinical trials and receipt of all regulatory approvals. Immunovaccine Inc. assumes no responsibility to update forward-looking statements in this press release except as required by law.