Immunovaccine Shows Pronounced and Persistent T Cell Immune Responses in DPX-Survivac Cancer Vaccine Study Presented at American Society of Clinical Oncology (ASCO) Meeting
Immune responses consistent with those required for cancer vaccines to potentially impact disease progression; adds to growing excitement in field of cancer immunotherapy
Poster is one of few selected for detailed discussion at ASCO by Dr. Jedd Wolchok, top cancer immunotherapy thought leader
Halifax, Nova Scotia; June 3, 2013 – Immunovaccine Inc. ("Immunovaccine" or the "Company") (TSX-V: IMV), a clinical stage vaccine company, presented positive results from a Phase I clinical study of DPX-Survivac, one of the Company's two clinical stage cancer vaccines, this weekend at the American Society of Clinical Oncology (ASCO) 2013 Annual Meeting. In a poster presentation at the conference, Immunovaccine highlighted study results that showed ovarian cancer patients treated with DPX-Survivac combined with low dose oral cyclophosphamide experienced pronounced and persistent T cell immune responses against survivin, a protein strongly associated with several tumor types. The company believes that these immune responses are consistent in profile to those necessary from a cancer vaccine to potentially impact disease progression. These study results were further discussed by Dr. Jedd Wolchok of Memorial Sloan-Kettering Cancer Center, a top thought leader in the area of cancer immunotherapy, at the poster discussion session that followed.
The Phase I study evaluated DPX-Survivac in combination with a maintenance low dose oral cyclophosphamide in ovarian cancer patients who have responded favorably to a standard of care platinum-based chemotherapy. The dose of cyclophosphamide was designed to have an immune modulation rather than a chemotherapeutic effect. Patients were enrolled in a non-randomized dose escalation fashion to receive three doses of DPX-Survivac alone or the vaccine along with cyclophosphamide. Patients receiving the combination treatment received one of two vaccine doses to evaluate a dose response to the vaccine.
A detailed study analysis showed that patients receiving the highest dose of DPX-Survivac demonstrated significantly higher survivin specific immune responses that were produced following one or two vaccinations and sustained after the third vaccination for at least three months. The durable systemic T cell response consisted of central and effector memory CD8 positive T cells that were of sufficient magnitude to be detected in peripheral blood without additional in vitro amplification. Persistent circulating memory CD4 positive and late differentiated CD8 positive T cells were also detected. Results were confirmed using multiple immune monitoring assays, including ELISpot, tetramer analysis and multiparametric immune cell staining.
The combination of DPX-Survivac and oral cyclophosphamide was generally well tolerated with no significant systemic adverse events. The most commonly reported adverse events were injection site reactions which were most prominent after repeated immunizations in patients receiving the highest dose of DPX-Survivac with cyclophosphamide. It is important to note that these patients receiving the highest DPX-Survivac dose also presented the strongest immune responses during the study.
"The high magnitude of persistent T cell immunity against survivin achieved in this study validates our concept of combining DPX-Survivac with oral cyclophosphamide," said Marc Mansour, chief science officer of Immunovaccine, who presented the data during the ASCO poster session. "Just as importantly, these T cells have the activation profile that therapeutic vaccines must achieve to potentially influence disease progression. As a result, we have a solid foundation to move our vaccine strategy forward into a randomized Phase II study."
DPX-Survivac consists of survivin-based peptide antigens formulated in the DepoVax™ adjuvanting platform. Survivin has been recognized by the National Cancer Institute (NCI) as a promising tumor-associated antigen (TAA) because of its therapeutic potential and its cancer specificity. Survivin is broadly over-expressed in multiple cancer types in addition to ovarian cancer, including breast, colon and lung cancers. Survivin plays an essential role in antagonizing apoptosis, supporting tumor-associated angiogenesis, and promoting resistance to various anti-cancer therapies. Survivin is also a prognostic factor for many cancers and it is found in a higher percentage of tumors than other TAA's.
The DPX-Survivac vaccine is thought to work by eliciting a cytotoxic T-cell immune response against cells presenting survivin peptides on HLA class I molecules. This targeted therapy attempts to use the immune system to search actively and specifically for tumor cells and destroy them. Survivin-specific T-cells have been shown to target and kill survivin-expressing cancer cells while sparing normal cells.
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 capability for single-dose effectiveness. The DepoVax™ platform possesses impressive flexibility, allowing it to work with a broad range of target antigens in various therapeutic applications. The technology is also commercially scalable, with potential for years of stability and ease of use in the clinic.
Immunovaccine Inc. applies its novel adjuvanting platform to the development of vaccines for cancer therapy, infectious diseases and animal health. The Company's DepoVax™ platform is a patented formulation that provides controlled and prolonged exposure of antigens plus adjuvant to the immune system. Immunovaccine has advanced two DepoVax™-based cancer vaccines into Phase I human clinical trials. The Company is also advancing a broad infectious diseases pipeline including vaccines in such indications as malaria, respiratory syncytial virus (RSV) and anthrax. In addition to the Company's human health vaccine strategy, it continues to capture value from animal health vaccine applications. Immunovaccine has key partnerships in the animal health sector including an agreement with Zoetis (formerly Pfizer Animal Health). Connect at www.imvaccine.com.
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.
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Dr. Marc Mansour, Chief Science Officer, Immunovaccine, Inc.
T: (902) 492-1819 E: [email protected]
Tim Brons, Vida Strategic Partners (media)
T: (415) 675-7402 E: [email protected]