GeoVax, ViaMune to partner on cancer immunotherapy program

Both companies’ products target an abnormal form of the autologous cell surface-associated protein, Mucin 1 (MUC1), which is over-expressed in the majority of known tumor types.

Due to overexpression and/or aberrant glycosylation of MUC1, this “tumor-associated antigen” (TAA) is often recognized as abnormal by patients’ immune system but is not sufficiently immunogenic to trigger an effective immune response needed to control or eliminate tumors. Therefore TAAs must be presented to the body in a different form, or in a different way, to enlist the immune system in fighting the cancer.

The collaboration will assess each companies’ vaccine platform, separately and in combination, with the goal of developing a tumor MUC1 vaccine that can produce a broad spectrum of anti-tumor antibody and T cell responses.

The resulting MUC1 vaccine will be combined with immune checkpoint inhibitors (CPIs) as a novel vaccination strategy for cancer patients with advanced MUC1+ tumors.

CPIs directed against CTLA-4, PD-1 and/or PD-L1 have led to dramatic clinical responses in patients with advanced cancers yet only 20-40% of patients benefit. Patients that do not respond to CPI therapy do not produce on their own the levels of cytotoxic T lymphocytes (CTLs) needed for efficient killing of tumor cells.

GeoVax and ViaMune will combine efforts in order to produce efficacious levels of CTLs in a greater percentage of patients, thus enabling more patients to benefit from CPI therapy.

GeoVax’s immuno-oncology program is based on its Modified Vaccinia Ankara (MVA) Virus-Like Particle (VLP) platform, which generates noninfectious VLPs in the individual being vaccinated. Gene sequences of target antigens can be recombined into the MVA genome in order to drive expression of those target antigens by MVA in infected cells.

In addition, GeoVax incorporates into the viral genome other sequences that simultaneously facilitate (1) the budding of VLPs from the membranes of infected cells, and (2) the incorporation of the target antigen into these VLPs. Thus infected cells produce the antigen internally and additionally bud particles that display natively-folded target antigen on their membrane surfaces in a form that mimics viruses.

In this way, VLPs are produced in the host by host cells and thereby provide two pools of antigen as targets for the immune response: virus-infected cells and released VLPs. This mimics a natural infection, triggering the body to produce a robust and durable immune response with both antibodies and T cells.

ViaMune is focused on development of next generation immunotherapy products that are simple in execution yet enable robust immune responses with minimal off-target effects.

ViaMune’s lead cancer vaccine, MTI, has demonstrated in mouse tumor models induction of tumoricidal cytotoxic T lymphocytes (CTLs) and antibodies and the ability to prevent tumor growth. MTI is a product of ViaMune’s patented vaccine platform which combines into a single fully synthetic molecule the glycopeptide structure of disease-associated antigens and powerful immune stimulants.

When initial experiments are successful, GeoVax and ViaMune have agreed to contribute their respective intellectual property to a “to-be-formed” joint venture for further development and commercialization. The goal of the joint venture would be to develop vaccine products for the treatment of multiple cancer indications in conjunction with CPIs.

GeoVax president and CEO Robert McNally said: “We are pleased to enter into this collaboration with ViaMune. Our respective propriety programs are distinct, with different mechanisms of action; but we share the same targets and clinical strategy. Our research collaboration and possible joint venture going forward will provide multiple “shots on goal” with potential synergies between our technologies. Our approach may be useful for a number of solid tumors such as non-small cell lung cancer, colorectal carcinoma, breast cancer and renal cell carcinoma. We are excited about the potential for both of our respective programs.”

ViaMune president and CEO Alex Harvey said: “Building on advances in the fields of immunotherapy and checkpoint inhibition, ViaMune is developing a new class of therapeutic cancer vaccines targeting precisely engineered cancer-specific aberrantly glycosylated proteins.

“Our collaboration with GeoVax targeting MUC1 not only enhances the likelihood of success for cancer vaccine development against this target but provides a basis for potentially expanding a clinical product development pipeline from both within and beyond cancer.”