VAX014 is a novel rBMC-based oncolytic immunotherapy designed to have distinct advantages over traditional and emerging oncolytic virotherapies. Vaxiion is leveraging these advantages to develop VAX014 as a best-in-class locally administered oncolytic therapy. The advantages of VAX014 over currently available oncolytic viral agents stem primarily from our novel approach to oncolysis in combination with a more immunogenic vector that has limited vulnerability to the innate immune system following local administration. With respect to oncolysis, VAX014 is highly differentiated and improved from oncolytic viral therapies by virtue of the fact that VAX014 delivers a pre-formed oncolytic protein toxin to facilitate oncolysis. This novel oncolytic protein, called perfringolysin O (PFO), works immediately upon intracellular release from VAX014 (complete oncolysis occurs within 1 hour in vitro). This is in stark contrast to oncolytic viral therapies, which are dependent upon successful completion of the viral lifecycle to exert their oncolytic mechanism. Paradoxically, viral replication and completion of the viral lifecycle are negatively impacted by a potent innate antiviral response after administration. Unlike oncolytic viruses, VAX014 does not rely on replication to initiate oncolysis and circumvents the innate antiviral response altogether. Equally important, the rapid oncolytic action of VAX014 instead ensures the presence of tumor antigens at the height of the innate response.
VAX014's ability to specifically target both alpha3beta1(α3β1) and alpha5beta1 (α5β1) integrins facilitates broad spectrum activity against various solid tumor types because these two integrin family members are clinically validated as being selectively expressed or overexpressed in a wide variety of solid tumor indications (and most mouse models). More information on the role of these integrins in cancer and the rationale for targeting them with VAX014 can be found here.
Preclinical studies conducted in multiple solid tumor models have produced promising results in immune competent mice. Studies in multiple models generally regarded as immunologically cold (few tumor infiltrating immune cells) and difficult to treat with immunotherapy have demonstrated that VAX014 results in local inflammation and immune infiltration into tumors following local administration. Inflammation and infiltration of tumors with immune cells culminates in T cell-dependent immune-mediated tumor clearance. Studies show tumor clearance(s) is durable, tumor specific, and leads to lasting protective systemic antitumor immunologic memory. In experimental models where mice bearing multiple tumors are treated locally by intratumoral injection of a designated tumor with VAX014, immune-mediated clearance of both treated and untreated tumors is observed (abscopal effect), indicating VAX014 facilitates in situ immunization against the treated tumor type. When combined with systemic immune checkpoint blockade therapy, protective systemic antitumor effects improve to a point where nearly all study subjects demonstrate complete response.
Vaxiion has two wholly-owned clinical stage oncology programs centered around VAX014 - one in bladder cancer and another in patients with advanced solid tumors.
VAX014 for Intralesional Injection
The company has received clearance of a second IND for the intralesional treatment of advanced solid tumors and will soon initiate a Phase 1 trial in patients with injectable solid tumors refractory to standard treatment options.