Our Approach

Apthera is developing immunotherapies to fight cancer. The immunotherapy of cancer aims at specifically activating cells of the immune system, especially the so-called cytotoxic T-cells ("killer T-cells") to seek out and eliminate tumor cells but not harm healthy tissue.

NeuVax  is active because it “turns on” the immune system.  NeuVax recruits the main components of the cellular immune system to fight cancer by presentation of a T-cell peptide epitope in the context of the peptide-HLA-T-cell receptor complex. When NeuVax is administered, the E75 peptide, a well established T-cell epitope discovered on HER2, binds to the HLA-A2 and HLA-A3 molecules on the surface of tumor cells and Antigen Presenting Cells (APCs). The peptide sends a signal to the immune system by binding in the HLA-peptide-T-cell receptor complex.  Circulating T-cells recognize the peptide bound to HLA though T-cell receptors (TCRs) on their surfaces and the T-cells become "educated" and "activated" to target HER2-expressing tumor cells exhibiting the E75 epitope bound to HLA. Furthermore, activation of these T-cells leads to clonal expansion and proliferation of E75-specific “killer T-cells” that circulate through the body, identify and destroy cancer cells that are processing HER2.

Tumor cells are differentiated from healthy cells by the expression of tumor-associated proteins, also known as “tumor antigens.” HER2/neu is a well established tumor-associated antigen found at various expression levels on the membrane  surface of many types of human cancer cells. The human immune system is constantly under surveillance for foreign invaders (foreign proteins) or abnormal self proteins. To aid in this immune surveillance, cellular proteins such as HER2/neu and others are routinely digested or broken down inside the cell into short fragments called peptides and the small peptides are then “displayed” on the cell surface as a means of communicating with the immune system. Differences between the pool of peptides from a tumor cell and a normal cell are revealed on the outside of the cell.  Peptides that are presented on or from tumor cells, but that are absent (or to a far lesser extent on healthy cells) are called tumor-associated peptides (TAPs).

Activation of T-cells by NeuVax (E75) Leads to Expansion of the Activated T-cell Clones and Immune-Mediated Tumor Lysis Priming of T-cells by MHC Presentation of Peptide Induces Activation and Proliferation