Application of our Hierotope® Platform
The first product candidates that we have generated using our Hierotope platform are antibodies to infectious agents, such as VIS410 for influenza A and VIS513 for Dengue. We are now also applying our platform to design and engineer high-affinity antibodies to endogenous targets. Our antibody-based biological product candidates and early-stage programs fall into three categories:

1. Monoclonal Antibodies: In the case of infectious diseases, our monoclonal antibody product candidates are designed and engineered to bind to the Hierotope, neutralize the pathogen and recruit immunological cells to enhance the activity of the product candidate. VIS410 and VIS513 are our most advanced monoclonal antibody product candidates for infectious diseases, and we are developing several others as part of our early-stage programs. For endogenous targets, our monoclonal antibody product candidates are designed and engineered to bind to the Hierotope and selectively inhibit the biological activity of the target. VIS649 is our most advanced monoclonal antibody product candidate that targets an endogenous protein.
2. Bispecific Monoclonal Antibodies: For diseases where a therapeutic effect requires binding to two targets, we design and engineer a bispecific monoclonal antibody that binds to both Hierotopes and selectively inhibits the biological activity of the targets. In our early-stage programs for the treatment of respiratory syncytial virus, or RSV, and for the treatment of severe fungal infections, we are developing bispecific monoclonal antibody product candidates.
3. Antibody-Drug Conjugates, or ADCs: These product candidates are designed and engineered to enhance the killing of infectious organisms by dual mechanisms. ADCs have a monoclonal antibody component and a drug component. The monoclonal antibody attaches to the organism and facilitates the recruitment of the host immune cells which then engulf and kill the organism. The drug component is a bactericidal peptide that directly kills the organism. The resulting ADC delivers the toxic peptide to the target organism and effects direct killing. We are developing our ADC product candidate, VIS705, as a single-dose curative therapy, engineered to kill all strains of the deadly Pseudomonas bacteria, including strains that have been found to be multi-drug resistant
We have also expanded the application of our Hierotope platform to modify other important properties of antibodies, beyond affinity and specificity to the given target. Specifically, the fragment crystallizable, or Fc, region of an antibody is responsible for controlling several properties of an antibody, including the ability to recruit immune proteins and cells. We have deployed our Hierotope platform to identify alterations within the Fc region to engineer antibodies with desirable properties, including extended half-life, and enhanced ability to recruit immune cells. These capabilities, which we call ViStar™ antibody Fc engineering, support the development of long-acting monoclonal antibodies for the extended protection in infectious diseases and less frequent administration in chronic diseases.

As of 09/15/17
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