Immunomodulation Program

PSI is developing a suite of polymers for delivering antigenic proteins that result in enhanced immune response for prophylactic and therapeutic vaccines. The program began with PCPP, a polyelectrolyte that is an alginic acid mimic and has shown strong potential as an immunomodulator for vaccines. PCPP has been manufactured under cGMP conditions and cGMP quality material is available. A Drug Master File (DMF) is on file with the FDA and is available for cross-referencing by appropriate partners.

As one immunomodulator may work for many, but not all, antigens, PSI designed and rapidly built a library of over 40 polyelectrolyte polymers around PCPP. This library was designed to display a range of physico-chemical characteristics that may make these polymers useful as delivery vehicles with a variety of diverse antigens. In addition, PSI has developed a series of in vitro methods to screen and pair PSI polymers with antigens of interest for vaccine development. After a "hit" has been identified through in vitro and in vivo screening, further refinement of promising immunomodulators can be accomplished by focused design and synthesis of additional related polymers to rapidly identify lead candidates.

The initial program is focused on antibody-based response critical to development of vaccines against many bacterial and viral illnesses. PSI is investigating the ability to extend the application of this technology to polymers capable of stimulating CTL or innate immunity by varying the side groups or additional constituents. PSI also has proprietary methods f or creating a range of formulations from hydrogels to microparticles, and is using these to investigate both injectable and mucosal delivery. Currently a number of library compounds including PCPP are under evaluation for potential licensing by a major vaccine manufacturer.