Imprime PGG - Mechanism of Action
Imprime engages a novel mechanism of action to treat cancer. It binds to neutrophils, a type of innate immune cell that is the most abundant immune cell in the body. Neutrophils represent 50% to 70% of all white blood cells, a cellular population that is 10 to 15 times larger than any other group of immune cells.
These innate immune cells are exceedingly effective killers of pathogens (bacteria, virus and fungus) whose cell surfaces contain molecules that enable the immune system to easily recognize them as not human. This recognition of “non-self” is the critical characteristic required for innate immune cell killing. These innate immune cells, however, are not normally involved with anti-tumor activity because cancer cells are “self” cells. As a result, this very large army of innate immune cells is generally thought to be ineffective against cancer cells.
Imprime binds to a specific receptor on the surface of neutrophils and can enhance multiple immune cell functions. When the immune system identifies a pathogenic challenge in the body, it creates an inflammatory condition at the site of the challenge to attract immune cells to deal with it. When Imprime binds to neutrophils, one enhanced function is that they migrate or chemotax to an inflammatory site more efficiently. Biothera has also discovered that if the inflammation is a tumor site, Imprime bound neutrophils will engage in anti-tumor activity, a function not normally activated against cancer cells. The idea of mobilizing the largest population of immune cells to engage in anti-tumor activity is a novel therapeutic approach.
Imprime can be an effective cancer therapy when combined with a targeting drug that will create the inflammatory condition at the tumor site. One of the body’s natural immune mechanisms to create inflammation at a pathogenic challenge site is the process of making antibodies that will bind to the pathogen. In the last 15 years, pharmaceutical companies have developed several monoclonal antibody (MAb) drugs that mimic these natural antibodies and target human cancer cells. These MAbs bind to tumor-associated antigens or markers found on the surface of cancer cells. When bound, they can create the necessary inflammation resulting in immune cell migration to the tumor. Research data demonstrates that when Imprime is administered in combination with MAbs, there is a anti-tumor effect that is significantly better than the MAb alone.
Imprime’s novel cancer killing mechanism mimics the natural mechanism that neutrophils use to kill pathogens and is additive to the mechanisms induced by anti-tumor MAbs.
Clinical and preclinical studies demonstrate the success of Imprime PGG against a wide range of cancers. As such, it is a platform technology that with numerous potential applications.