Genetic instability is a hallmark of cancer and, consequently, each cancer patient’s tumor genome (i.e., the DNA of the tumor cell) is different from their normal cells. This DNA difference leads to the creation of new protein antigens that are specific to tumor cells. These new antigens, known as tumor-specific neo-antigens (TSNAs), can be recognized and targeted by the immune system.
Gritstone Oncology is exploiting this inherent vulnerability of tumor cells by identifying a patient’s unique set of tumor antigens and using them in a therapeutic immunization strategy. Critically, every cancer patient’s tumor genome is unique. Gritstone accepts this complexity, and rather than pursuing antigens “shared” between patients (the historic approach), will develop truly patient-specific, synthetic neo-antigens.
The company’s approach will involve three key steps: 1) Evaluating each patient’s tumor using real-time next-generation sequencing and custom bioinformatics to identify and catalog the individual TSNAs, 2) Using proprietary algorithms to identify the lead candidate TSNAs predicted to activate tumor-specific T cells, 3) Delivering personalized synthetic TSNAs in a vaccine base to patients (vaccine alone or in combination with immune checkpoint blockade).