Therapeutic Cancer Vaccines
Therapeutic vaccines are based on the premise that cancer develops as a result of the immune system not mounting an effective immune response against cancer cells, and that the immune system can be "trained" to recognize and attack cancer cells, halting the growth of established tumors. Therapeutic vaccines are used much differently than traditional preventative vaccines, as they are administered to treat existing disease rather than to prevent disease.
Cancer cells display antigens (substances that can trigger an immune response) that can be targeted by the immune system. A therapeutic vaccine that targets these tumor-associated antigens has the potential to stimulate the immune system to attack cancer cells, without destroying healthy cells, eliciting tumor-specific immune responses and inducing long-term remission.
Despite the significant promise of therapeutic vaccines for cancer treatment, their development has met important challenges. Among these challenges is the difficulty in distinguishing cancer cells from normal cells, as cancer cells carry normal self-antigens alongside tumor-associated antigens. Another challenge involves tumor-induced immune suppression or immune-evasion mechanisms, whereby cancer cells produce chemical messages that suppress immune responses and undergo genetic mutations that evade the immune system. Additionally, therapeutic cancer vaccines are typically used in patients with later-stage disease, when the immune system is already compromised and less able to mount a response.
OncoPep's lead therapeutic cancer vaccine, PVX-410, has the potential to overcome many of the obstacles that have encumbered cancer vaccines in the past.