Intratumoral Vaccines

Numerous non-clinical and clinical studies have demonstrated the utility of intratumoral injections of strong immune stimulants in stimulating a therapeutic immune response to fight cancer. In this therapeutic vaccine, there is no external delivery of a specific tumor antigen. The mechanism is believed to rely on the endogenous release of tumor-derived antigens in the presence of the immune stimulant, creating a cytotoxic T cell response targeted to the tumor. When successful, an intratumoral vaccine induces a strong abscopal effect – a systemic immune response that not only eradicates the injected tumor, but also finds and destroys remote tumors and metastases.

Advantages of the Bullet Capsid in this application include very long residence time in the tumor (nearly all of the injected dose is still in the tumor 24 hours after injection), and combining novel combinations of immune stimulants and other molecules to create a strong tumor-specific cellular immune response.

Bullet Bio’s first proof-of-concept of this application was BB-006, a vaccine comprised of TLR-9 agonists attached to the outside of our Bullet Capsid core. BB-006 has demonstrated particularly promising results in combination with checkpoint inhibitors in preclinical studies. Bullet Bio continues to explore intratumoral vaccines and welcome partnerships in this area.