Aduro BioTech, Inc. announces the treatment of the first patient in the Phase 2 pancreatic cancer clinical trial of the sequential administration of two cancer vaccines: Aduro's CRS-207 and GVAX Pancreas Cancer Vaccine (GVAX Pancreas). The randomized, controlled clinical trial will enroll a total of 90 patients to evaluate the overall survival as well as the safety and immune response.
CRS-207 is based on Aduro's platform of attenuated Listeria monocytogenes (Listeria) strains that have been genetically modified for safety, while maintaining their ability to stimulate a potent immune response. CRS-207 has been engineered to induce cytotoxic T cells specific for the tumor-associated antigen mesothelin. The therapeutic cancer vaccine was evaluated in a Phase 1 trial in 17 end-stage patients with cancers known to express mesothelin: mesothelioma, non-small-cell lung, ovarian and pancreatic. Despite a historical average survival time of only 3-5 months for this end-stage patient population, six out of 17 patients treated with CRS-207 in this Phase I trial lived 15 months or longer.
GVAX Pancreas was licensed from BioSante Pharmaceuticals, Inc. (NASDAQ:BPAX) for use in combination with Aduro vaccines. GVAX vaccines are composed of allogeneic (not patient-specific) cancer cell lines that have been genetically-modified to secrete granulocyte-macrophage colony-stimulating factor (GM-CSF) to stimulate the immune system and that have been treated to prevent cell division. GVAX Pancreas is administered with low-dose cyclophosphamide, which has been shown to increase effectiveness.
Sequential administration of GVAX Pancreas followed by CRS-207 was first shown by Aduro to be synergistic in mouse models, demonstrating enhanced tumor-specific T cell immune responses. Because both GVAX Pancreas and CRS-207 target the tumor-associated antigen mesothelin, the sequential administration is a heterologous prime-boost regimen. Aduro's Listeria-based vaccines are known to be especially effective in this regimen.
Based on the synergy in preclinical animal models, three pancreatic cancer patients who had been treated with GVAX Pancreas as part of separate clinical trials were included in the CRS-207 Phase 1 clinical trial. All three of these end-stage patients survived 15 months or longer.
"To meet the challenge of developing effective treatments for pancreatic cancer," said Stephen Isaacs, Chairman and Chief Executive Officer of Aduro BioTech, "we are bringing together two promising therapeutic cancer vaccines and collaborating with leading physicians at top-tier medical centers."