A Phase IIb, randomized, multicenter study of the efficacy of GVAX pancreas vaccine and CRS-207 compared to chemotherapy or to CRS-207 alone in adults with previously-treated metastatic pancreatic adenocarcinoma (eclipse study)

A heterologous prime-boost vaccination strategy using GVAX pancreas vaccine and CRS-207 is showing promise in patients with metastatic pancreatic adenocarcinoma (PDA). GVAX is composed of lethally-irradiated, allogeneic pancreatic cancer cells modified to express GM-CSF and induces a broad response against multiple tumor antigens. GVAX is given with low-dose cyclophosphamide (CY) to inhibit regulatory T cells. CRS-207 is live-attenuated Listeria monocytogenes engineered to express the tumor-associated antigen mesothelin. CRS-207 boosts responses against mesothelin and is unique in its capacity to stimulate both innate and adaptive immunity by activating T cells and NK cells. In a recently completed Phase II study, the CY/GVAX plus CRS-207 combination resulted in statistically-significant improvement of overall survival (OS) compared to CY/GVAX alone (Le, GI ASCO 2014)