GVAX Pancreas

Vaccine: GVAX Pancreas
Company: BioSante Pharmaceuticals
Target: Pancreatic cancer

BioSante Pharmaceuticals' ($BPAX) GVAX Pancreas cancer vaccine is made from allogeneic (non-self) pancreatic cancer cells that have been genetically modified to produce the cytokine GM-CSF, which stimulates the immune system. The cells are also irradiated to stop them from growing. Pancreatic cancer is known as a "silent killer" because it is often symptomless, and has one of the worst outcomes of any cancer, with many patients only surviving three to 6 months.

In a study presented at the 2012 Gastrointestinal Cancers Symposium, the combination of GVAX Pancreas and Bristol-Myers Squibb's ($BMY) Yervoy (ipilimumab), a monoclonal antibody marketed for the treatment of melanoma, improved survival 60% in patients with pancreatic ductal adenocarcinoma, compared with ipilimumab alone.

Putting this into months, median survival increased from 3.3 months to 5.5 months in a group of seriously ill patients--patients with previously treated, advanced or metastatic disease. The number of patients still alive after one year almost quadrupled, from 7% to 27%, and the treated patients also showed an immune response against mesothelin, a biomarker seen in pancreatic ductal adenocarcinoma, the most common form of pancreatic cancer.

Because this was only a 30-patient Phase Ib study, it was designed to measure safety rather than efficacy, and the results can't really be used to compare the drugs directly. However, the outcomes were dramatic enough to trigger a rise in BioSante's shares of 14% earlier this year, and suggested to the research team that: "Immunotherapy has potential even in advanced pancreatic ductal carcinoma."

In Phase II results published in 2011, the GVAX Pancreas cancer vaccine, which has orphan drug designation from the  FDA, increased median survival more than 25% and one-year survival more than 35% in resected pancreatic cancer patients. These Phase I and Phase II results are a bit of a comeback for GVAX: In 2008, a Phase III clinical trial for the GVAX prostate cancer vaccine had to be closed after signs of a disconcerting trend in the number of deaths in the treatment arm of the study.