In an interesting step with intriguingly complex promise, the Office of Orphan Products Development of the U.S. Food and Drug Administration recently designated the immunotherapy CRS-207 as having orphan drug status for use in sequential combination with the GVAX Pancreas biologic for the treatment of pancreatic cancer. Both of these immunotherapeutic agents are owned by Aduro BioTech Inc. of Berkeley, California.
This move by the FDA coincides with Aduro having recently completed a randomized controlled Phase II clinical trial of patients with metastatic pancreatic cancer with this regimen (as yet unpublished), and appears to have sprung from the earlier work of Laheru and colleagues at Johns Hopkins University pursuant to a study published in the February 2012 issue of Clinical Cancer Research, the official journal of the American Association For Cancer Research. In this earlier Phase I research study, three of the patients with pancreatic cancer who had been earlier treated with GVAX appeared to show disease stability after the addition of further immunotherapy that included CRS-207.
Although vaccines and immunotherapies have been an interesting concept in theory generally in cancer and specifically in pancreatic cancer – there have been no clear breakthroughs.
CRS-207 is a live but attenuated Listeria monocytogenes strain that is aimed to induce an immunologic response specific to the antigen: mesothelin – which tends to be over-expressed in pancreatic adenocarcinoma. GVAX is a biologic that stimulates “granulocyte-macrophage colony-stimulating factor” (GM-CSF), boosting white cells including monocytes that roam and can mature into macrophages and dendritic cells – which augment the immune system’s ability to fight cancer.
In February 2013, Aduro purchased GVAX from BioSante Pharmaceuticals, Inc. Drew Pardoll, MD, PhD of Johns Hopkins University is the Chairman of the Scientific Advisory Board of Aduro BioTech. He and other researchers from Johns Hopkins have been involved in research with GVAX and pancreatic cancer for over a decade.
This 1-2 punch (CRS-207 / GVAX) at different areas of the immunologic / inflammatory cascade is a clever and promising idea. It will be interesting to see the results of the Phase II work, and to follow the results of this novel and creative line of study.
Dale O’Brien, MD