Use of Mouse Renal Adenocarcinoma Cell-containing Agarose-agarose Macrobeads in the Treatment of Patients With End-stage, Treatment-resistant Epithelial-derived Cancer

Cancer in its various forms continues to be a major U.S. health problem, accounting for 550,000 deaths a year, as well as much disability and suffering. Treatment for cancer has traditionally consisted of three modalities: surgery, radiation therapy, and chemotherapy. Advances with all three modalities over the years have produced long-term remissions and/or cures in certain types of cancer such as the leukemias, and prolonged survival for many other patients. Much remains to be accomplished, however, especially with respect to the treatment of solid tumors, including some of the most common cancers such as those of the lung, colon, breast, ovary, prostate and kidney. New types of less toxic and debilitating therapy are needed.

Among the therapeutic possibilities currently being explored, those that involve biological control mechanisms seem both promising and attractive. Although it has long been thought that cancer cells are not subject to the same regulatory growth control mechanisms that function in normal cells, there is a substantial body of evidence that they can respond to feedback signals telling them to slow or stop their growth. In addition, it has been determined that a relatively small population of cells within a tumor (cancer "stem" or progenitor cells) are responsible for continued tumor growth and that it is these cells that must be controlled if biological anti-tumor therapy is to be effective.

The proposed cancer treatment being tested in this Phase 1 clinical trial is based on the concept that tumor growth can be controlled by tumor mass or signals that indicate that such mass is present. In this case, however, the induction of the growth-slowing signals is brought about not by tumor mass, but by placing mouse kidney cancer cells in an agarose matrix, which both selects for cancer progenitor cells and also causes them to produce and release signals that inhibit the growth of freely growing cancer cells of the same or different type in a laboratory dish or in a tumor-bearing animal or human (i.e. is also not species-specific). This approach has proven both safe and effective in animal models and veterinary patients, and it is now in the first stage of human testing. With Phase 1 completed, we are now implementing Phase 2 efficacy trials that for the present are focused on colorectal cancer, pancreatic cancer, and prostate cancer. The Phase 1 trial remains open to a range of epithelial-derived cancer.