Advanced prostate cancer patients who have become resistant to standard hormone treatment therapy may be eligible to participate in a UCSF/Mount Zion Cancer Center clinical trial of a drug that researchers hope will inhibit the growth of blood vessels that nourish tumor cells.
The drug, developed by Genentech Inc., is a protein known as an antibody that inhibits a growth factor called VEGF, or vascular endothelial cell growth factor.
Many cells produce VEGF to help stimulate the growth and migration of blood vessels into the cellular environment in a beneficial way, as for supplying nutrients during wound healing. But many types of cancer cells also produce VEGF, and they produce higher than normal levels.
The UCSF/Mount Zion trial will attempt to ascertain whether the antibody to VEGF, called rhuMAb VEGF, will successfully block the development of blood vessels by prostate tumor cells. In laboratory studies, the antibody did inhibit the growth of human prostate cancer cells grown in animals.
"Considerable laboratory evidence suggests this drug works," said Eric Small, MD, UCSF associate clinical professor of medicine and urology and co-director of the Urologic Oncology Program at UCSF/Mount Zion Cancer Center. "We hope that anti-VEGF antibody will disrupt blood vessels and help slow or stop the growth of prostate cancer."
The anti-VEGF antibody is not the same drug as the compounds angiostatin and endostatin developed in Boston and the subject of recent news stories, although it appears to work by a similar mechanism. Anti-VEGF, like the other drugs, is intended to block the growth of blood vessels in and around tumor cells, thereby stopping the growth of the tumors themselves.
The new UCSF/Mount Zion study will be a phase II clinical trial, the stage of new drug testing designed to determine a drug's effectiveness.
To qualify for the anti-VEGF antibody trial at UCSF/Mount Zion, patients must have metastatic prostate cancer, no longer be responsive to hormone therapy, have had no prior chemotherapy and have climbing PSA (prostate-specific antigen) blood tests.
Patients interested in participating should contact UCSF/Mount Zion Cancer Center trial coordinator Steve Charfauros at (415)885-7329. Patients who are not eligible for the anti-VEGF trial but who would like to learn about other investigational treatment options for prostate cancer should contact Pam Schneider, RN, in Small's office at the UCSF/Mount Zion Urologic Oncology practice at (415) 885-7331.
UCSF/Mount Zion is part of UCSF Stanford Health Care.
The anti-VEGF antibody is administered through the vein, on an outpatient basis, over 60 minutes once every two weeks. Study participants will receive at least six treatments.
A phase I clinical trial determined that the drug is safe to use, with minimal side effects, though long-term effects are not known. The ten patients already enrolled in the phase II study have, to date, experienced no side effects.