Antibody’s actions may attack tumors’ blood supply

An antibody known as J591 may precisely target the blood supply of various urologic and other tumors while avoiding healthy tissues, according to research from New York-Presbyterian Hospital/Weill Cornell Medical Center, New York.

In the phase I clinical trial, results of which are published in the Journal of Clinical Oncology (2007; 25:540-7), researchers ran tests on the J591 antibody, which was targeted at the prostate specific membrane antigen (PSMA). Researchers say PSMA is an attractive target for cancer drug development because it is not only present in high amounts in prostate cancers but it also is the only known molecular target present on tumor blood vessels but not normal blood vessels.

During the trial, a radioactive tracer was connected to the antibody to monitor J591’s activity in the body. Investigators evaluated 27 cancer patients, who presented with various solid tumors, including those of the kidney, bladder, lung, and pancreas. All patients had some form of disease that failed traditional therapy.

“We showed that J591 can directly target the tumor’s blood vessels,” said the study’s senior author, Neil H. Bander, MD. “Current anti-angiogenic approaches starve the blood vessels of growth signals, but with J591, one directly targets a lethal blow right at the tumor blood supply.”

The actions of the antibody may prove beneficial in development of future anti-angiogenic therapies.

Dr. Bander is a consultant to, and owns stock in, BZL Biologics, which has licensed the PSMA antibodies from Cornell.