
                         Roanoke Times
                 Copyright (c) 1995, Landmark Communications, Inc.

DATE: FRIDAY, July 9, 1993                   TAG: 9307090080
SECTION: NATIONAL/INTERNATIONAL                    PAGE: A-3   EDITION: METRO 
SOURCE: The New York Times
DATELINE:                                 LENGTH: Medium

BIOLOGICAL BULLET FIGHTS CANCER

After years of hopes raised but dashed that a magic bullet against cancer could be invented, scientists have reported an impressive advance in using a sort of molecular sharpshooter to destroy tumor cells.

In the new research, scientists have designed so-called monoclonal antibodies that seem considerably more effective in wiping out cancer than antibody proteins in previous attempts. The results have been seen only in rodents, and even if the new approach proves valid, much work must be done before the technique can be used on patients.

Nevertheless, scientists familiar with the history of attempts to design proteins that specifically attack cancer cells said the findings were extremely encouraging.

They were most impressed with the ability of the therapy to cure cancer in rodents that had well-established and widespread malignancy. In most previous animal studies of monoclonal antibodies, researchers had managed to cure or diminish only confined tumors that had barely begun to grow.

Dr. Lance Liotta of the National Cancer Institute in Bethesda, Md., an expert in how cancer spreads throughout the body, said the "apparent ability to achieve cures in the face of disseminated disease is very exciting."

The findings, from three research institutes of Bristol-Myers Squibb Pharmaceutical Co., appear today in the journal Science.

The researchers hooked up a commonly used chemotherapy drug called doxorubicin to an antibody able to home in on a specific molecular target, or antigen, that is found in abundance on the surface of tumor cells.

Once the antibody had found its objective, it was effectively sucked inside the cancer cells, where its poisonous drug was freed to kill the cells by jamming up the chromosomes within.

The technique cured extensive cancers in 70 percent of mice in which human tumors of the breast, lung and colon had been implanted and allowed to grow from two weeks to 26 days.

By comparison, rodents left untreated, given doxorubicin alone, or injected with antibodies that did not bear a chemotherapeutic cargo, quickly died from their tumors.

In most previous animal experiments that have seen supposedly miraculous cures of cancer, researchers have applied their treatment within several days of implanting the creatures with tumor cells.

by CNB