Sequence matters when using n...( TORONTO - An experimental agent that ta...)

The finding is important because the new therapy, known as PS-341 (Velcade), will likely be tried as new treatment for a number of cancers due to its effectiveness in multiple myeloma, says Christos Papandreou, M.D., Ph.D., assistant professor in the department of Genitourinary Medical Oncology.

"It appears PS-341 could become quite a hit as a novel proteasome inhibitor, a drug that increases the effectiveness of chemotherapy agents," Papandreou says. "We know that while the sequence it is used in doesn't matter with certain classes of chemotherapy drugs, it does with others. Hopefully, future clinical trials will reflect this new understanding."

The findings were published in the Proceedings for the 2003 Annual Meeting of the American Association for Cancer Research.

Last summer, the agent demonstrated a dramatic success when used to treat patients with multiple myeloma. Researchers at Dana-Farber Cancer Institute, where it was tested, said 70 percent of 78 patients with advanced multiple myeloma improved - an unheard of benefit in that disease. The agent is now being used in a Phase II clinical trial in advanced prostate cancer, and several Phase I clinical trials are underway, or have been completed, testing PS-341 in pancreatic, lung and colorectal cancers.

The drug is designed to specifically inhibit proteasomes, the cell's enzymatic protein-shredding machinery, responsible for breaking down a variety of proteins, including many that regulate cell division.

M. D. Anderson researchers designed experiments in which they treated prostate cancer cells with PS-341 alone or in combination with
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Contact: Laura Sussman
lsussman@mdanderson.org
713-792-0655
University of Texas M. D. Anderson Cancer Center
9-Apr-2003