New Drug Could Slow Spread of Prostate Cancer

Scientists report they have developed a drug that can prevent prostate cancer from spreading to nearby tissues and bone, increasing the chances of successful treatment.

The experimental compound doesn't cure prostate cancer. It contains the disease so more traditional cancer therapies, such as surgery and radiation, have a chance to work.

Raymond Bergan is director of experimental therapeutics at the Robert H. Lurie Comprehensive Cancer Center at Northwestern University in Illinois, where the drug was developed.

Using breast cancer as an analogy, Bergan says it's not the original cancer that's lethal, but its spread or metastasis.

"The relevance of that is life versus death, literally," he says. "If the cancer is localized, it's very treatable, curable. If the cancer has spread throughout the body, it will take her life. We can treat it, but it will take her life."

The new drug, called KBU2046, is a small molecule that attaches to tumor proteins involved in metastasis and disables them, so they can't travel to distant organs. Bergan says it's like turning off a switch that tells the cells to keep moving all the time.

Bergan and his colleagues transplanted aggressive human prostate cancer cells into mice, and then fed them the drug for five weeks. The compound prevented metastasis of the cancer to the lungs, a frequent site of tumor spread in men with prostate cancer.

Toxicity studies showed the compound is safe. Unlike other cancer therapies, which can cause significant side effects, investigators say the experimental drug spares healthy cells, causing minimal side effects.

Bergan is confident that KBU2046 will work to contain other cancers as well.

"We don't think it's specific to prostate cancer. We've done some early tests with other cancer cells in the laboratory and it appears to stop them from moving."

Bergan stresses that drugs developed using animal models don't always work in humans, and he's looking forward to trials involving cancer patients.