November 21, 2003

BY JIM RITTER Staff Reporter

An experimental drug is proving surprisingly effective in treating patients with advanced kidney cancer who have no other hope.

In a small study at the University of Chicago and four other centers, the drug shrank tumors by at least one-fourth in 42 percent of patients and by more than half in 12 percent. The drug's developers are evaluating whether it also might work for other cancers, including melanoma, liver and pancreatic.

The drug, BAY 43-9006, is the most promising development in kidney cancer in at least 10 years, said U. of C. kidney cancer specialist Dr. Walter Stadler.

However, researchers cautioned BAY 43-9006 isn't a cure. In all 50 patients studied, the drug failed to completely eradicate tumors.

The results, announced Thursday at the American Association of Cancer Research meeting in Boston, are preliminary. Bayer Pharmaceuticals and Onyx Pharmaceuticals, which paid for the study, are planning a follow-up study of 800 patients. It is not approved for use outside of studies.

The drug might prolong the lives of patients whose kidney cancer has spread. Today, the median survival time is eight to 12 months.

Each year in the United States, about 32,000 people are diagnosed with kidney cancer, and 12,000 people die. The main treatment is removing the kidney. If tumors spread, chemotherapy usually doesn't work.

BAY 43-9006 originally was developed for colon cancer. Researchers included patients with other cancers on the chance they would be helped. The drug proved ineffective against colon cancer but worked surprisingly well against kidney cancer.

Researchers speculate BAY 43-9006 blocks an enzyme that regulates the proliferation of cancer cells. Or perhaps it chokes the blood supply to tumors. Maybe it does both.

Compared to many cancer drugs, BAY 43-9006 has mild short-term side effects, including rash, diarrhea and high blood pressure. It's unknown whether there will be long-term side effects.

U. of C. kidney cancer patient Donald Jeffers said he was surprised at how easy the drug was to take. "Two pills in the morning, two pills at night," he said. "It's like taking M&Ms."

Jeffers, 69, had a cancerous kidney removed in 1981, but 14 years later he discovered the cancer had spread. He now has one tumor in his lung and two in his chest. BAY 43-9006 has shrunken his lung tumor by 50 percent and stopped the other two from growing.

Jeffers said he doesn't expect to be cured. But he added, "I'm still here."