Cancer drug Avastin shrinks ear-nerve tumors

Avastin, a widely used cancer drug, shrank tumors growing along the nerves leading to the ears, improving the hearing of patients with a rare tumor, researchers reported on Wednesday.

The findings suggest that Avastin, already used to restrict the flow of blood to advanced colon and lung tumors, can help people with neurofibromatosis type 2, an inherited benign type of tumor that strikes 1 person in 25,000, attacks the nervous system, and typically leaves victims deaf by middle age.

“It’s an important step because there’s never been a medical treatment that’s been shown to be effective in these benign tumors,” Dr. Scott Plotkin of the Massachusetts General Hospital Cancer Center, who led the study, said in a telephone interview.

The current treatment for the slow-growing tumors, which primarily affect hearing and balance, is surgery or radiation, which themselves can harm hearing.

The drug, known generically as bevacizumab, shrank the tumors in nine out of 10 volunteers, according to the results published online by the New England Journal of Medicine.

Before treatment, the tumors had been growing by 62 percent per year.

Out of seven patients who were losing their hearing before treatment, four got some of it back, sometimes in less than 12 weeks, “and they improved for as long as we studied them,” Plotkin said.

The treatment was no cure. Tumors shrank 20 percent or more in only six of the 10 patients and the effect was only temporary in two.

But even in a 16-year-old patient whose tumor did not shrink significantly, the treatment relieved his headaches and nausea, probably caused by the growth pressing on the base of the brain.

Doctors in other hospitals are testing the treatment, Plotkin said.

Genentech, now a unit of Roche, developed the drug. Neither company financed the study.

On Tuesday, Plotkin and his colleagues enrolled their first patient in a follow-up study designed to try a different drug—PTC299 from the privately held PTC Therapeutics Inc. in South Plainfield, New Jersey.

The experimental drug also inhibits the growth of blood vessels feeding tumors but can be given by mouth.

Plotkin said the study published in the New England Journal defied the conventional wisdom that benign tumors do not respond to chemotherapy, that they do not spark the growth of nourishing blood vessels and that hearing cannot be restored once these tumors have taken it away.

“On a number of levels, this represents an interesting turn of events,” he said.

SOURCE: New England Journal of Medicine, online first July 8, 2009.