StemCell Therapy

By Robert Langreth - Thu Mar 08 05:00:01 GMT 2012

Radiating one tumor can trigger the immune system to wipe out tumors in other parts of the body and may boost the effectiveness of Bristol-Myers Squibb Co. (BMY)s cancer drug Yervoy, doctors have shown.

Researchers at Memorial Sloan-Kettering Cancer Center are reporting on the case of a 41-year-old woman with advanced melanoma who took Yervoy, a drug that stimulates the immune system to fight cancer cells, in a clinical trial. She didnt respond to the medicine until she got a radiation treatment to shrink a tumor on her lung that was pressing on a nerve and causing severe back pain.

Soon, all the other tumors in her body started shrinking, according to the results published in the New England Journal of Medicine. The case is the best demonstration to date of a rare phenomenon called the abscopal effect, in which radiation to just one tumor causes other tumors all over the body to regress, said Charles Drake, a medical oncologist at the Johns Hopkins University School of Medicine not involved with the study.

It is a really amazing finding, Drake said in a phone interview. It confirms that this effect can occur.

The broad tumor shrinkage was associated with changes in the immune system that occurred after the radiation treatment, according to the report.

Harnessing the effect may enable researchers to boost the response rate to Yervoy, said Memorial Sloan-Ketterings Jedd Wolchok, an oncologist and senior author on the case study. The radiation-linked response may occur because the radiation creates cellular debris that the immune system recognizes as dangerous, he said.

Yervoy for melanoma is the first in a new class of drugs that removes molecular brakes on immune system cells that prevent them from attacking cancer. While it improves survival by four months, the drug causes major tumor shrinkage in 10 to 15 percent of melanoma patients. Doctors are looking for a way to improve on this.

Valerie Esposito, the radiation patient in the study, started getting Yervoy in September 2009 and didnt clearly benefit at first. She was definitely getting worse until she got the radiation in December 2010, said Wolchok.

Yet when doctors performed a scan a few months after the radiation, six tumors in her spleen and two more in her lymph nodes that had not been radiated shrank dramatically, he said.

Continued here:
Radiation Blast May Turbocharge Bristol-Myers Melanoma Drug, Report Shows

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