[ot] Therapies for Cancer Bring Hope and Failure

June 15, 2010

BlankJune 14, 2010

Therapies for Cancer Bring Hope and Failure

By ANDREW POLLACK

CHICAGO — The experimental drug PLX4032, which reverses the effects of a

mutation found in certain tumors, is considered a prime example of the

“targeted” cancer therapies of the future. The drug — the subject of a

three-part series in The New York Times in February — produced seemingly

miraculous results in some patients with melanoma.

But when the same drug was tried in patients whose colorectal tumors had the

same mutation, there was barely any effect, researchers reported here last week

at the annual meeting of the American Society of Clinical Oncology.

Same drug, same mutation, different result.

The findings serve as another reminder of how devilishly complex cancer can be

and how much more remains to be understood. They provide a sobering check on the

enthusiasm that had been building about the targeted therapies, which act to

block particular abnormalities that spur tumor growth.

“This is one of the few warning shots over the bow,” said Dr. Kopetz of

the M.D. Cancer Center in Houston, who led the colorectal cancer study.

Indeed, even as researchers at the meeting hailed the latest drug successes,

they acknowledged that the path forward was not as easy as once envisioned. Many

targeted therapies are failing in clinical trials.

“We’ve gone through a very rapid period of high expectations, maturation and

disappointments,” said Dr. J. Leonard Lichtenfeld, the deputy chief medical

officer of the American Cancer Society. “I think there was almost a naïveté that

if we could find the target, we would have the cure.”

Dr. Kopetz said that after a period of huge gains that culminated with the

approval in 2004 of two targeted drugs, Avastin and Erbitux, progress against

colon cancer had stalled. “In the past five years I don’t think we’ve made any

headway,” he said.

Full story

ma5 & pagewanted=print

Recommended Posts