Melanoma drug showing promise: ; Experimental medication made tumors shrink in nearly half of patients

An experimental drug designed to attack a tumor's genetic triggerhas produced dramatic results in patients with advanced melanoma,one of the deadliest and most impervious cancers, researchersreported Sunday.

The drug - known so far only by its technical names vemurafeniband PLX4032 - made tumors shrink significantly in nearly half ofpatients studied, reduced the risk the disease would progress bynearly two-thirds and slashed the chances of dying by 63 percent.

The eagerly awaited results provide some of the clearest evidenceyet that drugs created to pinpoint molecular characteristics ofpatients' cancers can produce unprecedented benefits.

"This is really a huge step toward personalized care inmelanoma," said Paul Chapman of the Memorial Sloan-Kettering CancerCenter in New York, who led the study. "This is the first successfulmelanoma treatment tailored to patients who carry a specific genemutation in their tumor."

Chapman and others cautioned that the drug is not a cure and manypatients' tumors appear to become resistant to the treatment, makingit unclear how long it may prolong their lives. But for a diseasethat has been so difficult to treat, the results are striking.

"This is really unprecedented for patients with melanoma," saidLynn Schuchter of the University of Pennsylvania, who moderated thepanel where the results were presented at the annual meeting of theAmerican Society of Clinical Oncology in Chicago. "It just changesthe landscape for patients."

Conventional chemotherapy usually works by killing any rapidlydividing cells. Because cancer cells proliferate quickly, chemodrugs can shrink tumors. But they also kill healthy cells, which iswhy they cause nausea, vomiting, hair loss and other oftendebilitating side effects.

PLX4032 is one of a new generation of drugs that researchers hopewill be more effective and less toxic because they zero in ongenetic characteristics of cancer cells that are not found inhealthy cells.

"Whereas in the past we had to use a shotgun approach to cancertreatment - treating many to help a few - we now are on the cusp ofa new era in cancer treatment where we can use these predictivetests to focus our treatments on those patients who are most likelyto respond to a specific cancer treatment," said J. LeonardLichtenfeld, deputy chief medical officer at the American CancerSociety .

Melanoma strikes more than 68,000 Americans each year and killsabout 8,700. Despite decades of research, it remains one ofdeadliest malignancies with few treatment options.

"This is a very exciting and important study in a disease thatfor decades has resisted any meaningful treatment when it has spreadthrough the body," Lichtenfeld said.

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