patients who were treated with PLX4032 had already received multiple treatments of other cancer drugs , all of which had failed . Two-thirds of those patients also already had what Eggermont described as `` very widespread metastatic disease . '' `` There were patients who were on oxygen or on continuous morphine who were off the morphine after one or two weeks of treatment , '' Eggermont told CNN . Two patients , he said , even showed complete remission , such that all detectable melanoma `` melted away . '' The other two major benefits of PLX4032 are that it can be taken orally as a pill and seems to have very mild side effects . The PLX4032 complex works by blocking the activity of cancer-causing mutation of the BRAF gene , which is implicated in more than half of all melanomas . Eggermont praised the drug for being highly-selective unlike traditional `` dirty '' cancer drugs that have a wide range of side-effects . `` The side effect profile looks very mild and we think it 's because it 's such a clean , super selective molecule and it 's an oral drug , and that 's a
LONDON , England -- A new drug for melanoma has been shown to rapidly shrink malignant tumors in an early trial at Memorial Sloan-Kettering Hospital in New York . New drug inhibits BRAF , the main driver of mutation in over 50 percent of melanomas . Among 27 patients whom the experimental new drug was tested on , `` 19 showed a 30 percent or greater reduction in tumor size , '' Dr. Paul Chapman , the lead researcher told CNN from a cancer conference in Berlin . Melanoma develops in cells that produce melanin , the pigment that gives skin its color , and is the most serious type of skin cancer . Currently the standard treatment for metastatic malignant melanoma is chemotherapy , which has only a 15 percent success rate , Chapman explained . In his trial using PLX4032 over 70 percent of patients had a response to the drug . `` Without reservation we can say this is a breakthrough in melanoma . We have n't seen a major breakthrough in this disease in the last 40 years , '' said Professor Alexander Eggermont , President of the European Cancer Organization . Seventy-five percent of the