Certainly melanoma can be a very serious and sometimes deadly type of skin cancer. However, there is a new drug that extends progression-free survival in patients dying of advanced melanoma.
The majority of patients with advanced, metastatic melanoma gain only a few months extra survival from standard treatment. But early tests show that an experimental drug, named PLX4032 by Plexxikon and Roche Pharmaceuticals, offers far greater benefits. The findings are particularly amazing as they come from a very early, phase I clinical trial. Study leader Keith T. Flaherty, MD, is director of developmental therapeutics at Massachusetts General Hospital. According to Dr. Flaherty, “For those who respond to treatment, the average duration of progression-free survival is nine months.” “Some patients are over a year and a half and cruising to two years. In melanoma, that is good. The average time for standard treatment is two months.”
There is a catch. The drug targets a specific genetic mutation that helps melanoma tumor cells grow. About 40% to 60% of melanoma patients have tumors with this mutation. For those who don’t, the drug offers no help and possible harm. Fortunately, a simple genetic test identifies patients likely to respond to the drug.
Details of the study:
1) In its initial phase, the study enrolled 55 patients, 49 with metastatic melanoma.
2) An additional 32 patients with metastatic melanoma enrolled in the study’s extension phase.
3) All patients carried the BRAF mutation targeted by the new drug.
4) 81% of patients with BRAF-positive melanoma responded to treatment.
5) Duration of response ranged from two to over 18 months.
6) Three of the melanoma patients no longer had detectable tumor in their bodies. (Dr. Flaherty says such “complete responses” are not the same as cures).
Like other medications, this drug (a pill taken twice daily) does have side effects. The most common ones are a rash, sun sensitivity, joint discomfort, and fatigue. A number of patients also developed non-deadly squamous-cell carcinomas on the skin. These side effects tend to be moderate and manageable.
The drug’s most important drawback is that it isn’t a cure. Eventually, tumor cells find new ways to grow and become resistant to the new drug.
