An experimental drug targeting a common mutation in melanoma successfully shrank tumors that spread to the brain in nine out of 10 patients in part of an international phase I clinical trial reported in the May 18 issue of The Lancet.
The drug dabrafenib, which targets the Val600 BRAF mutation that is active in half of melanoma cases, also cut the size of tumors in 25 of 36 patients with late-stage melanoma that had not spread to the brain. The drug also showed activity in other cancer types with the BRAF mutation.
"Nine out of 10 responses among patients with brain metastases is really exciting. No other systemic therapy has ever demonstrated this much activity against melanoma brain metastases," said study co-lead author Gerald Falchook, M.D., assistant professor in the Department of Investigational Cancer Therapeutics at The University of Texas MD Anderson Cancer Center.
Melanoma patients whose disease has spread to their brains have a median overall survival of four or five months from the time of diagnosis, the researchers note. Drugs used to treat brain metastases have response rates of 10 percent or lower. Surgery and stereotactic or whole-brain radiation also are used.
Tumor shrinkage in the nine responders ranged from 20 percent to 100 percent. In four cases, the brain metastases disappeared.