An experimental personalized cancer therapy from Roche and Plexxikon registered striking results in a recent clinical study, shrinking the tumors in a majority of metastatic melanoma patients who share a common genetic mutation. And a group of experts in the field are lauding the results, saying that the success of this study could help pave the way to one of the first new skin cancer therapies in some 20 years.
Of the 16 terminal patients who share a mutation of the BRAF gene, 10 taking PLX4032 saw their tumors shrink and one witnessed its disappearance--a 69 percent response rate among the drug group. The other 39 patients in the group did not have the genetic mutation and all saw their cancers progress. In a second group, 81 percent with the mutation experienced a positive response. The drug blocks the BRAF protein and the same mutation is believed to appear in 40 percent to 60 percent of all skin cancer patients.
"I have been treating patients with melanoma for 20 years, and I've never seen a drug response like this," Lynn Schuchter, Penn's chief of hematology-oncology, told the Philadelphia Inquirer. "Some patients responded in just 72 hours, going off pain meds." The upbeat study outcome was a triumph for the investigators involved. After the initial doses of PLX4032 failed to generate a response, the researchers reformulated the drug to make it easier for patients to absorb.
"Metastatic melanoma has a devastating prognosis and is one of the top causes of cancer death in young patients," said lead author Keith Flaherty. "Until now, available therapies were few and unreliable, so these findings can really change the outlook for patients whose tumors are fueled by this mutation."