SCIENCE IN THE NEWS DAILY
Melanoma Drug Combo Packs a One-Two Punch
from ScienceNOW Daily News
Drug resistance is the bane of cancer researchers and patients. But early results from a new clinical trial suggest a way to get around a tumor's defenses. By combining high doses of two new drugs against advanced melanoma, scientists were able to delay for months the cancer's ability to evade the therapy aimed at a tumor's molecular weak spot.
The trial is testing a so-called BRAF inhibitor, a widely heralded new type of melanoma drug. It targets a growth-spurring protein, BRAF, encoded by a mutation in the BRAF gene that occurs in about half of melanoma patients. Although the drug extends patients' lives--on average they live 14 to 15 months, versus 8 months on conventional therapy--their tumors eventually develop resistance and begin growing again. Often the tumors restore the BRAF growth pathway by turning on a downstream protein called MEK, suggesting that combining a MEK inhibitor and a BRAF inhibitor could stave off cancer growth longer.
That strategy now shows signs of working, according to data released today in advance of the annual meeting of the American Society of Clinical Oncology (ASCO) in Chicago, Illinois, from 1-5 June. In 77 patients who took a BRAF inhibitor and a MEK inhibitor made by GlaxoSmithKline, the drugs shrank tumors or delayed growth by 7.4 months on average--no longer than has been reported for the BRAF inhibitor alone. But the results were more encouraging for 24 patients who received the highest doses of the two drugs. Their tumors became stable or shrank and did not resume growing for 10.8 months on average.