Lung Cancer Drugs Override Resistance to Melanoma Therapies in Early Tests
Gefitinib and dasatinib help block faulty cell signaling (Feb. 11)
Adding lung cancer drugs to targeted melanoma treatment could increase survival for certain patients, according to new research published in Cancer Discovery.
Scientists at the University of Manchester in the U.K. have shown that lung cancer drugs, such as gefitinib (Iressa, Astra Zeneca) and dasatinib (Sprycel, Bristol-Myers Squibb), can override resistance to BRAF inhibitors (new targeted therapies for melanoma).
BRAF inhibitors, such as vemurafenib (Zelboraf, Genentech), work by targeting a faulty version of the BRAF protein, which is found in more than half of all melanomas as well as in some other types of cancer. But patients often become resistant to these drugs after a short period, and their disease returns, leaving them without further treatment options.
Now researchers have found that treating BRAF inhibitor-resistant tumors with gefitinib or dasatinib, which block a different biological pathway, can halt tumor growth.
“If these findings are confirmed in larger studies, combining two drug types could provide an effective new treatment for skin cancer patients for whom the only existing targeted treatment available — vermurafenib — no longer works,” said lead author Professor Richard Marais.
According to the researchers, some melanoma cancer cells respond to BRAF-inhibitor resistance by turning on a biological pathway called EGF signaling. This drives cancer via a different cell-signaling route. The combination of BRAF inhibitors and drugs that target EGF signaling — including gefitinib and dasatinib — blocks these two faulty cell-signaling routes simultaneously, thereby arresting the growth of cancer cells.
Source: Cancer Research UK; February 11, 2013.