Melanoma Drug’s Link to Other Skin Cancers
The recently approved drug vemurafenib (Zelboraf) has been hailed as a breakthrough in the treatment of melanoma, the deadliest form of skin cancer. But roughly one-quarter of patients who take the medication develop a troublesome side effect: secondary skin cancers called squamous cell carcinomas.
Now, a new study by researchers at the Jonsson Comprehensive Cancer Center at the University of California, Los Angeles, and colleagues identifies the specific genetic mechanism that causes this side effect.
"What we found is that vemurafenib blocks the mutation that makes the melanoma grow, but when patients have skin cells with another mutation that’s probably induced from sun exposure, there the drug has the exact opposite effect and causes these squamous cell cancers to grow," said Dr. Antoni Ribas, co-senior author of the study and an associate professor of hematology/oncology at UCLA.
What’s more, the findings suggest that combining vemurafenib, a BRAF inhibitor, with a drug called an MEK inhibitor — which blocks the other mutation — may not only prevent this side effect, but may also lead to an even more effective melanoma treatment, Ribas said.
"It needs to be demonstrated in clinical trials, but the theory is that if we give these two medications together up front, we will be punching the melanoma where it really hurts twice, and also preventing the growth of secondary skin cancers," Ribas said.