Uveal (ocular) melanoma is a difficult-to-treat type of melanoma found in the eye. Remarkably resistant to chemotherapy and prone to metastasis, it is often treated with surgery and/or radiation. Earlier this year, I wrote about new scientific findings that could lead to new targeted treatments for uveal melanoma. These would take advantage of abnormal molecular characteristics of tumor cells. Now, another targeted drug called selumetinib has entered the spotlight. It was recently tested in patients in a clinical trial with promising results. Continue reading…
“Researchers at the University of California, San Diego School of Medicine have identified a therapeutic target for treating the most common form of eye cancer in adults. They have also, in experiments with mice, been able to slow eye tumor growth with an existing FDA-approved drug.
“The findings are published online in the May 29 issue of the journal Cancer Cell.
” ‘The beauty of our study is its simplicity,’ said Kun-Liang Guan, PhD, professor of pharmacology at UC San Diego Moores Cancer Center and co-author of the study. ‘The genetics of this cancer are very simple and our results have clear implications for therapeutic treatments for the disease.’ “
Editor’s note: More and more, oncologists are using molecular testing to look for genetic mutations that may allow a tumor to be fought with a drug targeted for a specific mutation. In this study of uveal melanoma, scientists found two mutated proteins that suggested a drug called verteporfin might be effective. They tested the drug in mice and found that it suppresses the growth of uveal melanoma tumors derived from human tumors. It will probably be a while before the treatment is okay-ed for use in humans, but the investigational process might be quicker than is usual for new treatments because verteporfin is already FDA-approved to treat another eye condition.
“Gq/11 mutations are early oncogenic events in UM resulting in MAPK pathway activation. We demonstrated decreased viability in UM cell lines harboring Gq/11 mut with sel, a small molecule inhibitor of MEK1/2 (Ambrosini, CCR 2012).”
About half of melanomas that start in the eye spread to other parts of the body, usually killing people within a year. But while there are a variety of therapies for melanomas in the skin, those in the eyes are biologically distinct and there has been no good way to treat them—until now. A clinical trial of 157 people showed that a drug called selumetinib can shrink melanomas of the eye, which form in a layer called uvea that includes the iris. Selumetinib is a MEK inhibitor that targets the most common uveal mutations (GNAQ and GNA11). The researchers found that tumors shrank in in half of those treated with selumetinib and did not grow again for twice as long compared to those treated with standard chemotherapy (an average of 16 vs 7 weeks). This work was presented at the American Society of Clinical Oncology’s 2013 meeting.