Study Shows Drug Combination Could Treat Uveal Melanoma

A new study from the Huntsman Cancer Institute (HCI) has revealed that a drug combination that was previously shown to stop tumor growth in pancreatic cancer has also shown promise at targeting uveal melanoma, the most common type of eye cancer.

Researchers from HCI, associated with the University of Utah, treated mice infected with uveal melanoma using two drugs—trametinib and hydroxychloroquine. The drug combination activated a cascade effect that caused tumor cell death and impeded tumor growth.

While the research was conducted in mice and still needs to be tried in humans, the initial results are promising.

“We know that there is good safety and tolerability data on each of these two medications individually and studies would have to assess the combination of effect in large clinical trials,” Prithvi Mruthyunjaya, MD, an associate professor of ophthalmology at Stanford University Medical Center who was not involved in the study, tells Verywell.

Mruthyunjaya, adds, “Being able to stop the cancer at multiple points in its growth potential is critical to inducing tumor death, which can make a significant improvement in survival for our patients."

What Is Uveal Melanoma?

According to the Ocular Melanoma Foundation (OMF), uveal melanoma (also called ocular melanoma or eye melanoma) is the most common primary eye cancer in adults. It occurs in the uveal tract of the eye, which includes the iris (the colored part of the eye). 

While it is not the same as skin melanoma, there are some similarities. Both types of melanoma are caused by cancerous melanocytes, a type of cell found in the skin, hair, and the lining of our internal organs, as well as in the eye.

UV tumors are often malignant. Uveal melanoma will spread (metastasize) to the liver in about 50% of people with the type of cancer. When it spreads to the liver, it can prove fatal.

“Treatment of late-stage or metastatic uveal melanoma continues to be a challenge,” says Mruthyunjaya. “The mainstay of therapy is a combination of systemic agents, and also localized infusion of chemotherapy into the affected organs like the liver.”

Diagnosis and Treatment

Most cases are discovered during a routine eye exam, which is one reason having an annual exam is important. If uveal melanoma is suspected during a routine eye exam, the diagnosis can be made without a biopsy. From there, an eye specialist will determine the patient's prognosis and treatment options using the following criteria:

• How the melanoma cells look under a microscope
• The size and thickness of the tumor
• The part of the eye the tumor is in (the iris, ciliary body, or choroid)
• Whether the tumor has spread within the eye or to other places in the body
• Whether there are certain changes in the gene linked to intraocular melanoma
• The patient's age and general health
• Whether the tumor has recurred (come back) after treatment

Uveal melanoma is a rare type of cancer, making treatment challenging. According to the NCI, there are currently five standard treatments available to patients:

• "Watchful waiting" (where the patient is carefully looked after by their healthcare provider, but they do not choose a specific treatment)
• Surgery
• Radiation therapy
• Photocoagulation
• Thermotherapy

Future Research

Research on the mechanisms of uveal melanoma as well as exploring new treatment options through clinical trials has become more prevalent in the last couple of years, but there is still a lot of work needed to understand how to prevent and treat this form of cancer.

“Though a lot of work is being done, the bar is still low for treatment options for our patients,” Mruthyunjaya says. “There have been promising clinical trials utilizing novel technologies that may hold promise for the future.”