Zelboraf Side Effects Linked to Risk of Squamous Cell Carcinomas

Roche’s melanoma skin cancer pill Zelboraf, actually appears to cause other, less deadly, forms of skin cancer to grow, some researchers report. 

In a new study published this week in the New England Journal of Medicine, researchers from the Johnson Comprehensive Cancer Center at the University of California, Los Angeles, indicate that Zelboraf side effects appears to trigger growth of squamous cell carcinomas, a secondary form of skin cancer. However, the researchers say there may be a fix by combining Zelboraf with other drugs.

Researchers performed a molecular analysis on mutated skin cells from patients treated with Zelboraf (vemurafenib), which belongs to a class of drugs known as BRAF inhibitors. They found that while Zelboraf blocks mutations leading to the growth of melanoma cancer cells, it causes other skin cancer cells’ growth to accelerate.

The researchers say that their findings seem to indicate that when Zelboraf is combined with a drug called an MEK inhibitor, the combination could block the growth of both types of skin cancer cells. However, the researchers cautioned that the premise needs to be proven in clinical trials.

GlaxoSmithKline is reportedly in the process of conducting such clinical trials.

The American Cancer Society indicates that melanoma is diagnosed in about 69,000 Americans each year and causes about 8,650 deaths annually. Less dangerous, but more common, basal and squamous cell carcinomas affect more than one million Americans each year and cause about 2,000 deaths annually.

Such skin cancers are most commonly seen among older people, but in recent years there have been an increasing number of young women diagnosed with skin cancer, especially on the trunk and extremities. This has largely been believed to be caused by increases in the use of tanning beds.

A study by the World Health Organization in July 2009, indicated that use of tanning beds before the age of 30 may increase the risk of skin cancer by 75%. As a result of the study, WHO reclassified ultraviolet radiation from tanning beds as a definite carcinogen . Previously, they were considered “probable” carcinogens.

There have been increasing calls for a ban on the use of tanning beds for children under the age of 18. In March, the American Academy of Pediatricians (AAP) called for such a ban and an FDA advisory committee made similar recommendations in March 2010.