MONDAY, Jan. 30 (HealthDay News) -- The U.S. Food and Drug Administration on Monday approved a drug to treat the most common form of skin cancer, basal cell carcinoma.

Erivedge (vismodegib) is the first drug sanctioned in the United States to treat basal cell skin cancer that has metastasized, or spread. The once-daily pill is also designed for cases deemed unsuitable for surgery or radiation, the agency said in a news release.

This usually slow-growing, painless form of cancer starts in the epidermis, the top layer of skin. Frequent exposure to sunlight and other forms of ultraviolet radiation are the typical causes, the FDA said.

Researchers evaluated the safety and effectiveness of Erivedge in a clinical study of 96 people with locally advanced or metastatic cancer. Of those with metastatic disease, 30 percent had at least a partial response to the drug, while 43 percent of people with locally advanced basal cell had at least a partial response.

One specialist welcomed the drug's approval.

"Eviredge is an amazing revolutionary approach to treating skin cancer," said Dr. Michele Green, dermatologist at Lenox Hill Hospital in New York City. "I have many patients who are elderly and infirm for whom getting surgery is a major ordeal. Molecular biology has advanced to the point where such an important advance in therapy was unthinkable even a few years ago."

Skin cancer is the most commonly diagnosed cancer in the United States, and it is estimated that one in five Americans will develop it in their lifetime. Caught early, it is highly treatable.

The most frequently cited side effects of Erivedge included muscle spasms, hair loss, weight loss, nausea, diarrhea, fatigue, distorted sense of taste, decreased appetite, constipation and vomiting.

Because of the potential risk for death or severe birth defects to a fetus, the drug will be packaged with a label warning, and doctors will not prescribe it to women who are pregnant, the agency said. Men and women will be advised to use birth control while taking the pills.

Erivedge, marketed by San Francisco-based Genentech, won expedited approval under a priority review program for drugs that may represent a major treatment advance.

More information

The Skin Cancer Foundation has details about basal cell.