By Anuron Kumar Mitra and Tamara Mathias

(Reuters) – The U.S. Food and Drug Administration said on Wednesday it approved Array BioPharma Inc’s oral combination treatment for use in patients with the deadliest form of skin cancer.

The combination therapy, which consists of encorafenib and binimetinib, was approved based on the company’s late-stage trial, whose results were released earlier this month.

It showed that half the patients treated with the combination survived advanced melanoma with a common gene mutation called a BRAF mutation nearly three years after the treatment.

This was in comparison to Roche Holding AG’s study of Zelboraf, a drug that is commonly part of standard-of-care regimens, which showed a median overall survival of 16.9 months observed in patients.

Cantor Fitzgerald analyst Mara Goldstein expects peak sales in the $500 million range for the combination drug.

The treatment, dosed as 450 milligrams of encorafenib once daily and 45 mg of binimetinib twice a day, gives Array its first marketable regimen.

About 91,270 new cases of melanoma will be diagnosed and about 9,320 people are expected to die of it in the United States in 2018, according to the American Cancer Society.

Currently, there are limited treatment options for patients, who are generally cycled through a course of targeted treatments or are administered immunotherapies that harness the body’s immune system to recognize and kill cancer.

Array’s approval will help fill a critical unmet need for patients with advanced BRAF-mutant melanoma, its Chief Executive Officer Ron Squarer said in a statement.

Rival Novartis AG already has an approved combination in the market and a trial testing of its Tafinlar and Mekinist showed nearly 30 percent of patients were still alive after five years.

Array’s shares, which have more than doubled in the past twelve months, were down 3.7 percent at $17.82 in afternoon trading.

(Reporting by Tamara Mathias and Anuron Kumar Mitra in Bengaluru; Editing by Anil D’Silva and Arun Koyyur)