* Diagnostic test to target drug to patients also approved
* Roche to charge $56,400 for course of treatment in U.S.
* Analyst sees peak sales of Zelboraf at $1.5 bln
* Roche shares up nearly 2 pct on Swiss stock exchange (Adds foundation, analyst comment, price, details)
WASHINGTON, Aug 17 (Reuters) - U.S. drug regulators approved a targeted skin cancer drug from Roche Holding (ROG.VX), offering new hope for patients with the deadliest form of cancer after years of few options.
The U.S. Food and Drug Administration was two months ahead of schedule in approving the drug, under the brand name Zelboraf, along with a companion diagnostic test that identifies which patients have a specific genetic mutation that means they will benefit from the treatment.
Zelboraf was developed in partnership with Daiichi Sankyo (4568.T) and is the second drug to be approved for melanoma this year, after Yervoy from Bristol-Myers Squibb(BMY.N). Prior to 2011, the FDA had not approved a new melanoma drug in 13 years.
Both are expected to top $1 billion in sales for their manufacturers, and analysts at Sanford Bernstein predict that Yervoy will capture 60 percent of the U.S. market versus 40 percent for Zelboraf.
"The FDA's quick action on this drug approval is important because it gives melanoma patients a new way to fight this deadly disease," said Timothy Turnham, executive director of the Melanoma Research Foundation, about the Roche drug.
"We have seen evidence that targeting gene mutations works. But it also demonstrates the very real challenges researchers still face in offering patients lasting results."
Advanced melanoma patients taking the Roche twice-daily pill were 63 percent less likely to die from the disease than patients given chemotherapy. However, some patients eventually become resistant to Zelboraf.
"The FDA clearly made it a priority to approve Zelboraf based on the strong clinical data," said Helvea analyst Karl-Heinz Koch. "Roche will now get the sales from this drug earlier and that's going to be a bonus for the stock in the second half of the year.
Vontobel analyst Andrew Weiss sees Zelboraf peak sales of 1.2 billion Swiss francs ($1.5 billion).
Shares in Roche rose 1.7 percent in Zurich. Bristol gained 0.5 percent in New York trading.
Melanoma globally afflicts nearly 160,000 new people each year. It can spread quickly to internal organs and average survival is six to nine months.
Roche estimates that around 9,500 of the 70,000 new cases of melanoma expected to be diagnosed in the United States this year will be advanced forms of the skin cancer.
Zelboraf, known clinically as vemurafenib, is designed for patients with tumors that have a mutation in a gene known as BRAF that allows melanoma cells to grow. About half of all melanomas have the genetic aberration the drug targets.
Yervoy, or ipilimumab, sold more quickly than expected after its approval in March. It is an antibody designed to spur the immune system to fight off the melanoma.
The 10 percent of patients who respond to Yervoy often get benefit that can last for many years, in contrast to the relatively short-lived effect of Zelboraf.
While the drugs will compete for market share, Roche and Bristol are also collaborating on a novel clinical trial to see if a combination of the two will yield a more effective treatment for some patients. [ID:nN02237555]
Roche said Zelboraf would cost about $56,400 for a six-month course of treatment in the United States. Bristol's Yervoy costs $120,000 for a course of treatment. The diagnostic test will cost around $150, according to Paul Brown, president of Roche Diagnostics.
Side effects from Zelboraf include rash, slight hair loss, extreme photosensitivity and joint pain.
Roche filed for U.S. approval of the drug in April and the FDA had to make a decision by Oct. 28. Reuters reported on Aug. 10 that an early nod was likely. [ID:nN1E77917U] The medicine is the first new oncology product from Roche's Genentech unit since 2004's launch of lung cancer drug Tarceva. (Additional reporting by Katie Reid; editing by Michele Gershberg, Dave Zimmerman and Gunna Dickson)