* Now approved in US for 5 different cancer types
* Kidney cancer is US's 8th most commonly diagnosed cancer
* Shares down 2.1 pct, weaker than index
(Adds background, updates stock)
By Katie Reid
ZURICH, Aug 3 (Reuters) - Roche Holding AG's (ROG.VX) cancer drug Avastin has won approval from the U.S. Food and Drug Administration (FDA) for the treatment of the most common type of kidney cancer, the Swiss drugmaker said on Monday.
The FDA approval gives the green light to treat metastatic renal cell carcinoma using Avastin plus interferon alpha, based on data from a Phase III study in patients with the advanced, previously untreated condition, Roche said.
The study showed that patients who were treated with Avastin plus interferon alpha lived nearly twice as long without their disease getting worse than those who received interferon alpha alone, the group said.
"The approval was expected, and we estimate that it could increase revenues by 300-500 million francs. We have already factored 400 million francs into our Avastin assumptions," said Vontobel analyst Silvia Schanz in a note.
By 1256 GMT, Roche stock, which has rallied in recent weeks after it raised its outlook, was trading 2.1 percent lower at 164.90 Swiss francs, compared with a flat European pharmaceuticals sector .SXDP.
Avastin, which works by starving tumours of blood supply and is made by Roche's recently acquired Genentech unit, is also used to treat lung, colon and breast cancers, and had annual global sales of 5.2 billion Swiss francs ($4.86 billion) in 2008.
In the new kidney cancer setting Avastin will face "intense" competition from Pfizer's (PFE.N) Sutent, Bayer BAYG.DE and Onyx's ONXX.O Nexavar, and Wyeth's WYE.N Torisel, Helvea analysts said in a note.
"(These drugs) have carved out a large share of the market on strong data as single-agent therapies, i.e. without the use of toxic interferon. Nevertheless, Avastin is believed capable of making inroads into the market," they said.
Kidney cancer is the eighth most commonly diagnosed cancer in the U.S., according to the American Cancer Society. Around 13,000 Americans will die from the disease in 2009.
Avastin has been available in Europe since the end of 2007 for the first-line treatment of patients with advanced and/or metastatic renal cell cancer in combination with interferon alpha.
"Avastin has now been approved for five different types of cancer in the USA," William Burns, chief executive of Roche's Pharmaceuticals Division, said in a statement.
"This underscores our belief in the important clinical benefits that Avastin delivers as we push forward with our ongoing research programs in more than 30 tumour types."
Swiss brokerage Kepler Capital Markets raised its price target to 186 francs from 173 francs and confirmed its buy rating in the wake of Roche's first-half results and recent drug pipeline news.
"With recent supportive drug news... the innovation engine is fully running, with more momentum to come in the second half, (such as) Avastin in ovarian cancer, taspoglutide in diabetes," analyst Daniel Daetwyler said in a note.
Last month Roche gave a bullish forecast for the next two years, raising its earning guidance as a result of the Genentech deal. [ID:nLM233133] ($1=1.070 Swiss Franc) (Editing by Will Waterman and Mike Nesbit)