UPDATE 1-Astra gets Crestor boost ahead of key patent trial

* Expanded U.S. label differentiates AstraZeneca drug

* Next challenge is Feb. 22 U.S. patent trial

* Judgment expected in patent case before end July

* Shares gain 2.2 percent for hopes for higher sales

(Adds details on patent case, further analyst comment)

By Ben Hirschler

LONDON, Feb 9 (Reuters) - AstraZeneca (AZN.L) has pulled ahead of the pack with an expanded label in the United States for its heart drug Crestor, but the medicine's future remains uncertain ahead of a vital patent trial this month.

Shares in the Anglo-Swedish drugmaker jumped 2.2 percent on Tuesday, outperforming a flat European drugs sector .SXDP, as investors welcomed the broad label to promote Crestor for preventing heart disease in people with normal cholesterol but other heart risks. [ID:nN08212098]

Crestor is the only cholesterol-lowering statin drug approved for such use and AstraZeneca believes this will allow it to maintain the strategic high ground, despite fierce competition.

Differentiating Crestor as the medicine best suited for patients with multiple risk factors will be even more important from November 2011, when Pfizer's (PFE.N) best-selling Lipitor drug goes off patent.

AstraZeneca's sales of Crestor are forecast to reach $6.5 billion in 2013, up from $4.5 billion in 2009, according to consensus estimates from Thomson Pharma, making it the company's most important sales driver.

MILLIONS MORE PATIENTS

In theory, extending Crestor's use to people with normal cholesterol and raised levels of C-reactive protein (CRP) could add some 6.5 million patients in the U.S. alone, adding billions of dollars to sales of the $4-a-day drug.

In practice, however, testing for CRP levels is still not widespread and analysts said much of the sales benefit may already have been seen, since clinical trial results supporting the new label have been known for more than a year.

At the same time, a question-mark hangs over the main patent protecting Crestor from cut-price generic competition.

"It's CPR (Crestor Patent Risk), not CRP that requires more attention," Jeffrey Holford, a pharmaceuticals analyst at Jefferies, said in a research note.

The U.S. District Court for Delaware will hear the Crestor patent case at a trial starting on Feb. 22, with a total of 10 days has been set aside for the trial.

A verdict is expected later in the year. Judge Joseph Farnan told a pre-trial conference last week he intended to decide the case prior to his retirement at the end of July.

Most analysts think AstraZeneca will prevail, although the case is far from clear cut.

AstraZeneca tried and failed last year to win a summary judgment that would have eliminated the most significant issue -- alleged inequitable conduct -- from the case.

The main U.S. patent protecting the medicine until 2016 is being challenged by a group of generics manufacturers including Apotex, Aurobindo (ARBN.BO), Cobalt, Mylan (MYL.O), Par, Sandoz (NOVN.VX) and Sun (SUN.BO).

AstraZeneca's action against all seven generic firms has been consolidated in the Delaware case. There was a subsequent challenge from Teva (TEVA.TA) in June 2008.

(Editing by Sharon Lindores)