Data on Astra's Crestor drug vs Lipitor seen soon
* Headline results could be imminent - Bernstein
* Trial completed, AZ aims for full presentation in Nov
* Head-to-head study critical as Lipitor goes off patent
PARIS, Aug 31 (Reuters) - Headline results from an important clinical trial comparing AstraZeneca's cholesterol fighter Crestor to Pfizer's Lipitor could be released imminently, according to an analyst note on Wednesday.
An AstraZeneca spokesman confirmed to Reuters the trial was complete, with the last patient visit having taken place. The company is targeting a presentation of the full results at the annual meeting of the American Heart Association in November.
That timetable means it is possible AstraZeneca will also pre-announce "top-line" results for the study in the coming weeks, since drugmakers often give a short summary of clinical trials when the results are deemed to be material.
Tim Anderson of Bernstein thinks this is likely to be the case with the head-to-head study of Crestor and Lipitor. "We think an update could come soon," he said in a note to investors.
The outcome of the so-called Saturn study is keenly awaited as it will show if AstraZeneca's drug is better, worse or equivalent to Lipitor, just as the Pfizer medicine is about to go off patent. The study measures changes in plaque levels in coronary arteries using ultrasound imaging.
Anderson believes AstraZeneca's pill has a 65 percent chance of coming out better than Lipitor, a 30 percent chance of being equivalent and a 5 percent chance of doing worse.
Since Crestor is widely perceived to be the most effective of the statin medicines for reducing "bad" LDL cholesterol, as well as having a beneficial effect on "good" HDL cholesterol, a good result would help cement its market position.
But equivalence or inferiority to Lipitor in the AstraZeneca-sponsored study would dent confidence in its prospects, just as Lipitor is about to face competition from cheap generic copies in the U.S. market from the end of November.
"If Saturn doesn't show a clear benefit in favour of Crestor, payers could push back even harder against usage of the drug downstream of Lipitor generics," Anderson said.
Crestor is AstraZeneca's biggest-selling drug, with 2010 sales of $5.7 billion. By 2015, Bernstein expects it to sell around $6.9 billion -- subject to any setback as a result of the Saturn study -- which would mean it accounts for a quarter of company revenue and more than half of profits.
For a previous analysis on Crestor's prospects see (Reporting by Ben Hirschler; Editing by Will Waterman)