AstraZeneca shares have performed strongly since March, outpacing the European sector by around 30 percent, as the company has successfully seen off the immediate threat of generic competition to Nexium and Seroquel. Investors are also hopeful that new clinical trial data on Crestor, due to be presented at the annual meeting of the American Heart Association next month, will help differentiate the medicine in a crowded cholesterol market. But the shares still trade on a lowly 8.25 times forecast 2009 earnings -- below British rival GlaxoSmithKline on nearly 11 times -- reflecting investor concern about the company's relatively thin late-stage drug pipeline.