LONDON -- For a company that's perennially attracting criticism of its meager new drugs pipeline, AstraZeneca (LSE:AZN) (NYSE:AZN) has enjoyed a good run in recent times.

Just last week, for instance, the shares reached a 52‑week high of 3,383 pence, and are up 15.1% since the start of the year -- a performance that contrasts sharply with the FTSE 100's more modest 5.4% increase.

Over the longer term, too, the shares have done decently. On a five-year view, for instance, the FTSE 100 has gained just 5.5%. AstraZeneca, meanwhile, has surged 61%.

Total return
As a holder of AstraZeneca shares, I'm naturally gratified -- even though the timing of my own purchases means that my gains aren't quite on this scale.

Nevertheless, on a total return basis, I can't complain: Again and again, AstraZeneca's impressive yield has delivered a decent dividend on top of the capital gains that I've experienced. Even today, for instance, with the shares close to a 52-week high, AstraZeneca still offers a forecast yield of 5.5% -- well above the FTSE's average yield of 3.6%.

But is it time to think of selling, in order to bank those gains and seek a better return elsewhere? Because -- odd though that may sound, given AstraZeneca's record -- the underlying news flow hasn't really changed.

Dark clouds
Simply put, when it comes to AstraZeneca, investors have much to be nervous about.

Take the number of drugs coming off patent, which leaves the company highly vulnerable to generic competition. Revenues for 2012 of 27.9 billion pounds, for instance, are well down on the 33.6 billion pounds of 2011, and the 33.3 billion pounds of 2010. Worse, forecasts for 2013 and 2014 are sharply lower still.

Attempts to buy in fresh blockbusters have thus far largely failed: The company is regarded as having overpaid for biopharmaceutical business MedImmune in 2007, for instance.

And having repeatedly resisted investors' calls for a radical shake-up, AstraZeneca's then-CEO David Brennan abruptly quit a year ago, in the wake of a series of setbacks regarding the drug pipeline. This Thursday, Brennan's replacement, Pascal Soriot -- recruited from Swiss rival Roche -- will preside over his first AstraZeneca AGM, and investors will be looking keenly to see signs of progress.

Having got off to a good start by canceling the share buyback program, in order to put the money into drug development instead, the news flow since has been warm but hardly riveting. More focused research; accelerated cost-cutting; better marketing of existing drugs -- all good stuff, to be sure, but hardly equal to a clutch of solid blockbusters.

Silver linings
That said, I'm in two minds about selling.

For one thing, turnarounds in the pharmaceutical industry take time: Drugs can't be developed to order, or pipelines kick-started overnight. Soriot knows what he has to do -- and cutting and running before he can show if he can deliver it seems stupid.

And best of all, perhaps, is AstraZeneca's continued lowly rating and high yield. Today, for instance, the company trades on a forecast P/E of under ten -- well below the FTSE 100's P/E of almost 14.

In other words, even a return to a purely average rating would represent a 40% uptick on today's share price -- which itself is just shy of a 52-week high.

Follow the money
One investor who rates AstraZeneca is investing legend Neil Woodford, who has a major stake in the business. And with 21 billion pounds under management, coupled to a track record of comfortably outstripping the returns from the market as a whole, his is a voice worth listening to.

Over the past five years, for instance, Woodford's Invesco Perpetual High Income fund has returned precisely double the return from the FTSE All-Share index. And an investor putting 10,000 pounds into his High Income fund back in 1988 would have seen it grow to 193,000 pounds today -- that's quite some return.

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