Panmure Gordon has retained its 'hold' rating and 3,200p target price for biopharmaceutical group AstraZeneca, but celebrated the company's 560m-dollar acquisition of Pearl Therapeutics on Monday, a necessary move in the broker's opinion.The firm announced that it has entered into an agreement to buy Pearl, a California-based company focused on the development of inhaled small-molecule therapeutics for respiratory disease. Pearl's lead product, PT003, is a potential new treatment for chronic obstructive pulmonary disease (COPD), currently in late-stage development. While it is too early to gauge the commercial prospects of PT003 - the product wouldn't be filed for registration until 2015 and wouldn't start contributing to earnings until 2018 - Panmure said that Astra has "bag[ged] a beaut"."Some might choke on the price of the asset, but to us AstraZeneca's acquisition of Pearl Therapeutics was strategically important and had to be done," said analyst Savvas Neophytou.He said that Astra's respiratory business represents just 16% of revenues and its pipeline was "threadbare"."Today's acquisition does not result in changes to forecasts but with one big hole plugged, we are warming to the story once more. We re-iterate our 'hold' recommendation for the time being."The broker said that the stock has had a good run recently - up nearly 10% over the last three months and 14% so far this year - and is "up with events currently".Astra's valuation is still at a hefty discount to the wider large-cap European pharma sector, but Panmure thinks this is warranted given its "perceived increased forecast risk".The share price was up 0.77% at 3,327p by 10:39 on Monday.