AstraZeneca (AZN) reported third-quarter results that largely matched our expectations, and we don't anticipate any changes to our fair value estimate. Total sales fell operationally by 2% year over year because of continued generic competition on key drugs and the absence of H1N1 vaccine sales that boosted the top line a year ago. Earnings per share fell faster than sales, declining 10% from the prior-year period largely because of the asset-impairment charge related to discontinuing studies on lesogaberan for acid reflux disease. Astra increased the low end of its full-year earnings outlook by 2%, to $6.50-$6.65 per share; we expect it will hit the top of the range.
Cardiovascular drug Crestor led Astra's sales in the quarter. In line with our projections, Crestor increased 20% year over year as new indications are supporting sales growth. We continue to project strong double-digit growth for Crestor over the next two years on the basis of the drug's perceived best-in-class efficacy. The majority of the company's other top drugs posted gains that largely matched our estimates. As we expected, generic competition weighed on several of the company's mature drugs, including cancer drug Arimidex, respiratory drug Pulmicort, and cardiovascular drug Toprol-XL. We expect generic competition will be a drag on growth for several years as Astra faces one of the worst patent cliffs in the industry.
We believe cardiovascular drug Brilinta represents the company's most important new drug. Based on strong clinical data, we peg the probability of approval for the drug at 80% with the approval potentially coming by the end of the year. We estimated the drug will develop into a major blockbuster. While Astra discontinued the development of acid reflux disease drug lesogaberan, we had only projected peak annual sales of less than $100 million, which limits the effect of the drug's exit on the company's valuation.
The majority of costs were flat year over year as a percentage of total sales. Excluding one-time charges in the cost of goods sold line, operating margins were similar to the prior-year period. While we expect further cost-cutting by Astra will help mitigate the loss of high-margin drugs, we project slight margin erosion over the next several quarters.