AstraZeneca’s earnings for the third quarter have been hit hard by generic competition to Toprol XL and charges but the Anglo-Swedish drugmaker can take comfort from the fact that its five key products continue to perform well.

Operating profit fell 7% to $2.02 billion, better than analysts’ estimates, but would have been flat were it not for $146 million of restructuring costs and $212 million relating to the firm’s acquisition of MedImmune. Revenues were up 10% to $7.15 billion, though sales of its biggest-seller, the gastrointestinal drug Nexium (esomeprazole), actually slipped 1% to $1.29 billion.

Chief executive David Brennan said on a conference call that AstraZeneca continues to grow its market share of the branded proton pump inhibitor market “but it isn't enough at this stage to offset lower prices and the growth of generic omeprazole,” ie copycat versions of the firm’s Prilosec/Losec.

However, the cholesterol-lowerer Crestor (rosuvastatin) put in another stellar performance rising 25% to $691 million, and the drug’s launch in Japan in August has gone well. The firm had little to add about the generic challenge to Crestor announced earlier in the day by Canada’s Cobalt Pharmaceuticals, saying that it is confident of demonstrating the validity of its patents and will defend them vigourously. Still, news of the challenge seemed to panic investors and the firm’s shares fell 1.8% to £23.30.

As for the other three key products, Seroquel (quetiapine) for schizophrenia advanced 22% to $1.06 million, the first time sales of the drug have passed the billion dollar mark in a quarter, while breast cancer drug Arimidex (anastrozole) rose 7% to $425 million. The firm’s combination product for asthma - Symbicort (budesonide and formoterol) – brought in $371 million, up 25%, boosted by its US launch at the end of June.

On the negative side, sales of the blood pressure drug Toprol XL (metoprolol), sold as Seloken in some markets, sank 33% to $328 million and were down 43% in the USA as generic competition hit hard. MedImmune’s paediatric vaccine for respiratory syncytial virus Synagis (palivizumab) contributed $122 million, up 9%, but AstraZeneca pointed out that the “highly seasonal” nature of the product means that majority of its sales will be recorded in the fourth and first quarters.

Mr Brennan said that “the business is on track to meet its earnings target for the full year,” of $3.60 to $3.75 per share, excluding sales of Toprol XL and restructuring costs, which will be some $900 million, or $0.44 per share. He added that “the entire organisation is driving for increased productivity and the pipeline has been further strengthened during the quarter.” Ten compounds are currently in Phase III trials. By Kevin Grogan