AstraZeneca has posted an 18% decline in revenues to $6.66 billion, due to the loss of exclusivity on key brands, notably the antipsychotic Seroquel, and tough market conditions.

Core operating profit was down 27% (at constant exchange rates) to $2.27 billion, hit by a 57% decline in the Seroquel (quetiapine) franchise to $647 million. Seroquel IR, which lost patent protection in March, sank 75% to $277 million.

Revenues for Nexium (esomeprazole) were down 13% to $949 million and as for the Anglo-Swedish drugmaker's oncology products, Arimidex (anastrozole) fell 16% to $147 million, battered by patent expiries. Casodex (bicalutamide) fell 13% to $118 million, while Zoladex (goserelin) brought in $275 million (-6%). However, Iressa (gefitinib) climbed 13% to $154 million and Faslodex (fulvestrant) leapt 24% to reach $161 million.

AstraZeneca's biggest-seller, the cholesterol blockbuster Crestor (rosuvastatin) decreased 5% to $1.59 billion, largely due to loss of exclusivity in Brazil and Canada. The company said sales of the drug "have been resilient in the face of a highly genericised statin market", not least since the arrival of generic Lipitor (atorvastatin) in the USA. However in the latter, Crestor slipped back just 1%.

The asthma combo Symbicort (budesonide and formoterol) rose 3% to $795 million, while the Onglyza (saxagliptin) diabetes franchise partnered with Bristol-Myers Squibb, brought in $79 million, up 72%. The recently-launched antiplatelet drug Brilique/Brilinta (ticagrelor) had sales of just $18 million.

Geographically, sales in western Europe fell 20% and were down 29% in the USA. Turnover inched up 1% in emerging markets to $1.41 billion.

However, interim chief executive Simon Lowth said that despite challenges, "we are on track to achieve our financial targets for the full year." He added that the results "reflect the resilience of several of our brands and the benefits of disciplined cost management".

Mr Lowth mentioned the deal with Bristol-Myers Squibb which will in effect see the firms jointly acquire Amylin Pharmaceuticals for $7 billion, describing it as "an exciting opportunity to expand our diabetes alliance".  He concluded by saying "our long-term priorities remain unchanged. We are driving the performance of brands that retain exclusivity, investing in markets with long-term potential, reshaping the cost base for sustainable competitiveness and continuing to drive for productivity on our investments in innovation, whether internally or externally sourced".

Investors are not terribly impressed however and at 9.30am, AstraZeneca shares had fallen 1.8% to £28.56.