Big pharma may think that this year looks horrendous in terms of exposure to generics but 2012 is going to be twice as bad.

That's the conclusion of an analysis from research group EvaluatePharma's EP Vantage unit, which notes that while Pfizer’s cholesterol blockbuster Lipitor (atorvastatin) and Eli Lilly’s antipsychotic Zyprexa (olanzapine) lose market exclusivity this year, a "staggering $33.2 billion of sales will be exposed to generics in 2012 in the USA alone, more than double this year’s figure, representing "a true annus horribilis".

The analysis, which focuses on the USA, "where the impact of patent expiry can be seen most clearly", notes that certain developments in the past 12 months "mean the hit in 2011 has been dampened somewhat". These include Bristol-Myers Squibb and Sanofi-Aventis winning a six-month paediatric extension last month to blood thinner Plavix (clopidogrel) and the lack of any generic versions on the horizon of GlaxoSmithKline's asthma and chronic obstructive pulmonary disease combo Advair (salmeterol/fluticasone).

EP Vantage also notes the uncertainty that still surrounds the launch of copycat versions of Lipitor, the US patent for which expires in November. Ranbaxy will launch its version with 180 days exclusivity and Watson Pharmaceuticals will introduce an authorised generic at the same time.

However, the analysis claims that "there are question marks over Ranbaxy’s ability to launch given its manufacturing deficiencies", although its recent introduction of generic versions of the Pfizer/Eisai Alzheimer's disease drug Aricept (donepezil) "suggest these concerns may be subsiding". US sales of Lipitor  are set to be less than $150 million in 2013 will be less than $150 million.

It is not just Lipitor under threat and Pfizer has four of the 15 biggest patent expiries in the US in the next two years -  the antiulcerant Protonix (pantoprazole), Viagra (sildenafil) for erectile dysfunction and anti-psychotic Geodon (ziprazidone) will all face generic competition by the end of 2012. EP Vantage adds that this means "Pfizer's reign as the world's biggest drug maker will soon be over. Analysts expect Novartis to become the world's biggest seller of prescription and over-the-counter drugs next year, embarking on its own period of dominance".

The analysis concludes by noting that the rate of erosion of branded sales "is set to remain incredibly high until 2015" and "the big picture is one of painful losses to sales and earnings, the scale of which the industry has never seen before".