Pfizer withdrew its diabetes drug Exubera last October because of lagging sales. At the time the decision seemed strange. The drug, an inhaled form of insulin, was reckoned to be Pfizer's next blockbuster, and investors were anticipating annual sales of around $2bn.
Its sudden withdrawal cost the company lb1.36bn ($2.8bn), made up of $661m of stock, $1.1bn of intangible assets, $454m of fixed assets and $584m of other costs. The drug had cost $900m to research and develop.
At the time Pfizer's chief medical officer Joseph Feczko said the withdrawal had nothing to do with safety issues - a surprising statement to make as, in April, the company revealed the drug dramatically increased the chances of lung cancer.
In clinical trials carried out by the company, six of the 4,740 patients taking Exubera developed lung cancer compared to just one out of 4,292 people who were not taking the drug. After the trial finished, another Exubera patient also developed lung cancer.
(Source: FDA website)