The product, which is being developed alongside drug delivery company Nektar Therapeutics, has been under review at the European Medicines Agency (EMEA) since February 2004, and could be on the market by the end of the year.
Exubera has had a troubled route through registration because despite its obvious appeal as an alternative to injections, because some data have suggested that it may be associated with a decline in lung function over time. And as diabetes requires chronic dosing with insulin, the concern is that patients taking the drug in this way could have complications later on.
In the wake of these data, Pfizer and Sanofi-Aventis delayed their marketing applications for the drug from the original schedule of 2001 in order to collate as much information as possible on Exubera's log term safety. Last September, the companies presented data suggesting that diabetics taking the drug exhibited no decline in lung function after two years.
If approved, Exubera will allow the firms to tap into a rapidly-expanding market, thus providing a significant commercial opportunity. Current estimates put the number of people with diabetes worldwide at nearly 180 million, a number which is expected to jump to 300 million in the next 20 years, according to the groups.
Another inhaled insulin drug from Alkermes and Eli Lilly is scheduled to start Phase III testing later this year, while other players in the sector include Novo Nordisk and Aradigm (Phase III) and MannKind (Phase II). Analysts have predicted that the first inhaled insulin product to reach the market could achieve sales upwards of $1.5 billion (€1.2bn) a year.