The days seem to be numbered for inhaled insulin after Pfizer updated the labelling on its no-longer marketed Exubera product to include a warning relating to lung cancer.

The New York-based drugs giant updated the Exubera label as part of an ongoing review of clinical data and post-marketing reports. The firm found that six of 4,740 Exubera patients compared with one of 4,292 patients not using the inhaler developed lung cancer and another case was discovered after the drug was launched.

Pfizer noted that all of the cases related cigarette smokers and there were too few cases to determine whether the development of lung cancer was related to its product. Chief medical officer Joe Feczko said that some people continue to take the product, including those enrolled in extended transition programmes or clinical trials and the firm is working closely with patients and their physicians “to ensure the continued orderly transition from Exubera to alternative therapies”.

The warning is the latest bit of bad news for inhaled insulin since Pfizer finally gave up on Exubera in October last year, having acquired co-marketing rights to the drug from partner Sanofi-Aventis for $1.3 billion in January 2006. It was launched in the middle of 2006 but failed to make any sort of mark.

A dispute with Nektar Therapeutics, which accused Pfizer of not marketing Exubera properly, was settled, helped by a one-time $135 million payment. However, it appears that Nektar has also given up hope.

Nektar giving up inhaled insulin talks
The latter issued a statement saying that it has “ceased all negotiations with potential partners for its inhaled insulin programmes” as a result of Pfizer’s new data analysis. Chief executive Howard Robin also noted that “fortunately, over the past year, Nektar has significantly transformed its business, moving away from inhaled insulin”. It has ceased all spending associated with its inhaled insulin programmes, though the news went down badly with investors and Nektar stock sank 25%.

Just last month, Eli Lilly ended its Phase III AIR inhaled insulin programme for type 1 and type 2 diabetes, which was being developed with Alkermes, while Novo Nordisk also recently announced that it was halting development of its AERx inhaled insulin product, a move which resulted in a $260 million charge.

That leaves the USA’s MannKind Corp as the solitary flag-bearer for inhaled insulin products. Last month, the firm said it was “absolutely committed” to the continued development of its Technosphere Insulin programme, which is in Phase III trials, but the latest news about Exubera has left the whole concept of inhaled insulin battered and bruised. Mannkind’s shares ended the day down a massive 59.8% at $2.35.