Court denies Novo Nordisk injunction against Exubera

Pfizer has revealed that the US District Court for the southern district of New York has denied a motion for a preliminary injunction, which would have blocked further US sales of its inhalable insulin product, Exubera.

The preliminary injunction was requested by Novo Nordisk as part of an alleged patent infringement case which will be heard by the same court.

Exubera is the only inhalable form of insulin to be approved by the FDA. Pfizer developed the product with US drug delivery company, Nektar, which also developed the inhaler device to deliver the powdered insulin. The court's decision allows the product to remain on the US market and available to patients while the case proceeds to trial.

Novo Nordisk, which is the leading supplier of insulin, initiated the court action back in August 2006. The Danish drug company claimed that Exubera violated five of its insulin patents, the first of which was filed in 1993. The company is currently conducting phase III tests with AERx, a form of inhaled insulin that uses an aerosol. Novo Nordisk developed the product with US drug delivery firm, Aradigm. If successful, Novo Nordisk's study, which involves 2,000 patients, should see AERx file with the FDA in 2009.

In November 2006, media reports said that the US Patent Office rejected Novo Nordisk's patent application for AERx because ìit did not contribute anything new to the fieldî. Novo Nordisk refuted this, accusing the Patent Office of ìmisinterpreting data, evidence and legislationî, vowing to fight the decision.

Inhaled insulin devices have been a hot topic in 2006, with the Exubera launch. Eli Lilly's AIR Insulin system is also another contender for the new market. AERx is the only inhaled insulin device in clinical trials using a liquid formulation that requires refrigeration.

According to an October 2006 Datamonitor report, although the new formulation of the drug would remove the need for injections, patients would still have to put up with the usual disadvantages of insulin therapy, including weight gain and the need to adhere to a restrictive meal-dependent administration routine.

Datamonitor forecasts sales of Exubera to fall well short of previous estimates and stabilise at $207 million (£106 million) by 2015, and predicts that once launched, US biopharmaceutical company, Mannkind, would generate $288 million (£147 million) in revenue from its dry power insulin product, Technosphere, by that time, at the expense of its other three competitors.