Remember all the hype leading up to the approval of the dry-powder formulation of human insulin, produced by means of recombinant DNA technology, a.k.a. inhaled insulin (Exubera)? That was three years ago (January 2006). Remember all the press releases regarding the removal of inhaled insulin from the market? That was October 2007.1,2
Almost immediately after Pfizer “pulled the plug” on inhaled insulin, cases of lung cancer started being reported—albeit it had occurred in Exubera-treated patients that had a history of smoking cigarettes—a contraindication within the drug’s approved label. Some clinicians questioned whether it was due to insulin being a weak growth factor when binding to the type 1 insulin-like growth factor receptor; others wondered if it was related to smoking history.3,4 Three other collaboration efforts for inhaled insulin—NovoNordisk/Aradigm, MannKind, and Alkermes/Eli Lilly AIR insulin— were in the pipeline when Pfizer bowed out of the market. MannKind’s Technosphere insulin and Alkermes/Eli Lilly AIR insulin are still being investigated. Both are in phase 3 clinical trials.5
So, contrary to popular belief, inhaled insulin is not dead, yet. These other companies are looking to improve upon what Pfizer lost out on. The AIR system uses a smaller, breathable inhaler, which would fit into a patient’s hand. The inhaled powder has a smaller particle size and a larger surface area, which provides deeper lung penetration of drug.6