Inhaled Insulin: Troubled Drug Rises from the Ashes

The Hospitalist. 2009 January;2009(01):

January 1, 2009|The Hospitalist

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

Market watch

New Indications and Dosage Forms

Immune Globulin (Gamunex, Talecris Biotherapeutics Inc.) has received orphan drug status for treating chronic inflammatory demyelinating polyneuropathy (CIPD), a rare autoimmune disorder characterized by progressive weakness and impaired sensory function in the extremities, which affects approximately 25,000 people in the U.S. CIPD leads to weakness, loss of deep tendon reflexes, tingling, and numbness from myelin sheath damage. Gamunex is manufactured from pooled human plasma. Its mechanism is unknown, but it is thought to work by modulating the immune system’s inflammatory response, which damages the myelin sheaths.8
Levetiracetam extended-release (Kep-pra XR, UCB Pharma) has been FDA-approved as once-daily, add-on therapy to other antiepileptic agents for patients 16 years of age and older with partial onset seizures.9

New Warnings

The FDA and Genentech informed healthcare professionals of a labeling revision for rituximab (Rituxan). It is related to an additional case and subsequent death from progressive multifocal leukoencephalopathy (PML) in a rheumatoid arthritis patient. The patient developed PML 18 months after the final rituximab dose. The patient was immunologically unstable from cancer chemotherapy, and had received prior biologic agents, which may have contributed to the poor immunologic state. Healthcare professionals need to be aware of the possibility of PML when treating patients with rituximab. Consider it in the differential diagnosis of patients presenting with new onset neurologic manifestations. A neurologist and subsequent testing should be considered as clinically indicated.10

New Information

Pregnancy Categories. Women take, on average, between three to five prescription drugs during pregnancy, with about 6 million U.S. pregnancies each year. In the 1990s, the FDA began recognizing deficiencies in pregnancy and breastfeeding information in prescription drug labeling.

The FDA has proposed a change to the way prescription labels present this information. If approved, this new measure would remove the current letter categories (e.g., A, B, C, D, X) and utilize language to detail fetal risk, clinical considerations, and supporting data. If enacted, it would be formatted into three sections. Whether a pregnancy exposure registry is available also would be included in the new labeling. The lactation section would follow the same format; it would include information on the amount of drug in breast milk and potential effects on the breastfed infant.

Newly approved drugs would follow the new pregnancy category structure, yet older drugs would be phased in gradually.11,12,13

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