Patent Challenges And Litigation On Inhalers For Asthma And COPD

Health Aff (Millwood). 2023 Mar;42(3):398-406. doi: 10.1377/hlthaff.2022.00873.


Between 1986 and 2020 the Food and Drug Administration (FDA) approved fifty-three brand-name inhalers for asthma and chronic obstructive pulmonary disease (COPD), but by the end of 2022 only three of those inhalers faced independent generic competition. Manufacturers of brand-name inhalers have created long periods of market exclusivity by obtaining multiple patents, many on the delivery devices rather than the active ingredients, and by introducing new devices that contain old active ingredients. Limited generic competition for inhalers has raised questions about whether the Drug Price Competition and Patent Term Restoration Act of 1984, also known as the Hatch-Waxman Act, for challenging patents is adequately facilitating the entry of complex generic drug-device combinations. For the fifty-three brand-name inhalers approved during the period 1986-2020, generic manufacturers filed challenges authorized by the Hatch-Waxman Act, which are known as paragraph IV certifications, on only seven products (13 percent). The median time from FDA approval to first paragraph IV certification was fourteen years. Paragraph IV certifications resulted in approved generics for only two products, each of which experienced fifteen years of market exclusivity before generic approval. Reform of the generic drug approval system is critical to ensuring the timely availability of competitive markets for generic drug-device combinations such as inhalers.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Asthma* / drug therapy
  • Drug Approval
  • Drugs, Generic
  • Humans
  • Nebulizers and Vaporizers
  • Pulmonary Disease, Chronic Obstructive* / drug therapy
  • United States


  • Drugs, Generic