Applied Health Economics and Health Policy

, Volume 17, Issue 1, pp 47–54 | Cite as

The Generic Drug Industry Embraces a Faster, Cheaper Pathway for Challenging Patents

  • Jonathan J. DarrowEmail author
  • Reed F. Beall
  • Aaron S. Kesselheim
Original Research Article



Most new brand-name drugs are protected by patents from generic competition, but these patents are occasionally granted in error. Invalidating such patents has traditionally been accomplished via court litigation by generic manufacturers, which is expensive and time consuming. In 2011, Congress created an administrative alternative to court litigation of patents, called inter partes review, intended to be much faster and less expensive.


To evaluate the use of inter partes review to challenge pharmaceutical patents, including the number of challenges, the number of associated drug products, and the extent to which challengers have been successful.


We obtained data pertaining to inter partes review proceedings, including identity of patent challenger, duration of proceedings, and outcome, from September 16, 2012 through April 24, 2017 from, and combined it with information about drug products and their associated patents, including patent type, contained in the US Food and Drug Administration’s Orange Book.


Generic drug manufacturers have embraced the new inter partes review process, succeeding in overturning all challenged claims in 43% of the patents they have targeted since 2011, and some challenged claims in an additional 8%. Inter partes review for drug patents has consistently been completed within 12 months, as required by statute. Successful challenges have been brought most frequently against drug patents covering new formulations or methods of use, rather than drug patents covering active ingredients.


In the pharmaceutical market, the inter partes review process can meaningfully contribute to ensuring that invalid patents do not block timely availability of generic drugs.



The authors thank Frazer Tessema, Adrian J. Santiago Ortiz, and Kristina Stefanini for their assistance with the research.

Data Availability Statement

Publicly-available key data are presented in an Online Supplement table. Some additional data that support the findings of this study are available from but restrictions apply to the availability of these data, which were used with permission for the current study. Similar data regarding inter partes review proceedings can be found at

Author Contributions

Conception: ASK, JJD. Design: JJD, RFB. Collection and analysis of data: JJD, RFB. Drafting of the manuscript: JJD. Revision of the manuscript: all authors. Financial support: ASK. Final approval of the manuscript: all authors.

Compliance with Ethical Standards

Work on this project at the Program on Regulation, Therapeutics, and Law (PORTAL) was supported by the Laura and John Arnold Foundation, as well as the Harvard Program in Therapeutic Science and the Engelberg Foundation.

Conflict of interest

JJD, RFB, and ASK report no conflicts of interest.


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Copyright information

© Springer Nature Switzerland AG 2018

Authors and Affiliations

  1. 1.Program On Regulation, Therapeutics, And Law (PORTAL), Division of Pharmacoepidemiology and Pharmacoeconomics, Department of MedicineBrigham and Women’s Hospital and Harvard Medical SchoolBostonUSA

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