United States: IPR: A Key Tool in the Arsenal of Litigants and Non-Litigants Alike

Last Updated: May 3 2018
Article by RPX Corporation

Over the past five years, inter partes reviews (IPRs) have caused a dramatic shift in how patent disputes get resolved. Filing IPRs is a common first step for defendants faced with new litigation, allowing them to challenge patent validity early, without months of costly litigation, and thus potentially resolve cases more quickly. Now that the US Supreme Court has affirmed the review proceeding's constitutionality in Oil States Energy Services v. Greene's Energy Group, IPR's role as a key defensive tool appears set to solidify even further.

Unsurprisingly, IPR is an especially popular tool for companies that are regularly hit by patent infringement cases. To illustrate this, 88% of petitions are filed by defendants against whom those patents were previously asserted, and the top four IPR filers by number of petitions, each a frequent defendant, account for 12% of the petitions filed through March 31, 2018. For such companies, IPR has become a practical necessity, due to the benefits of challenging validity early in the course of litigation and thus providing greater leverage with respect to settlement. Given that such IPR filings are borne out of necessity, however, defendants are not able to be as selective with regard to the patents they target for IPR. In initiating IPR filings, they must generally target all asserted patents, rather than focusing only on those patents that are most vulnerable to a validity challenge.

Companies that do not regularly find themselves the targets of patent infringement cases ("non-litigants"), in contrast, are able to file petitions without the strategic constraints imposed by litigation. For example, RPX uses IPR as a cost-effective way to address irrational price expectations in the patent market and encourage greater market-wide rationality.

IPR Success Rates and the Importance of Merits-Based Analysis

In February 2017, RPX released a first-of-its kind study addressing the merits-based success rates of top petitioners for IPR. Since the release of that study, analyzing merits-based decisions at the PTAB has become all the more essential: in the wake of the Federal Circuit's 2016 ruling in Shaw Industries Group v. Automated Creel Systems, which established that estoppel does not apply for grounds not instituted, more district courts have applied § 315(e)(2) estoppel as a function of whether a prior PTAB decision was based on the merits. The importance of focusing on such outcomes has been further underscored by the PTAB's ensuing precedential and informative decisions,* which have arguably provided panels with more discretion to deny institution of a petition on the basis of previous merits-based consideration of prior art in the petition. With that in mind, the study below provides updated data on merits-based success rates of top filers.

As of March 31, 2018, RPX data indicate that petitioners receive favorable institution decisions on the merits 75% of the time—a decline of around 3% from December 31, 2016. The institution decision success rates of the top litigants decreased over that same period by an amount comparable to the drop in the industry average. However, over the same time period, the institution decision success rates of the top four non-litigant IPR filers have increased by 6%, departing from the industry average, likely because non-litigant filers have had the luxury of developing and implementing more sophisticated filing criteria being unburdened by the aforementioned strategic constraints.

IPR Institution Decision Success Rates

In addition, RPX data show that as of March 31, 2018, IPRs cancel at least one claim 83% of the time at the final decision stage. This high petitioner success rate is largely because institution decisions, by their very nature, weed out the asserted grounds for invalidity that are unlikely to succeed. As a result, most of the top litigant IPR filers were within 3% of the industry average success rate for final decisions, with Apple's success rate reaching 93%. RPX, meanwhile, has enjoyed a success rate of 94%.

IPR Final Decision Success Rates

The Road Ahead

While IPR has already become an essential tool for litigants in particular, its popularity among defendants could further increase in the months ahead should other means for bringing early validity challenges become less readily available: for example, if district courts become less inclined to grant early Alice motions due to the Federal Circuit's decisions in Berkheimer v. HP and Aatrix Software v. Green Shades Software. IPR filing levels are likely to increase now that the Supreme Court has upheld IPR's constitutionality in Oil States.

However, the Court has also rejected the PTAB's practice of issuing partial institution decisions in Oil States's companion case, SAS Institute v. Iancu, which has the potential to significantly alter the strategic considerations for some litigant petitioners. This is partly due to estoppel, which in this context means that an IPR petitioner is barred from raising any invalidity arguments in a district court lawsuit that the petitioner "raised or reasonably could have raised during" an IPR. Petitioners may need to reconsider which claims they target in a petition in view of potentially broader estoppel attaching to final written decisions. For example, targeting claims beyond those at issue in a district court infringement case and getting an adverse final written decision may create opportunities for downstream patent owners asserting different claims and/or other patents within the same families. Nonetheless, SAS Institute may benefit defendants if it leads courts to more readily grant stays in litigation.

Finally, the past year has seen a number of arguably patent-owner-friendly changes to the IPR regime, including the PTAB's imposition of a more stringent threshold for follow-on petitions in General Plastic Industrial v. Canon, and the Federal Circuit's decision in Aqua Products v. Matal, which essentially shifted the burden of proof for the unpatentability of amended claims to the IPR petitioner.

Despite the potential impact of such changes, IPRs remain a popular tool for both litigants and non-litigants alike, and they serve as a key part of a holistic strategy for reducing patent risk.


  1. The study covers petitions filed through March 31, 2018 and final decisions through March 31, 2018. Institution decisions are not counted for petitions with filing dates that are still within the six-month pre-trial window to avoid bias against those petitions for which an institution decision remains pending. All decisions were manually coded and verified.
  2. Only merits-based decisions were counted. Examples of excluded non-merits-based decisions include discretionary denials (e.g., 35 USC § 325(d); General Plastic Industrial Co., Ltd. v. Canon Kabushiki Kaisha (IPR2016-01357); NVIDIA Corp. v. Samsung Elec. Co. (IPR2016-00134)); denials of institution under 35 USC § 315(b); denials of institution under 35 USC § 311(b) based on the Board finding that the petitioner failed to qualify an alleged prior art reference as prior art; and denials pursuant to the patent owner having filed, before a decision on institution, a statutory disclaimer thus disclaiming all or some of the petitioned claims. Adverse judgments and joinders were counted as merits-based decisions where applicable: adverse judgments because of the related estoppel provisions, and joinders because joining parties often contributed to arguments and prosecution of the IPRs.
  3. Institution decisions and final decisions are considered successful if at least one claim challenged in the petition is instituted or cancelled, respectively.
  4. Because of estoppel provisions, adverse judgments granted against the patent owner prior to institution are counted as both successful institution decisions and successful final outcomes, and adverse judgment against patent owner post institution, are counted as successful final outcomes.

*See General Plastic Industrial Co., Ltd. v. Canon Kabushiki Kaisha (IPR2016-01357); Cultec, Inc. v. Stormtech LLC (IPR2017-00777); Hospira, Inc. v. Genentech, Inc. (IPR2017-00739); Unified Patents, Inc. v. Berman (IPR2016-01571); Kayak Software Corp. et al. v. International Business Machines Corp. (CBM2016-00075); and Becton Dickinson & Co. v. B. Braun Melsungen AG (IPR2017-01586).

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.

To print this article, all you need is to be registered on Mondaq.com.

Click to Login as an existing user or Register so you can print this article.

In association with
Related Topics
Related Articles
Related Video
Up-coming Events Search
Font Size:
Mondaq on Twitter
Register for Access and our Free Biweekly Alert for
This service is completely free. Access 250,000 archived articles from 100+ countries and get a personalised email twice a week covering developments (and yes, our lawyers like to think you’ve read our Disclaimer).
Email Address
Company Name
Confirm Password
Mondaq Topics -- Select your Interests
 Law Performance
 Law Practice
 Media & IT
 Real Estate
 Wealth Mgt
Asia Pacific
European Union
Latin America
Middle East
United States
Worldwide Updates
Registration (you must scroll down to set your data preferences)

Mondaq Ltd requires you to register and provide information that personally identifies you, including your content preferences, for three primary purposes (full details of Mondaq’s use of your personal data can be found in our Privacy and Cookies Notice):

  • To allow you to personalize the Mondaq websites you are visiting to show content ("Content") relevant to your interests.
  • To enable features such as password reminder, news alerts, email a colleague, and linking from Mondaq (and its affiliate sites) to your website.
  • To produce demographic feedback for our content providers ("Contributors") who contribute Content for free for your use.

Mondaq hopes that our registered users will support us in maintaining our free to view business model by consenting to our use of your personal data as described below.

Mondaq has a "free to view" business model. Our services are paid for by Contributors in exchange for Mondaq providing them with access to information about who accesses their content. Once personal data is transferred to our Contributors they become a data controller of this personal data. They use it to measure the response that their articles are receiving, as a form of market research. They may also use it to provide Mondaq users with information about their products and services.

Details of each Contributor to which your personal data will be transferred is clearly stated within the Content that you access. For full details of how this Contributor will use your personal data, you should review the Contributor’s own Privacy Notice.

Please indicate your preference below:

Yes, I am happy to support Mondaq in maintaining its free to view business model by agreeing to allow Mondaq to share my personal data with Contributors whose Content I access
No, I do not want Mondaq to share my personal data with Contributors

Also please let us know whether you are happy to receive communications promoting products and services offered by Mondaq:

Yes, I am happy to received promotional communications from Mondaq
No, please do not send me promotional communications from Mondaq
Terms & Conditions

Mondaq.com (the Website) is owned and managed by Mondaq Ltd (Mondaq). Mondaq grants you a non-exclusive, revocable licence to access the Website and associated services, such as the Mondaq News Alerts (Services), subject to and in consideration of your compliance with the following terms and conditions of use (Terms). Your use of the Website and/or Services constitutes your agreement to the Terms. Mondaq may terminate your use of the Website and Services if you are in breach of these Terms or if Mondaq decides to terminate the licence granted hereunder for any reason whatsoever.

Use of www.mondaq.com

To Use Mondaq.com you must be: eighteen (18) years old or over; legally capable of entering into binding contracts; and not in any way prohibited by the applicable law to enter into these Terms in the jurisdiction which you are currently located.

You may use the Website as an unregistered user, however, you are required to register as a user if you wish to read the full text of the Content or to receive the Services.

You may not modify, publish, transmit, transfer or sell, reproduce, create derivative works from, distribute, perform, link, display, or in any way exploit any of the Content, in whole or in part, except as expressly permitted in these Terms or with the prior written consent of Mondaq. You may not use electronic or other means to extract details or information from the Content. Nor shall you extract information about users or Contributors in order to offer them any services or products.

In your use of the Website and/or Services you shall: comply with all applicable laws, regulations, directives and legislations which apply to your Use of the Website and/or Services in whatever country you are physically located including without limitation any and all consumer law, export control laws and regulations; provide to us true, correct and accurate information and promptly inform us in the event that any information that you have provided to us changes or becomes inaccurate; notify Mondaq immediately of any circumstances where you have reason to believe that any Intellectual Property Rights or any other rights of any third party may have been infringed; co-operate with reasonable security or other checks or requests for information made by Mondaq from time to time; and at all times be fully liable for the breach of any of these Terms by a third party using your login details to access the Website and/or Services

however, you shall not: do anything likely to impair, interfere with or damage or cause harm or distress to any persons, or the network; do anything that will infringe any Intellectual Property Rights or other rights of Mondaq or any third party; or use the Website, Services and/or Content otherwise than in accordance with these Terms; use any trade marks or service marks of Mondaq or the Contributors, or do anything which may be seen to take unfair advantage of the reputation and goodwill of Mondaq or the Contributors, or the Website, Services and/or Content.

Mondaq reserves the right, in its sole discretion, to take any action that it deems necessary and appropriate in the event it considers that there is a breach or threatened breach of the Terms.

Mondaq’s Rights and Obligations

Unless otherwise expressly set out to the contrary, nothing in these Terms shall serve to transfer from Mondaq to you, any Intellectual Property Rights owned by and/or licensed to Mondaq and all rights, title and interest in and to such Intellectual Property Rights will remain exclusively with Mondaq and/or its licensors.

Mondaq shall use its reasonable endeavours to make the Website and Services available to you at all times, but we cannot guarantee an uninterrupted and fault free service.

Mondaq reserves the right to make changes to the services and/or the Website or part thereof, from time to time, and we may add, remove, modify and/or vary any elements of features and functionalities of the Website or the services.

Mondaq also reserves the right from time to time to monitor your Use of the Website and/or services.


The Content is general information only. It is not intended to constitute legal advice or seek to be the complete and comprehensive statement of the law, nor is it intended to address your specific requirements or provide advice on which reliance should be placed. Mondaq and/or its Contributors and other suppliers make no representations about the suitability of the information contained in the Content for any purpose. All Content provided "as is" without warranty of any kind. Mondaq and/or its Contributors and other suppliers hereby exclude and disclaim all representations, warranties or guarantees with regard to the Content, including all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement. To the maximum extent permitted by law, Mondaq expressly excludes all representations, warranties, obligations, and liabilities arising out of or in connection with all Content. In no event shall Mondaq and/or its respective suppliers be liable for any special, indirect or consequential damages or any damages whatsoever resulting from loss of use, data or profits, whether in an action of contract, negligence or other tortious action, arising out of or in connection with the use of the Content or performance of Mondaq’s Services.


Mondaq may alter or amend these Terms by amending them on the Website. By continuing to Use the Services and/or the Website after such amendment, you will be deemed to have accepted any amendment to these Terms.

These Terms shall be governed by and construed in accordance with the laws of England and Wales and you irrevocably submit to the exclusive jurisdiction of the courts of England and Wales to settle any dispute which may arise out of or in connection with these Terms. If you live outside the United Kingdom, English law shall apply only to the extent that English law shall not deprive you of any legal protection accorded in accordance with the law of the place where you are habitually resident ("Local Law"). In the event English law deprives you of any legal protection which is accorded to you under Local Law, then these terms shall be governed by Local Law and any dispute or claim arising out of or in connection with these Terms shall be subject to the non-exclusive jurisdiction of the courts where you are habitually resident.

You may print and keep a copy of these Terms, which form the entire agreement between you and Mondaq and supersede any other communications or advertising in respect of the Service and/or the Website.

No delay in exercising or non-exercise by you and/or Mondaq of any of its rights under or in connection with these Terms shall operate as a waiver or release of each of your or Mondaq’s right. Rather, any such waiver or release must be specifically granted in writing signed by the party granting it.

If any part of these Terms is held unenforceable, that part shall be enforced to the maximum extent permissible so as to give effect to the intent of the parties, and the Terms shall continue in full force and effect.

Mondaq shall not incur any liability to you on account of any loss or damage resulting from any delay or failure to perform all or any part of these Terms if such delay or failure is caused, in whole or in part, by events, occurrences, or causes beyond the control of Mondaq. Such events, occurrences or causes will include, without limitation, acts of God, strikes, lockouts, server and network failure, riots, acts of war, earthquakes, fire and explosions.

By clicking Register you state you have read and agree to our Terms and Conditions