United States: Federal Circuit Considers The "Newly Characterized Antibody" Test In Amgen V. Sanofi But Might Pass On A Ruling

The Federal Circuit posed difficult questions on the "newly characterized antigen" test (a.k.a., the antibody exception as provided in the USPTO Written Description Guidelines) to Sanofi (the appellant-defendants) during oral argument last week in Amgen v. Sanofi, a first opportunity for the Federal Circuit to squarely address the validity of this test. Amgen, Inc. v. Sanofi, No. 17-1480 (Fed. Cir. 2017). In contrast, the judges did not question Amgen on this point and gave little indication on whether they will rule on this issue. With four other issues before the court, including whether a new trial is required on written description and enablement, the court need not reach this issue to decide the case.

35 U.S.C. §112(a) requires that the specification of a patent provide "a written description of the invention and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention." 35 U.S.C. § 112(a) (2012 Current through P.L. 115-30) . In the biological arts, according to case law, written description of a genus may be met by describing "common structural features" among the members of the claimed genus or a "representative number of species." In addition, the USPTO Manual of Patent Examining Procedure provides a "newly characterized antigen" test, which carves out an exception allowing for written description support for a claim to a genus of antibodies through the disclosure of a newly characterized antigen, if the level of skill and knowledge at the time of filing was such that the production of such antibodies was conventional or routine. At trial, the district court held Amgen's antibody claims not invalid, relying, at least in part, on the "newly characterized antigen test," and issued a permanent injunction against Sanofi. MPEP § 2163 (II)(3)(a) ¶ 5 (9th ed. 2015) (quoting Centocor Ortho Biotech, Inc. v. Abbott Labs, 636 F.3d 1341 (Fed. Cir. 2011). On appeal before the Federal Circuit last week, Sanofi challenged the test's validity.

Amgen alleges that Sanofi and its partner Regeneron infringed Amgen's patents covering antibodies that help reduce LDL cholesterol levels. Amgen's patent claims disclose an epitope and certain species of a broader antibody genus. The claims cover antibodies that bind to a region of the protein PCSK9 and block PCSK9 from binding to LDL-Receptor protein on liver cells. LDLR sits on liver cell surfaces and captures LDL from the bloodstream. Ordinarily, an LDLR-LDL complex migrates inside liver cells, where LDL is destroyed and LDLR recycles back to the cell surface to capture another LDL molecule. However, when PCSK9 is present, it binds to LDLR along with LDL, and the entire complex is destroyed inside liver cells, including LDLR. Thus, PCSK9 prevents LDLR recycling and contributes to higher levels of cholesterol. Both parties developed antibodies that help reduce LDL cholesterol levels, which they commercialized in Amgen's product Repatha® and Sanofi's Praluent®. Sanofi's Praluent® faces a 12 year injunction if the Federal Circuit upholds the district court's injunction.

In their brief, Sanofi argued that the "newly characterized antigen" test has no basis in statute, science, precedent, or common sense. Sanofi contends that the test is not scientifically supported because the structure and sequence of the antigen tells nothing about the antibodies. They also argue that no binding Federal Circuit precedent supports the test.

Amgen's brief, on the other hand, counters that Noelle v. Lederman, 355 F.3d 1343 (Fed. Cir. 2004) is a controlling precedent that confirms the validity of the test. Amgen backstops that argument, arguing that any error by the court below on the application of the "newly characterized antigen" test was harmless because the disclosure of representative species supports Amgen's claims even without applying that test.

At the hearing, Judge Prost pushed back against Sanofi's proposition that Federal Circuit precedents on point were dicta, not binding law, stating she considers this position "a little troubling" when the district court relied on quotes from Federal Circuit opinions, some of which she wrote. Initially dodging the issue, Paul Clement of Kirkland & Ellis LLP argued on behalf of Sanofi that even if the test is valid law, Amgen fails to meet it because the test applies only when the generation of claimed antibodies is routine, but the antibodies that satisfy Amgen's functional claims are anything but routine, and Amgen's discovery of the sequence of the PCSK9 epitope did not make the "intensive," "arduous," "trial-and error process" of generating the claimed antibodies any easier. He went on to argue that the "newly characterized antigen" test is invalid in a post-Myriad world because the test allows something akin to claiming a natural compound. Judge Prost's questioning on this issue did not go further.

Later, the panel allowed Daryl L. Joseffer of King & Spalding LLP, arguing for Amgen, to present arguments on the "newly characterized antigen" test without interruption. Mr. Joseffer argued that Noelle establishes the antigen-antibody test as the rule of law and rejected Sanofi's arguments that Amgen's discovery of the epitope did not help even Amgen generate the claimed antibodies. Rather, he reasoned that discovery of the so-called "sweet spot," 15 amino acids on PCSK9 to which antigens can bind and block PCSK9 from binding with LDLR, facilitated routine techniques like conservative substitutions and CDR shuffling that led to more efficient and effective antibody discovery. This, he argued, is precisely the point of the "newly characterized antigen" test, and the ensuing patent protection makes Amgen's two-billion dollar investment in Repatha research worthwhile.

On rebuttal, Clement minimized Amgen's contribution to the "newly characterized antigen" by pointing out that Novartis had already disclosed twelve of the fifteen amino acids in PCSK9, and that Amgen only disclosed two, not twenty-four, representative species. This minimal contribution, he concluded, shows the antibody exception is "fundamentally misconceived," because such a small contribution should not allow Amgen to "corner the market" on a life-saving drug.

Last week's oral arguments leave it uncertain how or even whether the court will rule on the validity of the "newly characterized antigen" test. The court may agree with Sanofi that Amgen fails to satisfy the test (if such a "newly characterized antigen" test is valid), agree with the Amgen that its claims are not invalid on other grounds, or decide the case on one of the four other issues before the court. If, for example, the court grants Sanofi's appeal for a new trial on a post-priority-date evidentiary question that was also at issue, the court need not reach the issue of the test's validity.

Originally printed in AIPLA Biotech Buzz  in June 2017.

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.

Events from this Firm
16 Jan 2019, Conference, Washington, DC, United States

Finnegan partner Lionel Lavenue will present “The Technology Accelerates: IP Issues at the Cutting Edge” during the Embry-Riddle Aeronautical University Aviation Law & Insurance Symposium.

22 Jan 2019, Webinar, Washington, DC, United States

As part of Strafford Publications’ webinar series, Finnegan partners Shana Cyr and Mark Feldstein will provide essential updates on FDA practice and patent law relating to biologics and biosimilars.

27 Jan 2019, Other, Washington, DC, United States

Finnegan is a sponsor of the Association of Corporate Patent Counsel Winter Meeting. Finnegan partner Erika Arner will join the panel discussion “PTAB Review & Litigation.”

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