Written Description: Single Embodiment Insufficient

This decision is nothing new. Broad claims must either be supported by multiple embodiments or some general principles describing how the single embodiment is applicable to other configurations. Failing that, a broad claim may fail the enablement prong. As seen here, even when enabled, a broad claim without sufficient support will be invalid under the written description requirement.

In re Alonso (Fed. Cir. 2008)

The PTO Board of Appeals (BPAI) rejected claim 92 of Kenneth Alonso’s for failing the written description requirement of Section 112. “To satisfy this requirement, the specification must describe the invention in sufficient detail so that one skilled in the art can clearly conclude that the inventor invented the claimed invention as of the filing date sought.” (quoting case). In an opinion written by Judge Stearns (D.M.A.) sitting by designation, the Federal Circuit affirmed.

Claim 92 of the Alonso patent application claims a “method of treating neurofibrosarcoma in a human by administering an effective amount” of an idiotypic monoclonal antibody (mAb) secreted in a human-human cell hybridoma.

In his application, Alonso only described the preparation of a single mAb, but claimed essentially all Mab’s that bind to neurofibrosarcoma, and the PTO found that a “skilled artisan would reasonably conclude that applicant was clearly not in possession of the claimed genus of compounds. Applicant should direct the claim language toward the only described embodiment (e.g., a mAb produced by hybridoma HB983).”

Standard of Review: The PTO’s factual determinations are reviewed for “substantial evidence.” Thus, the Federal Circuit will affirm when “a reasonable mind might accept [the evidence] as adequate to support a conclusion.” Even if the Federal Circuit might ultimately have seen the facts differently, it will affirm if the PTO’s position is reasonable.

Predictability: The Federal Circuit acknowledged that disclosure of a single embodiment can be sufficient for a broader genus claim. However, more disclosure is necessary when the composition and effectiveness of members of the genus is heterogeneous or unpredictable.

We have previously held in a similar context that “a patentee of a biotechnological invention cannot necessarily claim a genus after only describing a limited number of species because there may be unpredictability in the results obtained from species other than those specifically enumerated.” Noelle v. Lederman, 355 F.3d 1343, 1350 (Fed. Cir. 2004).

Alonso argued that his single embodiment should be given more weight because he had actually reduced it to practice (unlike the Rochester COX-2 case). The Federal Circuit rejected that argument because Alonso had not provided the necessary predictive information – “nothing about the structure, epitope characterization, binding affinity, specificity, or pharmacological properties common to the large family of antibodies implicated by the method.”


  • The court gives the following justification for the written description requirement: “The requirement ‘serves a teaching function, as a quid pro quo in which the public is given meaningful disclosure in exchange for being excluded from practicing the invention for a limited period of time.'” quoting Univ. of Rochester, 358 F.3d 916 (Fed. Cir. 2004) (in turn quoting Enzo Biochem, 323 F.3d 956 (Fed. Cir. 2002)).
  • In his 2005 book on Electronic and Software Patents, Steve Lundberg, et al. include the understatement: “The purpose of the written description requirement has been in flux recently.”

11 thoughts on “Written Description: Single Embodiment Insufficient

  1. 11

    I agree with some other posters here that a fair scope of protection, proportionate of course to the contribution of the inventor to the art is what really matters here. Really, why is that so difficult to understand? What is the argument to the contrary?

  2. 10

    Ms. Culpability:

    Do you prefer bright-line rules? What if one example is perfectly sufficient? Should that applicant fail because of an arbitrary number limit despite an otherwise descriptive disclosure?

  3. 9

    CS – Thanks for disabusing me – you are correct that I did not read the opinion.

    Malcolm – work on your darn summaries for lazy guys like me!

    Based on CS’s summary, however, this decision is a big DUH! Excuse the patentese.

  4. 8


    I suspect that you did not read this decision based on your comment. The issue was not whether, given an antigen, multiple different antibodies were obvious. The issue was whether, given a cell, demonstrated by the Examiner to be heterogenous, with multiple different undisclosed antigens. The Board cited an article by the inventor himself, who said that “A[t]he efficacy of antibody therapy is thought to be related to tumor burden as well as to idiotypic change in the original tumor.” So the inventor recognized that unique antigens may exist only on tumors in a single patient.

    It is in that context that one example was found to be insufficient.

    Examiners routinely allow claims like “antibodes to SEQ ID NO:X” if the sequence is new, even if no examples are given, since everyone recognizes that with a known antigen, antibody generation is trivial. The problem that GP failed to appreciate in Alonzo is that the antigens themselves were not disclosed by any means whatsoever.

  5. 7

    page 10: “functional characteristics when coupled with a known or disclosed correlation between function and structure, or some combination of such characteristics.”

    If Alonso raised this argument in BAPI, the result might tbe different.

  6. 6

    “In his 2005 book on Electronic and Software Patents, Steve Lundberg, et al. include the understatement: “The purpose of the written description requirement has been in flux recently.”

    It’s been a reliable method of limiting biotech claims to disclosed embodiments for quite some time.

    I don’t recall ever seeing it applied to a software patent, e.g., limiting a software claim to one reciting a specific bit of source code.

    Perhaps this is because most software patents don’t include *any* working examples of the software.

  7. 5

    Ah, now you point it out Hercules, I guess you’re right. What’s your take on GP? Doesn’t the court deal with that point, when it discusses “predictability”?

  8. 3

    Unbelievable? Not to an oldster. It’s all about the generations old public policy objective of awarding a fair scope of protection, proportionate to the inventor’s contribution to the art. Common sense really.

  9. 2

    More confusion in WD? How surprising.

    What may have been useful would have been the court indicating HOW MANY working examples would have been sufficient.

    Typical useless case law, except to the extent that ONE example is now too few, with regard to monoclonal antibodies.

    Give me the antigen the lab and enough time and I’ll be happy to give you a hundred monoclonal antibodies specific to the antibody.

    You want 1,000? OK, we can do that too.

    More useless case law on top of useless case law.

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