Biogen v. Glaxosmithkline: Prosecution History Disclaimer and Claim Construction

By Jason Rantanen

Biogen Idec, Inc. v. Glxosmithkline (Fed. Cir. 2013) Download Biogen v GSK
Panel: Dyk, Plager (dissenting), Reyna (author)

By the mid-1990's, it was well known that rituximab, an anti-CD20 antibody, could be used to treat certain cancers of the lymph nodes such as non-Hodgkins lymphoma.  The anti-CD20 antibody binds to a portion of the CD20 antigen protein exposed on the cell surface and destroys the cell.  Scientists from Biogen discovered that patients with another type of cancer, Chronic Lymphocytic Leukemia (CLL), could also be treated using anti-CD20 antibodies.  Based on this discovery, Biogen obtained Patent No. 7,682,612.  Claim 1 of the '612 patent reads:

1. A method of treating chronic lymphocytic leukemia in a human patient, comprising administering an anti-CD20 antibody to the patient in an amount effective to treat the chronic lymphocytic leukemia, wherein the method does not include treatment with a radiolabeled anti-CD20 antibody.

Biogen filed the application leading to the '612 patent in the late 1990s.  At the time, scientists believed that only one large loop, or epitope, of the CD20 antigen was exposed on the cancerous cell's surface and that this was the only site that for an anti-CD20 antigen to bind to.  Rituximab binds to this epitope. After Biogen filed its application, other scientists discovered that the CD20 antigen had a second small loop (originally thought to be hidden inside the cell) to which other, different anti-CD20 antibodies could bind.  In 2002, Glaxosmithkline (GSK) developed a new anti-CD20 antigen that binds to the small loop.  Because it binds to a different epitope, GSK's anti-CD20 antibody has different specificity and affinity characteristics than rituximab. 

Biogen sued GSK for infringement of the '612 patent in 2010.  The district court construed anti-CD20 antibody to mean "rituximab and antibodies that bind to the same epitope of the CD20 antigen with similar affinity and specificity as rituximab."  Based on this construction, Biogen stiplated to noninfringement and appealed. 

Prosecution History Disclaimer: The issue on appeal involved the the doctrine of prosecution history disclaimer.  Prosecution history disclaimer applies when a "patentee unequivocally and unambiguously disavows a certain meaning to obtain a patent."  Slip Op. at 8.  In this circumstance, the doctrine "narrows the meaning of the claim consistent with the scope of the claim being surrendered," id. overcoming even the term's ordinary and customary meaning.  Application of the doctrine helps serve a public notice function by allowing the public and competitors rely on definitive statements made during prosecution when launching a new product or designing-around a patented invention.

During an early stage of the prosecution of the '612 patent, the examiner rejected the presented claims on enablement grounds:

Claims 1 and 12 are broadly drawn to ‘. . . an anti-CD20 antibody or fragment thereof’. This is
broadly interpreted for examination purposes to be any and all anti-CD20 antibodies, no matter
the specificity or affinity for the specific epitope on the circulating tumor cells. While the specification is enabling for the application of RITUXAN®, RITUXIMAB® and 2B8-MX-DTPA in the treatment of hematologic malignancies, the specification is not enabling in the application of all other anti-CD20 antibodies, which may have different structural and functional properties.

In response, the applicant wrote:

Applicants respectfully submit that even though antibodies directed to the same antigen might have different affinities and functional characteristics, one of skill in the art could readily identify an antibody that binds to CD20 with similar affinity and specificity as does RITUXAN® using techniques that are well known in the art. . . . With that knowledge in hand, the skilled artisan could readily produce anti-CD20 antibodies using similar techniques, and screen such antibodies for those having an affinity and functional activity similar to Rituxan®

Based on this exchange in the context of the prosecution history read as a whole, the majority agreed with the district court that prosecution disclaimer applied to limit the scope of "anti-CD20 antibody."  "[R]ather than challenging the examiner’s understanding of the crucial terms, the applicants argued that the specification was enabling for anti-CD20 antibodies with similar affinity and specificity as Rituxan®."  Slip Op. at 10.  Nor was exact recitation of the examiner's own words necessary: "While disavowing statements must be “so clear as to show reasonable clarity and deliberateness,” Omega, 334 F.3d at 1325, this requirement does not require the applicant to parrot back language used by the examiner when clearly and deliberately responding to a particular grounds for rejection. If an applicant chooses, she can challenge an examiner’s characterization in order to avoid any chance for disclaimer, but the applicants in this case did not directly challenge the examiner’s characterization."  Slip Op. at 11. 

Hierarchy of canons of claim construction: In the hierarchy of canons of claim construction, prosecution history disclaimer trumps the presumption of claim differentiation: "Our cases make clear [] that where found, prosecution history disclaimer can overcome the presumption of claim differentiation."  Id. at 12 (note that the court said "can overcome," leaving open a door for cirucumstances in which it might not). 

Dissent: Writing in dissent, Judge Plager disagreed that this was an instance of prosecution history disclaimer.  "[T]he give-and-take that is often part of the process of negotiation between an examiner and an applicant may result in less-than-clear understandings, as happened here. Making too much of such ambiguous statements 'does not advance the patent’s notice function or justify public reliance.'"  Slip Op. at 16.  For Judge Plager, the question is thus "whether the prosecution history makes it clear that using RITUXAN® [Biogen's branded version of rituximab]-like antibodies is the only way to practice the claimed invention, and that no other antibodies can be used."  Id.  In his view, the above quoted statements fail to meet the "clear and unmistakable" standard required for prosecution history estoppel.  

The avoided question: By affirming the district court's claim construction, the CAFC avoided a battle over an extremely challenging issue: enablement in the context of after arising technologies and knowledge.  Biogen's proposed construction was "an antibody that binds to a cell surface CD20 antigen."  This construction would presumably encompass methods using antibodies that bind to the larger epitope (which Biogen discovered) as well as antibodies that bind to the smaller epitope (which Biogen did not).  Since enablement is determined as of the filing date, this presents the classic patent law hypothetical: Inventor X invents one way of curing a type of cancer and then claims simply "a cure for cancer."  Should inventor X be entitled to the claim?  She's cured cancer, after all.    

47 thoughts on “Biogen v. Glaxosmithkline: Prosecution History Disclaimer and Claim Construction

  1. 46

    Thanks, Ned. Sounds like you have the premise and the research for a good law article.

  2. 45

    They are not following Ned-IMHO law.

    There is a world of difference. See my post at 2:19 PM. Fish, you owe me a coke.

  3. 43

    And which FedCir cases have held that claims that are functional at the point of novelty are invalid?

  4. 40

    Fish, 1) Halliburton's holding was not limited to means. 2) Fuetterer gave "means" as an example. 2) Fuetterer indetified Westinghouse as the prior law. 3) Westinghouse held that if a claim was functional (function of a machine), it would be construed to cover the corresponding structure, etc. and equivalents thereof.

    Now what did I say? The Feds are trying to "cabin" 112, p.6 to "means" clauses when that was not the point at all in Halliburton, nor was it even important in Fuetterer. "Means" was used simply to denote a claim to structure that is functionally defined. Circle back to Westinghouse. Westinghouse's claim 2 was the source of the controversy. From opinion:

    "[T]he second claim, which is "in a brake mechanism, the combination of a main air-pipe, an auxiliary reservoir, a brake-cylinder and a triple-valve having a piston, whose preliminary traverse admits air from the auxiliary reservoir to the brake-cylinder, and which by a further traverse admits air directly from the main air-pipe to the brake-cylinder, substantially as set forth."

    "In the construction of this claim, the District Judge was of opinion that it was broad enough to cover other devices in which air was admitted directly from the train-pipe to the brake-cylinder by the further traverse of the piston actuating a valve admitting such air, and that the defendants could not exculpate themselves from the charge of infringement, from the fact that in their device the train-pipe air was admitted 554*554 through the triple-valve chamber, and not through a by-passage, nor by the fact that in their device the further traverse of the piston opens the main valve in a special manner, which produces the same result, but does not make use of a separate auxiliary valve.

    We have no desire to qualify the repeated expressions of this court to the effect that, where the invention is functional, and the defendant's device differs from that of the patentee 569*569 only in form, or in a rearrangement of the same elements of a combination, he would be adjudged an infringer, even if, in certain particulars, his device be an improvement upon that of the patentee. But, after all, even if the patent for a machine be a pioneer, the alleged infringer must have done something more than reach the same result. He must have reached it by substantially the same or similar means, or the rule that the function of a machine cannot be patented is of no practical value. To say that the patentee of a pioneer invention for a new mechanism is entitled to every mechanical device which produces the same result is to hold, in other language, that he is entitled to patent his function. Mere variations of form may be disregarded, but the substance of the invention must be there. As was said in Burr v. Duryee, 1 Wall. 531, 573, an infringement "is a copy of the thing described in the specification of the patentee, either without variation, or with such variations as are consistent with its being in substance the same thing. If the invention of the patentee be a machine, it will be infringed by a machine which incorporates in its structure and operation the substance of the invention; that is, by an arrangement of mechanism which performs the same service or produces the same effect in the same way, or substantially the same way… . That two machines produce the same effect will not justify the assertion that they are substantially the same, or that the devices used are, therefore, mere equivalents for those of the other."

    "But if the second claim be not susceptible of the interpretation that it is simply for a function, then the performance of that function must be limited to the particular means described in the specification for the admission of air from the train-pipe to the brake-cylinder. This we understand to be the theory of the defendants, and this raises the same question which is raised under the first and fourth claims, whether defendants' device contains the auxiliary valve of the Westinghouse patent, or its mechanical equivalent.

    In this view, it becomes unnecessary to express an opinion whether the second claim be valid or not, since in the aspect of the case most favorable to the complainants, it is necessary to read into it something which is not found there, or, in the 558*558 language of complainants' brief, "to refer back to the specification; not, it is true, for a slavish adoption of the identical instrumentalities therein described, but for the understanding of the essential and substantial features of the means therein illustrated." In thus reading the specification into the claim, we can adopt no other construction than to consider it as if the auxiliary valve were inserted in the claim in so many words, and then to inquire whether the defendants make use of such valve, or its mechanical equivalent."

  5. 39

    I shudder to ask Ned why he feels that the Donaldson case supports his view here.

  6. 38


    Donaldson says “In Halliburton Oil Well Cementing Co. v. Walker, 329 U.S. 1 [71 USPQ 175] (1946), the Supreme Court held that means-plus-function language could not be employed at the exact point of novelty in a combination claim. Congress enacted paragraph six, originally paragraph three, to statutorily overrule that holding. See In re Fuetterer, 319 F.2d 259, 264 n.11, 138 USPQ 217, 222 n.11 (CCPA 1963) (noting that it was Congress’s intent to restore the law regarding broad functional language in combination claims to its state prior to Halliburton)”

    This does not make your point, I contend.

  7. 35

    That’s certainly true for anyone practicing the oldstep

    unless of course, it’s not.

    Now tell everyone

    Now? C’mon Malcolm, I’ve posted the counterpoints many many many many times (even already on this thread).

    You continue to ignore them. Run away from them. Stick your head into a piles of crp to avoid them.

    Your turn to provide (gasp) answers!

    Try not to implode into your usual pile of vacuous intellectual dishonesty.

  8. 34

    the counter points

    LOL. All claims in the form [oldstep]+[newthought] are ineligible because they effectively cover the [newthought]. That’s certainly true for anyone practicing the oldstep!

    Now, tell everyone your “counter point”, Humpty. In other words, counter my statements above with a fact that is irreconcilable with what I am stating. Tell everyone where there is a flaw in the logic. Otherwise, you are not making “counter points,” Trollboy. You’re just trolling, as usual.

  9. 33

    LOL – that’s not sand you and Ned are plunging your skulls into Malcolm.

    That’s just more of your canard crp.

    And your pet theory of effectively claims to just a [newthought] STILL do not account for perfectly valid claims containing only [oldthought]s as well as what the state of controlling law is in regards to having mental steps (yes – perfectly allowed as steps).

    Try a little intellectual honesty. Perhaps Francis has some over at PatentDocs…

  10. 32

    I want a cite for what you and Ned seem to be proclaiming is the law (you know, the actual point under discussion).

    Try to keep up, son.


    Yawn. Your theory is still total bunk. You still have not addressed the counter points raised (like perfectly valid claims with only [oldstep]s much less [oldstep]s and [new thoughts], or what the current controlling law is on claims containing mental steps), – you know, the same counter points continusously raised that you never have eal answers for.

    And your “love” of that 9-0 decision still does not support what you think it does AND will still sink your position on the Products of Nature (well, at least you rold position, prioor to you adopting what I long told you about and that somehow you never could quite seem to understand).

    Keep on loving your self-defeat Malcolm – that guarantees more of that self-defeat that you have become famous for.

  11. 31

    simple concept that [oldstep]+[newthought]

    LOL – talk about canards.

    What would Francis say?

    I know – that’s not sand you are plunging your skull deep into. It’s Malcolm’s typical crp.

  12. 30

    Fish, it would be good if you would be a bit more explicit.

    He is explicit Ned. He is asking you to provide a cite that proves your suggested point that functional claiming “at the point of novelty” NOT being allowed is current law. You no, as he asks, “cases which are particularly on point.”

    Thing is, you will not because you cannot. Thus you will now simply try to tank yet another thread, and avoid backing up your canard with real law. Instead we have you asking questions and wanting something from him. Sorry Ned, the ball is in your court.

    This may come as a shock to people, but you pull this same trick everytime you are asked for substantive backing for your desired state of law. I suggest that you try a little intellectual honesty in its place. I’ve got no problem with the idea that you think the law should be different, but please, let’s put a stop to the naked assertion that your canards are the law of the land.


  13. 29

    Lemley seems be coming to the same conclusion, but from a different angle.

    The only way to come to a different conclusion is to plunge your skull deep into the sand and pretend that basic logic is really, really hard to follow. But our patent tbgger friends excel at that behavior. See, e.g., the discussions here prior to the Prometheus decision when the simple concept that [oldstep]+[newthought] claims were effectively claims to the [newthought] itself was greeted as if it were the solution to the Hodge Conjecture written in hieroglyphics.

  14. 28

    cite please.

    You need a cite for the proposition that functional claiming of a composition at the point of novelty is a problem in both article of manufacture and method claims?

    Hmm. Reminds me of when you asked over and over again for a cite that claims in the form [oldstep]+[newthought] were either ineligible or anticipated. Remember how that turned out, anon?

    I do. 9-0. I’m still loving it.

  15. 27

    “a bit more specific” okay, a couple of FedCir case which held that Claims are invalid if they are functional at the point of novelty.

  16. 26

    Fish, it would be good if you would be a bit more explicit. However, what I see the Feds doing today is trying to cabin 112(f), trying to find any reason not to construe the claim as a MPF claim — even if it uses the “magic words.” If there is a case to the contrary, recent case, please cite it.

  17. 24

    And, might I add, that Lemley seems be coming to the same conclusion, but from a different angle.

    It would be interesting if Lemley were to actually read Westinghouse some day and understand its holding.

  18. 23

    Fish, lots of them. Just check the “how cited” link in the above link to Fuetterer.

    It is odd, don’t you think, that Rich believed, and the many law reviews are in accord, that Westinghouse was “restored” when today 112(f) is carefully cabined to MPF claims? Westinghouse was not limited to MPF claims. It applied generally to functional claims.

    The “odd” part is that the some on the Federal Circuit seem wont to narrowly cabin 112(f) to claims that expressly use the magic language, when the intent of Congress was not so limited as stated repeatedly by those involved with the ’52 Act.

    Thus we have the absurd result that many claims are expressed functionally, e.g., such as “configured to” perform a function, and are construed without regard to Halliburton or to Westinghouse simply because they do not employ “means for.” That result is contrary to Congress’s intent.

  19. 22

    irrelevant when the only new element is a functionally-claimed composition. That’s not the case with the Myriad’s composition claims.

    LOL – cite please.

    Oh wait – you don’t do answers.

    LOL (shine that helmet of yours to a fine gloss).

  20. 21

    There are, but not in Ned’s favor.

    He labels these as ‘not in accord’ with Ned’s Law.

  21. 19

    It will not avail you

    Odds that Trollboy learned English from watching medieval costume dramas on UHF?

    the type of claim here (process).

    Whether it’s a process or an article of manufacture is irrelevant when the only new element is a functionally-claimed composition. That’s not the case with the Myriad’s composition claims.

    your shiny helmet.

    Right, the one you love to touch. Get help, Trollboy.

  22. 18

    And, I might add, Fish, that if Congress truly intended to overrule Halliburton and restore Westinghouse, cf. fn. 11 of Fuetterer, then it would not have intended to limit its application to “means for” type claims. Actually, “means for” was suggested to be an “example” in the note.

    11. We do not mean to imply that 35 U.S.C. § 112 was not in derogation of the result reached in any case decided prior to the enactment of the 1952 Patent Act. See, e. g., Halliburton Oil Well Cementing Co. v. Walker et al., 329 U.S. 1, 67 S.Ct. 6, 91 L.Ed. 3. We feel, however, that a considerable body of case law, if not the preponderance thereof, before the Halliburton case interpreted broad statements of structure, e. g., “means,” plus a statement of function in the manner now sanctioned by the statute. See, e. g., Westinghouse v. Boyden Power Brake Co., 170 U.S. 537, 558, 18 S.Ct. 707, 42 L.Ed. 1136. See also in this regard the February 1952 issue of the American Patent Law Association Bulletin wherein is reprinted at pp. 40-50 an address by the Hon. Joseph R. Bryson, Representative from South Carolina, given on January 24, 1952, to the Philadelphia Patent Law Association. Representative Bryson was at this time Chairman of Subcommittee No. 3 of the Judiciary Committee of the House of Representatives, which subcommittee was in charge of the legislation which resulted in the Patent Act of 1952. He stated in part (at pp. 45-46):

    “I should like to say a word on the provision in the bill for functional claiming. [H.R. 3760, 82d Cong., 1st Sess., § 112 (1951)] * * *. This provision in reality will give statutory sanction to combination claiming as it was understood before the Halliburton decision. All the elements of a combination now will be able to be claimed in terms of what they do as well as in terms of what they are.” [Emphasis ours.]

    For a more complete analysis of the cases under the third paragraph of 35 U.S.C. § 112 since its enactment, see Woodcock, “Patent Act of 1952 — Ten Years of Interpretation: Section 112,” p. 157, American Bar Association Section of Patent, Trademark and Copyright Law, Summary of Proceedings at San Francisco, California (1962).

    link to

  23. 16

    Far more than Myriad’s composition claims,

    Nice attempt at dust-kicking.

    It will not avail you to attempt to dismiss the Myriad case and that case’s focus on the Product of Nature judicial exclusion by contrasting with the type of claim here (process).

    Your PON in functional terms argument is still a canard – a badly misapplied canard at that.

    Feel free to rejoin this world any time you want to take off your shiny helmet.

  24. 15

    1. A method of treating chronic lymphocytic leukemia in a human patient, comprising administering an anti-CD20 antibody to the patient in an amount effective to treat the chronic lymphocytic leukemia…

    Far more than Myriad’s composition claims, this type of claim (and others like it) could arguably run afoul of the prohibition against claiming “natural phenomenon.” As I noted above, the claim fails to recite any new or non-obvious composition that is “administered” to effect a treatment. Rather, the only difference between the recited method and the prior art methods is the recitation of a composition that is claimed in functional terms, i.e., an “anti-CD20 antibody.”

    In this case, the “phenomenon of nature” is that an antibody with a certain minimum affinity to the CD-20 antigen will, upon binding, cause the destruction of B-cells in the bloodstream (and other tissues) which express that antigen. Rather than develop and claim specific, novel and non-obvious compositions with the necessary properties (and methods of administering same in a CLL treatment protocol), the strategy pursued by Biogen was simply to claim the genus of all such applications.

    The corresponding composition claim could be written as “An anti-CD20 antibody, wherein said antibody is capable of treating CLL when administered to a patient in need thereof.” As is the case with the claim at issue in the notorious Funk Brothers case, such a claim captures all solutions to a technical problem (in this case, preparing and identifying antibodies with the requisite properties). In exchange for that broad scope, the patentee in this type of case typically provides the public with (at best) one working embodiment (i.e., an actual antibody), and that embodiment need not be structurally distinguished from other antibodies (in some cases a biological deposit may be required to show enablement; cf Scripps v. Genentech (CAFC 1991)).

    At present, this functional claiming practice is categorically permitted by the USPTO (and the Federal Circuit) in the context of antibodies. It seems increasingly doubtful that the Supreme Court would approve.

  25. 13

    Why would I be pointing this out

    1. You were bored
    2. You’re only 4,238 comments away from your previous record
    3. Instructions received by the transmitter in your fillings was very clear about the necessary content of your comment
    4. All of the above

  26. 11

    Try to keep up Malcolm.

    Why would I be pointing this out if my “sh-tty imaginary” clients be the focal point?

    Better trolling please.

  27. 10

    Is there some new result here, or is it just a straightforward application of disclaimer/estoppel to the typical prosecution history, which is typically ambiguous/unambiguous depending on who you represent. I think this is just a nice example of typical, good for reminding us of the issue.

  28. 7

    It’s one of his favorite (and most ridiculous) canards.

    Guess which third party interest it would work against?

  29. 4

    anon, what is clear is that the Federal Circuit is avoiding the PON issue like a plague. They are magnifying the problem by a crab-like limitation of 112(f) to claim elements that expressly include the magic words and do not have any structure. So that lets patent attorney to claim functionally. Moreover, the Federal Circuit seems to want to give such claims their full scope, leaving enablement challenges as the sole refuge to those include to litigate such things.

    It is remarkable that the someone hasn’t raised the issue of functional claim in a clear enough manner so that the Federal Circuit cannot avoid it.

  30. 3


    Wyeth v. Stone, O’Reilly v Morse, Perkins Glue, Wabash Appliance and Halliburton were uniform in holding invalid claims functional at the point of novelty.

    Glaringly, Westinghouse v. Boyden Power Brake stands as the sole exception. That case would not hold such claims invalid, but would rather construe them to be limited to the corresponding structure, materials and acts described in the specification and equivalents. Halliburtion is seen as overruling Westinghouse, however.

    112(f) (formerly p.6, p.3 as enacted) was thought to restore and codify Westinghouse, but the drafters botched that job by limiting the authorizations to claims to “means for” and “step for” and then only to combinations. The original drafters had intended to simply enact Westinghouse. They failed, and arguably, Westinghouse remains overruled.

    The Federal Circuit seems to want to avoid the issue (functional claiming at the PON) entirely. Apparently, from the linked post, if the issue is presented, they decide the case on other grounds.

  31. 2

    The PTO’s job is to make sure any limiting arguments made by applicants find their way expressly into the claims

    Um, no. If you have, as you state, a strong view of phd (or phe), then such an “expressly finding into claims” is not necessary and is quite superfluous.

    Try being less anti-patent in your leanings, Malcolm.

    As for the rest of the B$ PON crp. Well, it is stil just crp with no tether to the current world (this world – Malcolm’s world may differ, and you need your own shiny hat for entry).

    As for the Eli Lilly bias,… (LOL – go figure)

  32. 1

    A better result would have been invalidating the claim for lack of enablement or written description.

    As for Plager, his comment:

    Making too much of such ambiguous statements ‘does not advance the patent’s notice function or justify public reliance.'”

    is 180 degrees backwards. It’s when too little is made of such “ambiguous” statements that the notice functions of patents “goes entirely by the wayside”. Everything in the prosecution history is relevant, everything must be considered, and the functioning of the system depends on applicants being bound by those statements, whether such statements are “broadening” and render the patent obvious or non-enabled, or whether such statements are narrowing and result in “worthless” non-infringed claims. The PTO’s job is to make sure any limiting arguments made by applicants find their way expressly into the claims. The proper role of the court is to protect the public (not patentees) from failures by patent applicants and the USPTO.

    As for Prof Crouch’s “avoided question”:

    Since enablement is determined as of the filing date, this presents the classic patent law hypothetical: Inventor X invents one way of curing a type of cancer and then claims simply “a cure for cancer.” Should inventor X be entitled to the claim?

    the answer to that hypothetical is certainly “of course not!” But if we focus on these particular claims just a little bit more, there’s definitely something interesting there. First, they are far, far narrower than the “cure for cancer” proposed in the hypothetical. But astute readers will notice right away that the claim is a near-perfect example of a very rare instance of biotech-industry coddling by the judiciary: functional claiming at the point of novelty (a perfect example would be a composition claim to the antibody). Specifically, this is the so-called “antibody exception” to the laws that require claims to new compositions to recite structures that distinguish the new compositions from compositions in the prior art.

    See Professor Liivak’s previous article on this topic here:

    link to

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