Billion Dollar Verdicts Wiped Out Due to Patent Law’s Written Description

Imagine your billion dollar win wiped out later. You’d be mad. You’d wonder how that happened. You’d ask if you did anything wrong to deserve that wipe out. You’d ask if you could have done something different. Patent law’s “written description” invalidity has wiped out wins by ruling the patent was indeed invalid. Naturally each case depends on their own unique facts and circumstances, but this article will bring us up to speed (a little) on what’s happening now. And it may take years of litigation and millions of dollars in legal fees to sort it all out in a case.

Section 112(a) of the patent law describes various requirements of the patent specification: “a written description of the invention, and of the manner 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.” 

Embedded in the statute are three requirements: a written description, the enablement, and the best mode. For Written Description, in exchange for a limited period of exclusivity, inventors must disclose their invention to the public. Because the Written Description is a description of the invention, Section 112(b) identifies the invention as being what is claimed. See Section 112(b): “The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.” The original patent law, the Patent Act of 1793, did not have a distinct claim requirement. Rather the invention was fully described in the text. To this end, the requirement of a full written description did not change since 1793, despite the requirements that the invention be claimed in a claim (starting with the Patent Act of 1836). 

Now, plainly the scope of the invention is defined by the claims. Another question is whether the Written Description must describe the full scope of the invention no matter how reasonable/unreasonable it is, or is the scope determined under some reasonableness standard. Thus, the question is how must disclosure of the invention is needed? That is, how detailed or how generalized must the disclosure be and are there any contours as to any details that must be disclosed. The Court of Appeals for the Federal Circuit (CAFC) is often called the supreme court of patent law because the actual Supreme Court rarely takes patent cases and that the CAFC is the sole appellate court. 

Written Description and “Possession of the Invention”

The CAFC requires, aside from the enablement requirement, as a separate requirement within the written description, that the inventor(s) demonstrate a “possession” of the full scope of the invention, including every possible variation of each component. Ariad Pharms., Inc. v. Eli Lilly & Co., 598 F.3d 1336, 1351 (Fed. Cir. 2010) (en banc); AbbVie Deutschland GmbH & Co. v. Janssen Biotech, Inc., 759 F.3d 1285, 1301 (Fed. Cir. 2014). In pharma/biotech, claims are often claimed as a “genus” claim, for which the CAFC’s possession test asks if whether the patent discloses a representative number of species falling with that scope of the claims or sufficient structural features or structural features common to the genus members so that the person of ordinary skill in the art can visualize or otherwise recognize the members of the genus. Ariad, 598 F.3d at 1350.

The CAFC’s “possession of the invention” test is under current attack in the Juno Therapeutics v. Kite Pharma case, in which the CAFC invalidated the Juno patent based on the “possession of the invention” part of written description. The Supreme Court denied certiorari on Nov. 7, 2022 (Docket No. 21-1566). But because the Supreme Court granted the certiorari petition in Amgen Inc. v. Sanofi (Docket No. 21-757) on Nov. 4, 2022, Juno filed a petition for re-hearing on its certiorari petition in view of the Amgen grant. Juno re-argues that the Supreme Court should grant its cert petition because both cases involve the same patent statute (here 35 U.S.C. §112(a)) and involve the same written description phrase. Albeit, the Amgen case is more about the “enablement” requirement to make and use the claimed invention, whereas Juno’s petition is about the “possessing the full scope of written description” portion. 

Biogen v. Mylan relating to dimethyl fumarate (Biogen’s Tecfidera®) is another “how much details is needed” case, and the Supreme Court denied the certiorari petition (Docket No. 21-1567). Here, the patent specification described dozens of molecules, capable of treating dozens of disease conditions, in dozens of different strengths. The patent claimed a specific method of using a specific molecule for a specific disease in a specific dose. According to Biogen’s cert petition, the Federal Circuit screwed up by invalidating the patent. The Federal Circuit reasoned that the patent specification did not include data proving the efficacy of the claimed dose, the claimed dose was “listed only once” in the specification, and the claimed dose was not singled out from the other inventions described in the patent. The patent specification did not include any data or examples of the now-claimed method of use. But under Written Description, is that really required? That is, if the precise words can be found in the patent text, does Written Description require that the disparate words now found in the claim be demonstrably stitched together in the specification?

Said another way, does Written Description only require that the now claimed words be found in the specification or is more required? For example, suppose that a certain restaurant menu lists a dozen appetizers, a dozen main dishes, and a dozen side dishes, and a dozen desserts. Akin to patent law, is Written Description satisfied simply by arbitrarily plucking out one appetizer, a main dish, a side order, and a dessert? But suppose that the menu also includes a dozen “chef’s recommendations” that has a few preferred dinners comprising just a few preferred appetizers, a few main dishes, a few side orders, and a few desserts. Akin to patent law, is there a Written Description if the patron orders a meal that has one or more of the preferred items even though the precise meal now chosen isn’t expressly defined in the recommended list? Under the former, proponents of an explicit written description could simply copy an entire dictionary (or pharma textbooks) into the specification and satisfy written description because each word of the claim can explicitly be found in the specification text. Under the latter, though there is no precise meal described, some guidance of a good meal can be divined by the list of items in combination with the chef’s guidance/recommendations as to what few appetizers go with mains, sides, and desserts. That is, the chef’s recommendations help teach a preferred (though undescribed) meal. 

Written Description and Negative Limitations

A negative limitation is where the claim attempts to exclude something from consideration. It usually occurs when a potentially broader claim for a class of items is being rejected when a piece of prior art discloses a member of that class. The patent applicant then amends the claim to specifically exclude that item in the prior art. The issue is whether there is a basis for this exclusion or negative limitation. And the question of the negative limitation may be part of the claim construction analysis.

  In Santarus v. Par Pharm, the Federal Circuit held that it is not enough just to exclude the element from a claim. Rather there must be written description support to justify the exclusion. That is, one must examine the stated reasons for the exclusion. Such reasons can include, for example, an explanation of the disadvantages or the inoperability of the excludable item.

As a practical matter, a patent drafter ought to include satisfactory description of the elements to be excluded, a rational basis for doing do, etc. The drafter ought to be aware that in Markush group claims, a disclosure of any member of the Markush group can invalidate the claim. Therefore, a draftee may also wish to include description and rationale as to why any member of the Markush group can be excluded.

Accordingly, in the regime of negative limitations, there are several ways to examine them. On extreme is that a negative limitation now claimed must have explicit support and an explained rationale for the negative limitation. For example, suppose a claim includes a negative limitation that says, “wherein the drug formulation does not contain XYZ.” An explanation in the specification that states that XYX is not to be included in the formulation because XYZ is known to cause a destabilization of the active ingredient. The opposite extreme is where the negative limitation has actually no verbiage in the specification at all and hence no rationale. For example, suppose the specification does not even mention XYZ ingredient at all, but was added via amendment to the claim to overcome an Examiner rejection that XYZ was in the prior art. Here, the amendment added the “does not contain XYZ” limitation but there is no support for it. A middle ground, for example, would occur where XYZ is included in a list of possible ingredients, the Examiner cites prior art that XYZ ingredient exists, so the claim is amended to exclude XYZ from the formulation and overcome the prior art. Here there is no explicit rationale in the specification and the only putative rationale is to exclude an item from a list that the patentee said could be included, but for prior art purposes, it is now excluded. This latter philosophy may be troublesome because the specification describes the XYZ ingredient as useable (i.e., permissible) but now ejects it from consideration. 

In the context of claim construction, the court stated that negative limitations must be explained fully. It would be logical that written description negative limitation interpretation be construed consistent with claim construction tools. Furthermore, employing a stricter standard to written description and negative limitations would preclude extensive and protracted litigation over the negative limitation because such potentially invalidity would be discernible from the four-corners of the specification. As such, hired expert witnesses would not be permitted to cobble together disparate statements and ambiguous statements to either argue for or against written description. Such a standard would promote certainty for both patentees and competitors because it would not require the Federal Circuit’s interpretation years later (and millions of dollars in litigation spent) to know if the negative claim limitation has support or not. 

Novartis v. HEC Pharma (regarding the drug fingolimod) addressed some aspect of negative limitations. The Federal Circuit’s process was a little strange. The trial court ruled the patent valid and infringed. On appeal, a CAFC panel majority (of Judges O’Malley and Linn) affirmed validity and infringement, with Judge Moore dissenting. HEC petitioned for panel re-hearing and/or en banc review. Meanwhile, Judge O’Malley retired and was replaced by Judge Hughes on the re-hearing petition. The CAFC granted the petition for rehearing by the new panel and invalidated the patent. Judge Linn, then in the majority, was now a dissenter. Judge Hughes joined Judge Moore on the new majority panel. In effect, the one judge replacement caused the ruling to be reversed. The CAFC then denied the petition for re-hearing en banc. The Supreme Court initially granted Novartis’ application to stay the CAFC mandate but ultimately denied the application, thereby allowing the CAFC mandate to enter. Assuming Novartis petitions to the Supreme Court, it will be yet another written description case the Court may entertain. 

At issue there is/was that the claim had negative limitation to the absence of a preceding loading dose, which language does not appear anywhere in the text. Here, the negative limitation was allegedly supported (or unsupported depending on the perspective) only through expert testimony as to what was or was not present or what could or could not be divined from disparate portions of the text. 

Finally, written description rears its head in the ability to claim the benefit of the earlier filing date of previous applications. This means that early applications have to have sufficient written description if the patentee wants to rely on the description for later applications. A failure to show adequate support could result in invalidity of the later patent on its own or because intervening prior art invalidated it. 

Practical Considerations

Section 112(a) requires a written description of the invention as defined by the claims. Understandably, claims are amended during the application process, but this does not mean the applicant has free liberty to add any limitation to overcome the prior art. For example for negative limitations, suppose a pharma-based patent applicant is experiencing difficulty in prosecution and as a last ditch effort amends the claim to include a “wherein the formulation does not include strychnine.” The amendment presumably would overcome prior art because no formulation would contain the strychnine. A competitor would not include strychnine in a competitive formulation. So should such a meaningless claim limit be allowed? Or should a savvy patent applicant include an explicit negative limitation in the text, provide a rationale for it (e.g., strychnine is a poison and not suitable for drug formulations), and then be able to whip it out as an amendment to overcome a rejection? 

As stated above, because applicants can file new applications, add new matter once developed, claim the benefit of an earlier filing date (i.e., priority), perhaps the better rule should err on the side of more explicit disclosure, more rationale for negative limitations, more examples of representative species, more clinical data, etc. This rule would help provide certainty. Patent applicants have the ability to draft applications fully and then amend them. Further, as new data becomes available, new applications can be filed. There surely is a tension between how much disclosure is made initially that might then be used as prior art against later applications. But the failure to include disclosure may not permit sufficient amendment support later. 

Albeit that patent applicants are in control of the sufficiency of the disclosure written, the timing of R&D, and when applications are filed, the U.S. patent law change to a “first to file” system versus the previous “first to invent” system may impact patent applicants. If patent applicants delay filing applications until there is greater sufficiency of disclosure, more R&D is conducted to find not just one but many representative species within a genus, etc., then competitors may file their applications first and get priority of invention. Perhaps a genus is so large that one could never develop sufficient species to fully comply with the written description law. Finally, applicants could be deprived of valuable capital infusion through investment because one criteria for investors is whether there is enough I.P. to protect the future investment and patent applications filed are one measure of “enough I.P.” The lack of patent applications filed (because of intentional delays) could jeopardize investment opportunities. Moreover, the cost of acquiring patents could increase because broad genus-type applications may not suffice any longer and applicants will file multiple applications, having their own attendant costs. Though, in the pharma-biotech industry the cost of filing more applicants is usually not a singular deterrent. Finally, a company may choose to keep R&D as a trade secret instead of filing patents and the subsequent disclosure to the public. 

How we can help you?

We help clients in patent litigation, appeals, counseling, opinions of counsel, and PTAB proceedings. When your current firm needs help or the client needs a change of counsel, we can help. Our firm routinely provides due diligence advice on patent portfolios, can analyze patents for potential written description issues, can assist companies in broaden the portfolio it has. We also handle litigation if a competitor needs to invalidate broad patents. 

About Upadhye Tang LLP 

Upadhye Tang LLP is an IP and FDA boutique firm concentrating on the pharmaceutical, life sciences, and medical device spaces. We help clients with navigating the legal landscape by helping on counseling and litigation. Clients call us to help move drug and device approvals along and to represent them in IP and commercial litigation. Call Shashank Upadhye, 312-327-3326, or by email:, for more information. 

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