Written Description: Are We Headed for a New Era of Heightened Messier Requirements?

At least pharmaceutical patents in the US may be headed for more stringent application of written description requirements as well as a more confusing unfocused analysis as evident from the decision Biogen v. Mylan denying Biogen’s petition for panel rehearing and rehearing en banc.  The three Judge dissent clearly indicates a strong disagreement among Federal Circuit Judges.  See decision at https://cafc.uscourts.gov/opinions-orders/20-1933.ORDER.3-16-2022_1922220.pdf

The Dissent voices a strong opinion that the original decision from which rehearing was requested improperly and inconsistently with well-established precedent imported extraneous considerations into the written description analysis and blurred the boundaries between the written description requirement and the other statutory requirements for patentability, e.g., enablement.

The dissent alleges four specific points of error in the decision:

1) the panel majority and the district court overly emphasized unclaimed disclosures in the specification;

2) they erroneously imposed a heightened burden on the patentee to show that the specification proves efficacy;

3) they imported legal factors from other patentability requirements; and

4) they were influenced by irrelevant extrinsic evidence.

The majority decision according to the dissent focused on the amount of disclosure of the claimed subject matter versus the unclaimed subject matter, while in the opinion of the dissent, the claimed method was explicitly disclosed and such should have been adequate.  The majority opinion also questioned whether the claimed dose was therapeutically effective, which is typically a concern in an enablement context and not a written description context, with the latter usually being concerned about whether the skilled reader of the patent disclosure can recognize that what was claimed corresponds to what was described.  The majority also considered inventorship issues and what could be extrapolated from each inventor’s research at the time of filing as well as the disclosure drawing one’s attention to a different dose than claimed as being the most effective, thereby allegedly inserting a best mode analysis as somehow taking away from the description of what was claimed.  Moreover, the majority focused on extrinsic evidence in the form of clinical trials before filing and whether such would have been sufficient to show the efficacy of the particular dose recited in the claim.

In sum, it appears that the decision Biogen v. Mylan paves the way for the insertion of a variety of considerations / inquiries into the written description requirement, thus, making it messier as well as less predictable even in cases where the disclosure does provide explicit disclosure of the claim recited elements.

One way forward is to write narrower patent applications providing significant focus on the invention claimed and avoiding additional disclosures.  However, such is hardly an easy task to do where fallback positions are needed, e.g., for a variety of indications in case of a general pharmaceutical patent application, or for details such as doses, etc., where further research may still be ongoing to refine the final details.

If you have any questions regarding the content above, please contact Csaba Henter at Henter@MWZB.com


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