Positive Times for Negative Limitations

Recently, the Federal Circuit determined that a negative claim limitation, excluding a certain type of dosing in a method of treatment, satisfied the written description requirement even though the disclosure made no mention of the excluded dosing procedure.  Novartis Pharmaceuticals Corp. v. Accord Healthcare, Inc., No. 21-1070, Jan 03, 2022 (Fed. Cir. 2022)

The patent was directed to a method of treating (also a method of reducing or preventing or alleviating) Relapsing-Remitting multiple sclerosis comprising oral administration of the active compound fingolimod (or salt thereof) at a daily dosage of 0.5 mg.  The claims further included a negative dosing limitation, i.e., “absent an immediately preceding loading dose regimen.”

For a patent to provide written description for a negative limitation it is not necessary for the disclosure to include an express statement of exclusion (e.g., a process comprising steps a, b, and c, without step d).   See, e.g., AC Technologies S.A. v. Amazon.com, Inc., 912 F.3d 1358 (Fed. Cir. 2019).  In fact, an express statement of inclusion can provide written description support for a negative limitation.  See, e.g., In re Johnson, 558 F.2d 1008 (CCPA 1977).

In Novartis the claimed method of treatment excluded a preceding loading dose regimen, i.e., a higher dose usually given before the first daily dose.  However, the specification never mentioned a loading dose or the absence thereof.  In finding written description support for this negative limitation the court repeatedly stated that there is not a heightened written description standard for negative limitations.

The specification described a prophetic human clinical trial in which “Initially patients receive treatment for 2 to 6 months.”  Supported by expert testimony, the court found that describing this treatment as initial provided written description support for exclusion of a preceding loading dose regimen, even though the specification was silent on the use of a loading dose.  One expert testified that there were two logical places “that if there was going to be a loading dose, it would have been stated.”


Practice Tip:

Arguably, “initially” could be said to, in general, exclude all forms of preceding dosage regimes that differed from the daily dose (e.g., a preceding titration dosage regime?).  Yet, the claim only excluded one type of dosage regime.  This case might be beneficial to practitioners looking to add a specific negative limitation, supported by a more general statement in a disclosure.


If you have any questions regarding the use/strategy of using negative claim limitations, please contact Brion Heaney at Heaney@mwzb.com.


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