Bilcare, KSR, Presumptions of Validity, Preliminary Relief, and Obviousness in Patent Law

55 Pages Posted: 15 Aug 2007 Last revised: 21 Feb 2010

Date Written: August 9, 2007


In Bilcare Ltd. v. M/S The Supreme Industries Ltd., the Delhi High Court affirmed a lower court order vacating ex parte injunctions against an alleged infringer of a patent, rejecting arguments that the patent should be presumed valid even though the patent was the subject of opposition proceedings. In KSR International, Inc. v. Teleflex Co., the U.S. Supreme Court reversed the U.S. Court of Appeals for the Federal Circuit's long-standing interpretation of Section 103 of the Patent Act, i.e., that a challenger seeking to prove invalidity must demonstrate a teaching, suggestion, or motivation to combine prior art references. These cases reveal important insights (within varying procedural and substantive legal contexts) into statutory and judicial presumptions of validity that result from the grant of patents by administrative agencies.

The article explains how such presumptions relate to evidence and proof rather than to the weight accorded to legal judgments. Using Bilcare as a reference, the article suggests that opportunities to present evidence challenging validity should be provided even in preliminary relief contexts, and discusses concerns that arise when validity is challenged in both administrative and judicial systems. The article then describes how the KSR decision adopted substantive legal rules for obviousness that supersede the statutory presumption of validity, shift the burdens of production and persuasion, and (for some inventions) limit the scope of relevant evidence that can be used by patent holders to prove non-obviousness. Finally, the article argues that the U.S. statutory presumption should not continue to be construed by the courts to impose heightened burdens of proving invalidity.

(Forthcoming in Spanish as translated by Carlos Correa, Revista Juridica Argentina La Ley)

Keywords: patent, patent law, presumption of validity, burden of proof, evidence, rebuttal, administrative procedure, judicial review, invalidity, preliminary relief, obviousness, inventive step

JEL Classification: K20,K23,K33,K40,K41,L40,L65,O30,O31,O32,O33,O34

Suggested Citation

Sarnoff, Joshua D., Bilcare, KSR, Presumptions of Validity, Preliminary Relief, and Obviousness in Patent Law (August 9, 2007). American University, WCL Research Paper No. 2008-15, Available at SSRN: or

Joshua D. Sarnoff (Contact Author)

DePaul University College of Law ( email )

25 E. Jackson Blvd.
Chicago, IL Cook County 60604-2287
United States
312-362-6326 (Phone)

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