Patents

In re Cyclobenzaprine: Secondary Considerations Are Not an Afterthought

The Federal Circuit vacated an obviousness judgment because the trial court declared the claims obvious first and only then asked whether objective indicia could rescue them.

May 19, 2025
Extended-release medication capsules arranged on a pharmaceutical surface
The patents claimed an extended-release oral form of the muscle relaxant cyclobenzaprine. Shutterstock
Educational content, not legal advice. This article explains general legal concepts. It does not create an attorney–client relationship. For your specific situation, consult a licensed attorney.

In re Cyclobenzaprine Hydrochloride Extended-Release Capsule Patent Litigation (Eurand, Inc. v. Mylan Pharmaceuticals Inc.), Nos. 2011-1399, -1409, 676 F.3d 1063 (Fed. Cir. Apr. 16, 2012), is the case to cite when a court treats objective indicia of nonobviousness as a tie-breaker rather than as evidence. In an opinion by Judge O’Malley, joined by Judges Newman and Reyna, the Federal Circuit reversed a district court judgment that had held the asserted claims invalid as obvious. The trial court’s methodological error was both subtle and consequential: it found a prima facie case of obviousness first, and only afterward turned to the patentee’s evidence of long-felt need, failure of others, and commercial success to see whether that evidence could overcome a conclusion it had already reached. That sequencing, the Federal Circuit held, is legal error.

At a glance

  • Case: In re Cyclobenzaprine Hydrochloride Extended-Release Capsule Patent Litig., Nos. 2011-1399, -1409 (Fed. Cir. Apr. 16, 2012).
  • Panel: Judges Newman, O’Malley, and Reyna; opinion by Judge O’Malley.
  • Patents: U.S. Patent Nos. 7,387,793 and 7,544,372, covering an extended-release oral dosage form of cyclobenzaprine (marketed as Amrix) defined by a target pharmacokinetic (PK) profile.
  • Posture: Appeal from a district court bench-trial judgment of invalidity in consolidated Hatch-Waxman (ANDA) litigation against generic challengers.
  • Holding: Reversed. The district court (1) reached its obviousness conclusion before weighing objective indicia, and (2) improperly shifted the burden of persuasion to the patentee. Properly weighed, the evidence did not support invalidity.
  • Doctrinal core: Secondary considerations are part of the obviousness analysis itself, not a rebuttal stage; and the burden of persuasion on obviousness stays with the challenger throughout.

The technology and the obviousness theory

Cyclobenzaprine is a muscle relaxant long sold in an immediate-release tablet. The inventors developed an extended-release capsule designed to release the drug over roughly 24 hours, supporting once-daily dosing, and claimed it by reference to a particular set of PK parameters — measures such as peak plasma concentration and total drug exposure over time. The generic defendants argued that producing an extended-release version of a known immediate-release drug was a routine exercise: the building blocks of modified-release formulation were well known, so a skilled formulator would have been motivated to assemble them and would have had a reasonable expectation of success.

The district court accepted that narrative. It concluded that a person of ordinary skill would have been motivated to combine known formulation techniques to make an extended-release cyclobenzaprine product and would have expected success. Having reached that conclusion, the court then examined the patentee’s objective evidence and found it insufficient to disturb the result. The patentees — Cephalon and its co-plaintiffs — appealed.

Error one: putting indicia last

The Federal Circuit’s central holding is a statement about the structure of the obviousness inquiry. Under Graham v. John Deere Co., the analysis has four factual predicates: the scope and content of the prior art, the differences between the art and the claims, the level of ordinary skill, and objective indicia of nonobviousness. The fourth factor is not a separate, later phase. As the court put it, objective evidence “must always when present be considered en route to a determination of obviousness,” and such evidence “may often be the most probative and cogent evidence in the record.”

The district court inverted that command. By declaring the claims obvious and only then testing whether secondary considerations could rebut the conclusion, it relegated the fourth Graham factor to a rescue operation. The Federal Circuit explained why that is more than a formalist quibble. Objective indicia function as a check against hindsight. They are real-world signals — long-felt but unmet need, the failure of skilled competitors, unexpected results, commercial success tied to the claimed features — that tell a fact-finder whether the invention really was within ordinary reach at the time. A court that forms its obviousness judgment before consulting those signals has already committed the hindsight error the indicia exist to prevent. The fact-finder must weigh all four factors together before deciding.

Error two: shifting the burden of persuasion

The second error concerned burdens. A patent is presumed valid, and a challenger must prove obviousness by clear and convincing evidence. The Federal Circuit drew the now-familiar distinction between the burden of production and the burden of persuasion. The burden of production — the obligation to come forward with evidence — can shift during litigation; once a challenger makes out a prima facie case, a patentee will in practice want to produce rebuttal evidence. But the burden of persuasion never moves: it rests on the challenger, who must persuade the fact-finder of obviousness by clear and convincing evidence on the record as a whole.

The district court, the Federal Circuit found, had effectively required the patentees to disprove obviousness through their secondary-considerations evidence, treating the prima facie case as a presumption the patentee had to overcome. That is the wrong allocation. In litigation — unlike examination at the Patent Office, where the prima facie construct legitimately structures the back-and-forth between examiner and applicant — there is no formal burden-shifting that obligates the patentee to defeat a preliminary conclusion. The challenger must carry the ultimate burden after all evidence, including the patentee’s objective indicia, is on the table.

The reasonable-expectation-of-success problem

Re-weighing the record, the court also found the obviousness theory wanting on its own terms. The claims were defined by a PK profile, yet the record did not establish that a skilled artisan would have known how to achieve that specific profile, or that achieving it would predictably yield a safe and effective once-daily product. The court emphasized the absence of a known PK/PD (pharmacodynamic) relationship for cyclobenzaprine — that is, no established link between the blood-concentration profile and the therapeutic effect. Without that link, a formulator could not have had a reasonable expectation that hitting a particular PK target would produce a working drug. The objective evidence reinforced the point: others had not produced such a product despite a long-felt need, which is precisely the kind of real-world signal that undercuts a tidy after-the-fact combination story.

Open questions

  • Where is the line between production and persuasion in practice? Cyclobenzaprine is clear that persuasion stays with the challenger, but trial courts still must manage how and when patentees come forward with indicia evidence without inadvertently importing a rebuttal-style presumption.
  • How tight must the nexus be? Objective indicia count only when tied to the claimed invention’s merits. The opinion reaffirms the requirement of a nexus but leaves the granular nexus disputes — especially for claims defined by performance parameters — to later cases.
  • Does the same rigor apply at the PTAB? The decision arose in district-court litigation. How strictly the “consider indicia first” command applies in inter partes review, where the burden framework and evidentiary posture differ, has been the subject of continuing development.

Implications

  • For patent owners: Build the objective-indicia record early and tie each item — long-felt need, failure of others, unexpected results, commercial success — to the claimed features. Then insist that the court weigh that evidence as part of the obviousness determination, not as a rebuttal afterthought.
  • For challengers: Do not assume a prima facie case ends the inquiry. The burden of persuasion remains yours through the close of evidence, and a strong indicia record can defeat an otherwise plausible combination theory.
  • For trial courts: Sequence matters. Findings should address all four Graham factors together before announcing a conclusion, and the opinion should make clear the challenger carried the clear-and-convincing burden on the whole record.
  • For pharmaceutical formulators: Claiming by PK profile is powerful but demands proof that the profile was achievable with a reasonable expectation of success — particularly where no PK/PD relationship was known in the art.

Frequently asked questions

What exactly did the district court do wrong? Two things. It decided the claims were obvious before weighing the patentee’s objective evidence, and it effectively made the patentee disprove obviousness. The Federal Circuit held that indicia must be weighed within the obviousness analysis and that the burden of persuasion stays with the challenger.

Does this case mean secondary considerations always save a patent? No. It means they must be considered as evidence on the merits, alongside the other Graham factors, before any conclusion. Whether they tip the balance still depends on their strength and their nexus to the claimed invention.

How does the burden differ at the Patent Office versus in court? At the Office, a prima facie case structures examination and the applicant must respond. In litigation, the issued patent is presumed valid and the challenger bears the burden of persuasion by clear and convincing evidence throughout; there is no formal shift requiring the patentee to defeat a preliminary finding.

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