Narrative Opinion Summary
This case concerns a patent infringement dispute between Purdue Pharma and Faulding Inc., involving Purdue's U.S. Patent No. 5,672,360, which claims a method for treating pain with a once-daily opioid formulation. Purdue alleged that Faulding's product, Kadian, infringed the '360 patent. Although the District Court for the District of Delaware found infringement, it invalidated the patent claims due to an insufficient written description under 35 U.S.C. § 112. The court determined that the Cmax/C24 limitation was not adequately described in the original application, rejecting Purdue's interpretation of the term 'substantially flat' serum concentration curve. The court also dismissed the examiner's supportive findings as unpersuasive in light of contrary evidence presented during the trial. Purdue's reliance on precedents such as Dickinson v. Zurko to uphold the examiner's decision was deemed inapplicable, as the case was an infringement action, not a PTO appeal. The appellate court upheld the district court's decision, affirming the claims' invalidity and rendering Faulding's cross-appeal on the infringement issue unnecessary.
Legal Issues Addressed
Assessment of Patent Claims Based on Original Disclosuresubscribe to see similar legal issues
Application: The court found that the original disclosure did not adequately support the specific Cmax/C24 limitations Purdue later claimed, aligning with the principle that claims must be supported by the initial disclosure.
Reasoning: Applying this rationale to the '360 patent, the court found that the written description did not adequately indicate the significance of the Cmax/C24 ratio or motivate its calculation.
Deference to PTO Examiner's Decision and Standard of Reviewsubscribe to see similar legal issues
Application: The court noted that the standard of review from Dickinson v. Zurko was inapplicable as this was an infringement action, not an appeal from the PTO, and the district court was not bound to defer to the examiner's decision.
Reasoning: Purdue argued that the district court should have upheld the examiner's written description decision based on the Supreme Court's ruling in Dickinson v. Zurko, which pertains to the Administrative Procedure Act's standard of review.
Interpretation of Claim Terms and Invention Descriptionsubscribe to see similar legal issues
Application: The court rejected Purdue's interpretation of 'substantially flat' serum concentration curve, finding it did not equate to a Cmax/C24 ratio of two or less.
Reasoning: The district court rejected Purdue's interpretation of the term 'formulations which do not exhibit a substantially flat serum concentration curve,' asserting it relates to the rapid opioid release feature outlined in the original claims, rather than the Cmax/C24 ratio of more than two introduced in the amended claims.
Patent Infringement and Invaliditysubscribe to see similar legal issues
Application: Purdue Pharma alleged that Faulding infringed its '360 patent, but the court held that the patent claims were invalid.
Reasoning: The U.S. District Court for the District of Delaware found that while Faulding had infringed the patent, the asserted claims were invalid.
Role of Examiner's Findings in Written Description Requirementsubscribe to see similar legal issues
Application: The court found the examiner's statement supporting the claims insufficient to satisfy the written description requirement, given the evidence presented.
Reasoning: Purdue further contended that the district court improperly dismissed the examiner’s findings, which indicated that the new claims were supported by the specification.
Written Description Requirement under 35 U.S.C. § 112subscribe to see similar legal issues
Application: The court determined that the claims of the '360 patent did not meet the written description requirement as the Cmax/C24 limitation was inadequately described in the original application.
Reasoning: The district court ultimately ruled that while Faulding's product infringed the patent, the claims were invalid due to insufficient written description as per 35 U.S.C. 112.