Patent Invalid Where Applicant Implied It Had Empirical Data That It Did Not Have

Case: Purdue Pharma L.P. et al. v. Endo Pharmaceuticals, Inc. et al., Case No. 04-1189, -1347, & 1357, (Fed. Cir. June 7, 2005)

The One Sentence Summary: The Federal Circuit held that the patentee committed inequitable conduct where he misled the patent office by implying during prosecution that he had experimental data supporting the key feature he used to distinguish the patents at issue over the prior art, when in fact, the distinguishing feature was based on the inventor's insight and not on clinical trials.

What They Were Arguing About: Purdue held patents on a controlled release oxycodone medication for the treatment of moderate to severe pain. Endo filed an application with the FDA for approval of a generic version of the drug. Purdue sued Endo for patent infringement. During an 11 day trial, Endo put on evidence that Purdue committed inequitable conduct before the Patent and Trademark Office when it repeatedly argued that it had "surprisingly discovered" that the controlled release formulation of its drug controlled pain over a substantially narrower range of dosing than other opium-derived pain relievers. In fact, the "discovery" was nothing more than the inventor's "insight," in which, based upon his knowledge of the pharmacological properties of opium-derived pain relievers, he "envisioned" a controlled release product that would control pain over a small dosage range. Purdue had no clinical data supporting its "discovery."

Federal Circuit Rulings: The Federal Circuit affirmed the district court's finding that the patents were invalid because of Purdue's inequitable conduct before the PTO.

• The Federal Circuit reviews a district court's factual findings regarding materiality and intent to deceive for clear error, and will not disturb them on appeal unless the court has a "definite and firm conviction that a mistake has been made."
  
• The Federal Circuit refers to the standard for "materiality" set forth in PTO Rule 56, and looks to the version of the rule that was in place when the patents were pending.
  
• Purdue's misrepresentations were material because the lack of scientific proof that the drug worked over a reduced range of dosage was inconsistent with the inventor's representations to the PTO that he had "discovered" that OxyCodone acceptably controlled pain over a reduced dosage range.
  
• Although a patent application for a pharmaceutical discovery does not need to be supported by clinical results, see 35 U.S.C. Section 103(a) ("Patentability shall not be negatived by the manner in which the invention was made"), Purdue's repeated representations to the PTO that it had made a "surprising medical discovery" without disclosing the lack of clinical trials and that the alleged "discovery" under these circumstances was based on insight and was without an empirical basis, was a material misrepresentation.
  
• Even if the examiner did not necessarily rely on the applicant's misrepresentation, that would not be inconsistent with a finding of materiality.
  
• Intent to deceive or mislead the PTO need not be proven by direct evidence. The court can draw an inference of intent to deceive from the circumstantial evidence. Although a court must weigh all evidence, including evidence of good faith, "a patentee facing a high level of materiality and clear proof that it knew or should have known of that materiality, can expect to find it difficult to establish subjective good faith sufficient to prevent the drawing of an inference of intent to mislead. The district court did not err in drawing an inference from Purdue's statements and the context in which they were made. Purdue's carefully chosen language suggested that it had obtained clinical results, and that suggestion was left unclarified by any disclosure that discovery of the narrow dosage range for OxyCodone was based on insight."