Purdue Misled Patent Office, Never Had Clinical Trial Data

July 8, 2005

Jeffrey Light, Patients not Patents

On June 7, 2005, a Federal Appeals court invalidated three Purdue Pharma patents for a controlled-release version of its pain-killer drug OxyContin (generically oxycodone). Purdue Pharma LP v. Endo Pharmaceuticals Inc., 2005 WL 1330933 (Fed. Cir. June 7, 2005). The appeals court affirmed a lower court’s ruling that Purdue Pharma had committed misconduct by falsely stating that it had experimental results about the claimed compound.

Endo Pharmaceuticals is planning to immediately launch a generic version of controlled-release oxycodone in four strengths: 10mg, 20mg 40mg, and 80mg. As the first generic maker, Endo will receive a 180-day exclusive marketing period for the products. The company is also pursuing a claim that Purdue’s conduct amounted to a violation of antitrust laws.

The three patents at issue were 5,549,912, 5,508,042 and 5,656,295. During the application process for those patents, the United States Patent and Trademark Office repeatedly rejected Purdue’s arguments that their new formulation was a significant advance over previous knowledge. Purdue eventually overcame the USPTO’s objections by suggesting that it had clinical trial data showing the drug was surprisingly more effective in controlling pain than scientists would have predicted. Purdue, in fact, had no such results. Its claims were based on the supposed “insight” of one of its experts, without scientific proof.

In making its decision, the Court of Appeals for the Federal Circuit stated that “Purdue made a deliberate decision to withhold and thus misrepresent the origin of its ‘discovery’ to the PTO.” The court did not make a determination as to whether the USPTO relied on Purdue’s misrepresentation in making its decision to allow the patents. Current law does not require the court to make such a finding. However, the Patent Reform Act of 2005 (H.R. 2795) would require that a patentee’s misconduct amounted to fraud before a court could invalidate a patent on that basis. Additionally, it would make the USPTO the sole adjudicator of whether or not the party had committed misconduct.

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