Federal Court Affirms Enforceability of OxyContin Patents; Purdue Pharma Did Not Commit Inequitable Conduct, Court Concludes

Stamford, CT – January 7, 2008 – Purdue Pharma L.P. of Stamford, Connecticut achieved an important victory in its patent infringement litigation relating to Purdue’s patents covering the pain medicine OxyContin® (oxycodone HCl controlled-release) Tablets when the United States District Court for the Southern District of New York rejected claims by KV Pharmaceuticals Co, Actavis Totowa L.L.C. and Mallinckrodt, Inc. that the patents in suit were unenforceable because of alleged inequitable conduct by Purdue in obtaining them from the United States Patent and Trademark Office.

In an Opinion and Order dated January 7, 2008, the Court stated, “[T]he weight of the equities before this Court does not warrant the extreme sanction of holding the patents in suit unenforceable. …[D]efendants have failed to show by clear and convincing evidence that Purdue committed inequitable conduct before the PTO, and therefore the patents-in-suit will not be held unenforceable on that basis.”

Purdue Pharma issued the following statement in response to Monday’s action: “We always have maintained that our patents relating to OxyContin were properly issued and therefore are enforceable against infringers. We are therefore gratified by the Court’s ruling.”

The District Court’s ruling arose in infringement lawsuits brought by Purdue against Mallinckrodt, Inc., in 2005 and KV Pharmaceutical Co. and Actavis in early 2007. All three companies are seeking approval from the United States Food and Drug Administration (FDA) to market generic versions of OxyContin.

The ruling resolved an issue left open in the wake of earlier litigation involving the same patents between Purdue Pharma and Endo Pharmaceuticals. In that case, in January 2004, the District Court found that Endo had infringed the Purdue patents but also ruled them unenforceable on the basis of inequitable conduct. In February 2006, the United States Circuit Court of Appeals for the Federal Circuit affirmed the decision with respect to infringement, but vacated the inequitable conduct finding and remanded it for further consideration.

Although Monday’s ruling decided the inequitable conduct claims in Purdue Pharma’s favor, the litigation between the parties has not ended because the defendants have raised other defenses that have not been addressed by the Court.

The professional product labeling for OxyContin® Tablets contains the following boxed warning:

WARNING:

OxyContin is an opioid agonist and a Schedule II controlled substance with an abuse liability similar to morphine.

Oxycodone can be abused in a manner similar to other opioid agonists, legal or illicit. This should be considered when prescribing or dispensing OxyContin in situations where the physician or pharmacist is concerned about an increased risk of misuse, abuse, or diversion.

OxyContin Tablets are a controlled-release oral formulation of oxycodone hydrochloride indicated for the management of moderate to severe pain when a continuous, around-the-clock analgesic is needed for an extended period of time.

OxyContin Tablets are NOT intended for use as a prn analgesic.

OxyContin 60 mg, 80 mg, and 160 mg Tablets, or a single dose greater than 40 mg, ARE FOR USE IN OPIOID-TOLERANT PATIENTS ONLY. A single dose greater than 40 mg, or total daily doses greater than 80 mg, may cause fatal respiratory depression when administered to patients who are not tolerant to the respiratory depressant effects of opioids.

OxyContin TABLETS ARE TO BE SWALLOWED WHOLE AND ARE NOT TO BE BROKEN, CHEWED, OR CRUSHED. TAKING BROKEN, CHEWED, OR CRUSHED OxyContin TABLETS LEADS TO RAPID RELEASE AND ABSORPTION OF A POTENTIALLY FATAL DOSE OF OXYCODONE.

Full prescribing information for OxyContin is available at
http://www.purduepharma.com//PI/Prescription/Oxycontin.pdf.

Contact: Tim Bannon
203-588-8450

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