In Purdue Pharma v. Attorney General of Canada and Minister of Health, 2010 FC 738, an application for a judicial review of a decision made by the Office of Patented Medicines and Liaison (“OPML”), the Federal Court found that Purdue Pharma (“Purdue”) was not entitled to list a patent for oxycodone on Health Canada’s Patent Register in respect of its TARGIN oxycodone/naloxone combination product. The OPML had determined that none of the claims of Canadian Patent 2,098,738 (the “738 Patent”) claimed Purdue’s TARGIN oxycodone/naloxone combination product, contrary to section 4(2)(c) of the Patented Medicines (Notice of Compliance) Regulations, SOR/93-133 (“Regulations”). Justice Crampton upheld the OPML decision refusing to list the 738 Patent on the Patent Register, and dismissed Purdue’s application for judicial review.  

OPML REVIEW

The 738 Patent is directed to a controlled-release system for delivering oxycodone and its salts. The 738 Patent contains 28 claims; however, only claims 3 and 5 were at issue before the OPML. Claim 3 claims a controlled release oxycodone formulation for oral administration in humans comprising about 10 to about 40 mg of oxycodone (or its salt) resulting in a specified pharmacokinetic profile. Claim 5 claims a solid controlled release oral dosage form comprising about 10 to about 160 mg of oxycodone (or its salt), an effective amount of a controlled release matrix and a suitable amount of diluent, such that a specified pharmacokinetic profile is achieved. None of the claims mention naloxone.  

In June 2009, the OPML advised Purdue that the 738 Patent was ineligible for listing in respect of TARGIN, because the requirements of sections 4(2)(b) and (c) of the Regulations were not met. Sections 4(2)(b) and (c) establish requirements for listing a patent based on the existence of a claim or claims to a formulation containing a medicinal ingredient or a dosage form of a drug or drug formulation containing the medicinal ingredient, respectively. In August 2009, Purdue submitted that the presence of additional ingredients such as undisclosed excipients or another active ingredient, such as naloxone, would not cause the formulation to fall outside the scope of claims 3 and 5.  

WHAT DOSAGE FORM IS CLAIMED BY THE 738 PATENT?

In the judicial review of the OPML’s decision not to list the 738 Patent in respect of TARGIN, Purdue only asserted claim 5. Purdue submitted that the presence of naloxone in TARGIN did not change the fact that the TARGIN dosage form fell within the scope of claim 5 of the 738 Patent. Purdue argued that the OPML interpretation of claim 5 results in a construction of claim 5 that was contrary to the direction of the Supreme Court of Canada in Whirlpool Corp. v. Camco Inc., 2000 SCC 67. Justice Crampton disagreed, and held that patent construction for the purposes of s.4 of the Regulations is unique and that to be tied to the same construction as used for patent claim invalidity and infringement would undermine the specificity objective of the 2006 amendments to the Regulations. Consequently, the Court construed claim 5 to relate to a dosage form containing oxycodone or its salt as the sole medicinal ingredient.  

DOES THE APPROVED DOSAGE FORM FALL WITHIN THE SCOPE OF THE 738 PATENT?

Purdue submitted that with respect to claims for a dosage form under section 4(2)(c) all that was required was that the dosage form be approved. Purdue suggested that the text of section 4(2)(c) had no requirement relating to the medicinal ingredient. The Court disagreed citing the section 2 definition for “claim for the dosage form” in which there was a requirement relating to the medicinal ingredient. Combined with the principle of specificity that was the hallmark of the 2006 amendments to the Regulations, section 4(2)(c) and section 2 required more than the fact that a dosage form had been approved. Under section 33(2) of the Interpretation Act a singular form is a plural form and a plural form is a singular form, i.e., “medicinal ingredient” and “that medicinal ingredient” also means “medicinal ingredients” and “those medicinal ingredients,” respectively.

Thus, the Court concluded that claim 5 of the 738 Patent claimed a “delivery system for administering a formulation containing oxycodone as the sole medicinal ingredient” and for the purposes of the Regulations the medicinal ingredient naloxone was not within the scope of claim 5. The Court also concluded that the approved dosage form of TARGIN was a delivery system for administering a formulation containing two medicinal ingredients: oxycodone and naloxone. Therefore, for the purposes of the Regulations the two dosage forms were different and the 738 Patent was not eligible to be listed on the Patent Register in respect of TARGIN.

On August 6, 2010, Purdue appealed this decision to the Federal Court of Appeal (A-288-10).