Case:

Apotex Inc. v. Lundbeck Canada Inc., H. Lundbeck A/S and The Minister of Health [A-129-09]

Mylan Pharmaceuticals ULC v. Lundbeck Canada Inc., H. Lundbeck A/S and The Minister of Health [A-135-09]; and Cobalt Pharmaceuticals Inc. v. Lundbeck Canada Inc., H. Lundbeck A/S and The Minister of Health [A-139-09]

DRUG:

escitalopram (CIPRALEX®) Nature of Case:

Appeal from a Prohibition Order under the NOC Regulations Successful Party:

Lundbeck Canada Inc. and H. Lundbeck A/S Date of Decision:

November 25, 2010

Summary:

On November 25, 2010, the Federal Court of Appeal dismissed three related appeals by Apotex Inc. ("Apotex"), Mylan Pharmaceuticals ULC ("Mylan") and Cobalt Pharmaceuticals Inc. ("Cobalt") (collectively "Generics") to set aside prohibition orders that had been issued by the Federal Court in respect of Canadian Patent No. 1,339,452 ("the '452 Patent") and the medicine escitalopram. The Court held that the Applications Judge properly found that the Generics' allegations of invalidity were not justified and that prohibition orders were issued correctly.

The '452 Patent claims escitalopram for use as an antidepressant. Escitalopram is one of two enantiomers of citalopram. It is also known as (+) citalopram or S-citalopram. The '452 Patent states that citalopram (i.e., the racemate) was disclosed in a prior U.S. patent ("the '193 Patent") as part of a general formula covering a few hundred compounds; however, escitalopram was not specifically described or claimed. The inventors also state that precursor of citalopram was disclosed in a prior U.S. patent ("the '884 Patent").

At first instance, the Applications Judge held that the invention claimed in the '452 Patent relates to the two enantiomers of citalopram, including their pharmaceutically acceptable salts and their use as anti-depressants. The Applications Judge held that the '452 Patent was not a selection patent as escitalopram was not disclosed or claimed in the '193 Patent. The Court also held that escitalopram was not anticipated since none of the prior art disclosed this enantiomer or its use as an antidepressant. The Court rejected arguments based on inherent anticipation and also found that the claimed invention was not obvious. The Federal Court decision was the subject of a Pharma in Brief dated March 13, 2009.

On appeal, each of the Generics argued that the '452 Patent is an invalid selection patent and that escitalopram was anticipated by the disclosure of the racemate in the '193 Patent. Some of the Generics argued that the claimed invention was obvious, ambiguous, described insufficiently, and lacking in utility. Each of these arguments was rejected by Noel JA writing for a unanimous court.

The Court of Appeal affirmed the finding at first instance that the '452 Patent is not a selection patent as escitalopram was not described and claimed in the '193 Patent. In particular, Noel JA noted that a claim for a racemate does not automatically include a claim for its enantiomers. Rather, each case must be decided on the "particularities of the patents in issue."

The Court also rejected the Generics' arguments based on anticipation. Noel JA held that escitalopram was not disclosed or enabled by the '193 and '884 Patents for "if the subject-matter of either prior U.S. patent were worked, the result would be a racemate, not an enantiomer." The Court also held that escitalopram was not inherent in the prior disclosure of the racemate as the evidence demonstrated that this enantiomer is not produced in a substantially pure form when administered to humans.

In regard to obviousness, Noel JA held that the Applications Judge applied the law correctly and did not err in his result. The differences between the inventive concept and the state of the art would not have been obvious to a person skilled in the art.

In terms of utility, the Court of Appeal held that the testing of escitalopram in rodents gave the inventors a rational basis for a sound prediction of efficacy in humans as the same tests had been used previously to establish the efficacy of citalopram. The fact that one of the salts encompassed by claim 1 was shown to be toxic did not mean that the invention lacked utility. Noel JA held that "a claim that can only be read one way cannot be altered by reference to the disclosure or specifications. The person skilled in the art aware that some acid addition salts are toxic and that others are not would read claim 1 for what it says, i.e., a claim for substantially pure escitalopram and the acid addition salts thereof that are "non-toxic". The "toxic salt" of escitalopram was effectively excluded from the scope of claim 1.

On the issue of sufficiency, the Court held that invention was described in full, clear and exact terms, as required by the Patent Act. The Court held that the reference to human administration of the drug did not lay a "false trial" and that there was no evidence of an "effort to mislead." The allegations of insufficiency were not justified.

The final issue on appeal related to procedural fairness and the adequacy of reasons. The Court of Appeal held that it would have been preferable for the Applications Judge to issue separate reasons in each of the three applications as the proceedings were not consolidated. However, Noel JA held that "no injustice results from the fact that he issued a single set of reasons." The Court of Appeal held that the reasons for decision were adequate in all other respects and dismissed this ground of appeal.

FCA Decision: Apotex Inc. v. Lundbeck Canada Inc., 2010 FCA 320

FC Decision: Lundbeck Canada Inc. v. Canada (Minister of Health), 2009 FC 146