Apotex Inc. v. Sanofi-Sythelabo Canada Inc. et al.What You Need To Know From A Client’s Perspective

by James Ramsbottom

The recent Supreme Court of Canada decision brings forth new developments in Canadian Patent Law jurisprudence. For our clients benefit, we provide a brief summary of the relevant points of the case from a patent prosecution perspective and, for those who wish a more detailed case commentary.

A Selection Patent Is Not Invalid

A selection patent is not invalid, per se, as being anticipated, obvious or as a matter of double patenting.

New Test for Anticipation (Novelty)

Under the new test for anticipation and thus novelty, in Canada, a prior art disclosure must:

  1. Disclose the invention at hand; and
  2. Enable a person of skill in the art to produce the invention without undue experimentation.

Suggested Updated Test for Obviousness

Under an updated test for obviousness in Canada the courts are suggesting that three questions be asked in determining obviousness:

  1. Is it more or less self-evident that what is being tried ought to work?
  2. What is the extent, nature and amount of effort required to achieve the invention?
  3. Is there a motive provided in the prior art to find the solution the patent addresses?
  4. And in cases where advancement in knowledge and thus the state of the art is generally made through experimentation:

  5. Would the invention be “obvious to try”?

Double Patenting

The invention covered by a genus patent is not the same as a selection patent since a claim in the genus patent is broader than in the selection patent.

Detailed Case Commentary

The Supreme Court of Canada has recently handed down its decision in the trial of Apotex Inc. v. Sanofi-Synthelabo Canada Inc. (Sanofi v. Apotex 2008 SCC 61) in rejecting Apotex’s appeal. It has been confirmed by the Supreme Court of Canada that selection patents are not per se invalid. The courts decision appears to bring Canadian jurisprudence more in alignment with that of the United Kingdom and the United States on the issue of obviousness. The court also addresses the long standing test of anticipation.

Briefly, a genus patent was issued to Sanofi, Canadian Patent Number: 1,194,875, (‘875) which disclosed a genus or classes of compounds useful in inhibiting platelet aggregation activity in the blood. The ‘875 genus patent discloses over 250,000 possible different compounds useful for inhibiting platelet aggregation. One of the compounds described is a racemate, meaning that the molecule has a left-handed version or enantiomer and a right-handed version or enantiomer. The racemate is a mix of both the left-handed and the right-handed enantiomers in roughly equal proportions.

Initially, Sanofi attempted to further develop the racemate, however it was a clinical failure due its toxicity. Sanofi’s scientists then separated the racemate after considerable effort into its enantiomers and noted through trials that one of the enantiomers, the right-handed version had improved efficacy and reduced toxicity as compared to the racemate. The left-handed version, however, gave results of significant toxicity and reduced efficacy compared to the racemate. As a result of these discoveries, Sanofi then filed a second subsequent application, the selection patent, which issued to Canadian Patent Number: 1,336,777 (‘777), claiming clopidogrel bisulfate, the right-handed enantiomer of the racemate and a salt of it; now marketed under the trade name of “Plavix.” Clopidogrel is the right-handed enantiomer of the racemate, which was found to have beneficial properties over the racemate disclosed in the ‘875 genus patent.

Apotex charged, in a notice of allegation for obtaining a notice of compliance to market and sell a generic version of Plavix under the patent medicines regulations that it would not infringe Sanofi’s ‘777 selection patent. In suit, Apotex took the position that the‘777 selection patent was anticipated and obvious in light of the ‘875 genus patent. Furthermore, Apotex charged that the ‘777 selection patent was invalid on account of double patenting in light of Sanofi’s prior ‘875 genus patent. The ‘777 selection patent was thus according to Apotex invalid and unenforceable.

Anticipation

On the issue of anticipation, the court found that Sanofi’s ‘777 selection patent was not anticipated by their ‘875 genus patent and developed a new test for anticipation largely based on the courts old test from Beloit v. Valmet Oy (1986).1 Under the old test, anticipation was found if a single prior publication contained all of the information which, for practical purposes, is needed to produce the claimed invention as read by a person skilled in the art without the need for experimentation or the exercise of any inventive skill. The skilled person must in every case and without the possibility of error be led by the publication to the claimed invention. In the case at hand, the Supreme Court of Canada has revised the Canadian test for anticipation to include the requirement of “enablement.” That being said, under the new test for anticipation there is now a two step approach. Firstly, as with the old test, there must be a disclosure. Which in the case at hand, there was a disclosure of the compounds, albeit in the racemate form, in the prior ‘875 genus patent of Sanofi. However, as a second point, the new test adds the requirement of enablement to the test of anticipation. Given that Sanofi itself had to conduct lengthy experiments to separate out the racemate and undergo further trials to determine that the right-handed enantiomer of the compound, named Clopidogrel or Plavix, had increased efficacy and reduced toxicity compared to the racemate, the Court found that the second component of the new test for anticipation had not been met. That being the ‘875 genus patent did not disclose or teach, nor would a person of skill in the art have come without difficulty to the solution of separating the racemate into enantiomers and that the right-handed enantiomer would have increased efficacy and reduced toxicity. There was no enabling disclosure of Clopidogrel as a platelet aggregation inhibitor in the ‘875genus patent and thus it did not anticipate the ‘777 selection patent.

What does this mean for Anticipation?

Under the new test for anticipation and thus novelty, in Canada a prior art disclosure must:

  1. Disclose the invention at hand; and
  2. Enable a person of skill in the art to produce the invention without undue experimentation.

Obviousness

With respect to the issue of obviousness, the Court found that Sanofi’s ‘777 selection patent was not obvious in light of the prior ‘875 genus patent. In Beloit v. Valmet Oy (1986),2 the court stated that:

“…the test for obviousness is not to ask what competent inventors did or would have done to solve the problem. Inventors are by definition inventive…the question to ask is whether a man in the Clapham omnibus of patent law, would in the light of the state of the art and of common general knowledge as at the claimed date of the invention, have come directly and without difficulty to the solution taught by the patent. That is a very difficult test to satisfy.”

The Court asked three questions under the seemingly clairvoyant test for obviousness of Beloit.

  1. Is it more or less self-evident that what is being tried ought to work? Are there a finite number of identified predictable solutions known to persons skilled in the art?
  2. What is the extent, nature and amount of effort required to achieve the invention? Are routine trials carried out or is the experimentation prolonged and arduous, such that the trials would not be considered routine?
  3. Is there a motive provided in the prior art to find the solution the patent addresses?
  4. The Court in addressing these three questions found that there was no reason that a person skilled in the art would have thought that the right-handed enantiomer would have increased efficacy and reduced toxicity over the left-handed enantiomer upon separation of the racemate. Thus, the right-handed enantiomer salt was not obvious. Furthermore, the amount of effort put into separating the enantiomers and testing was a long arduous process that took more than 5 months to complete. Therefore, the trial was not considered to be routine. And lastly, the ‘875 genus patent did not provide a specific motivation or suggestion for one skilled in the art to pursue experimentation with the right-handed enantiomer. The court therefore found that the ‘777 selection patent was not obvious in light of the ‘875 genus patent.

    However, the court in this case introduces a potential fourth question to be asked in the case of selection patents or in cases where advances in the art are generally found through experimentation:

  5. Would the invention be “obvious to try”?

In answering this question the courts have put forth that: “would what is being tried in the patent have been obvious based on the state of the art and that the solution taught by the patent ought to have worked?” In the case of the ‘777 selection patent the Court found that, at the time, the knowledge of persons skilled in the art was not sufficient to make it more or less self-evident to try the right-handed enantiomer and that it ought to work.

The Court, thus, found the ‘777 selection patent to be non-obvious.

What does this mean for Obviousness?

Under an updated test for obviousness in Canada the courts are suggesting that three questions be asked in determining obviousness:

  1. Is it more or less self-evident that what is being tried ought to work?
  2. What is the extent, nature and amount of effort required to achieve the invention?
  3. Is there a motive provided in the prior art to find the solution the patent addresses?
  4. And in cases where advancement in knowledge and thus the state of art is generally made through experimentation:

  5. Would the invention be “obvious to try”?

This decision relating to obviousness brings Canadian jurisprudence more into alignment with the 2007 KSR v. Teleflex case decided before the U.S. Supreme Court in that one must “consider everything”. If this approach to consider everything leads to the anticipated success, it is likely that the product is not of innovation, but of common sense and ordinary skill.

Double Patenting

On the issue of double-patenting, the court found that since a selection patent may be sought by anyone, including the inventor or owner of the original genus patent, evergreening (extending the monopoly through a second patent) is not a concern. The invention covered by a genus patent is not the same as in a selection patent since a claim in the genus patent is broader than in the selection patent. The selection patent covers a specific drug, where as the genus patent covers a broad class of compounds.

[1] Beloit Canada Ltd. v. Valmet Oy (1986), 8 C.P.R. (3d) 289 (F.C.A.) at 297.

[2] Beloit Canada Ltd. v. Valmet Oy (1986), 8 C.P.R. (3d) 289 (F.C.A.) at 294.