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Federal Court of Canada Re-examines Test of Obviousness in Patent Law
In the recent Federal Court of Canada decision, Janssen-Ortho Inc v Novopharm Ltd (2006 FC 1234), Justice Hughes examined the validity of the patent for the antimicrobial drug levofloxacin. Only one claim, claim 4 of the patent, was at issue. The defendant (Novopharm) admitted infringement but argued that the patent was invalid. The patent is owned by Daiichi Pharmaceutical Co Ltd (Daiichi) and is licensed to Janssen-Ortho Inc (Janssen). The claim in question claims the S(-) enantiomer of the racemic compound ofloxacin and does not address the medical properties or use of the compound. A racemic compound is a compound that exists in different three-dimensional configurations, known as enantiomers. Janssen markets ofloxacin as FLOXIN, and the S(-) enatiomer levofloxacin as LEVAQUIN. The validity issue was addressed previously in a dispute under the Patented Medicines (Notice of Compliance) Regulations (NOC Regulations) in which the Federal Court found the allegation of invalidity of claim 4 “justified” under section 6(2) of the NOC Regulations. An appeal to the Federal Court of Appeal, heard after the grant of a NOC, was dismissed for being moot, and leave for a further appeal to the Supreme Court of Canada was dismissed. In the current proceedings, Justice Hughes ruled that the earlier finding regarding invalidity in the context of the NOC Regulations, did not constitute a final determination of the question for all purposes. As a result, the current proceedings were taken up with extensive expert testimony that was relevant to Justice Hughes’ task of making a definitive ruling on validity. The court construed claim 4 to mean “S(-) Ofloxacin, different from that contained in the racemate, obtained in a reasonably pure state.” This construction was adopted even though no information regarding purity was found in the patent, because the Court felt such information was unnecessary since the compound was derived using techniques expected to produce a pure compound. Novopharm argued that claim 4 was either anticipated or obvious, due to the previous disclosure of ofloxacin by Daiichi prior to the relevant date and due to the general body of knowledge dealing with methods to separate enantiomers from racemic mixtures. Ofloxacin had been described by Daiichi in a Canadian patent and scientific journal as a racemic mixture with antimicrobial activity. The body of knowledge dealing with separation techniques included two scientific posters displayed at conferences, which explained techniques for the separation of racemic compounds of the same class as ofloxacin. One of these posters was not considered to be prior art by the Court, because it could not have been reasonably known to a person skilled in the art: it was only displayed for a few hours and was never published. The second poster was admittedly viewed by an employee of Daiichi and the information was applied to the separation of ofloxacin to produce the enantiomer claimed in claim 4. Anticipation was argued, because at the relevant date techniques to separate the enantiomers were available, such as those displayed in the posters, and a person skilled in the art would know that one enantiomer of the ofloxacin racemic mixture would have greater activity than the other. The court quickly dismissed this argument since the prior descriptions of ofloxacin did not suggest one enantiomer would have greater activity nor did they describe methods of separation. Thus, no “flag” was planted at the point of the claimed invention. When dealing with obviousness, Justice Hughes commented that the test set out by the Federal Court of Appeal in Beloit Canada Ltd v Valmet OY [8 CPR (3d) 289] comes “perilously close to that for anticipation” and noted that there “would be no point in considering obviousness if it is, in effect, little different than a consideration of anticipation.” Following his comments on the traditional test, Justice Hughes provided a detailed analysis of the appropriate criteria courts should consider in such an investigation. The six major criteria to consider include: (i) the invention as claimed; (ii) the person skilled in the art to whom the patent is addressed; (iii) the body of knowledge a person skilled in the art is expected to have, or have reasonable access to; (iv) the climate in the relevant field; (v) the motivation to solve a recognized problem; and (vi) the effort and time involved in the invention. Also of note, but secondary in importance, are: (vii) the commercial success of the invention; (viii) subsequently recognized advantages; (ix) meritorious awards directed to the invention; and (x) last and least important, hindsight. Justice Hughes than applied these criteria to the case at hand. When considering the body of knowledge, he concluded that at the relevant date the racemic mixture was known and a person skilled in the art would know that the enantiomers would have different properties than the mixture, but they would not know the degree of difference. The climate in the field of medicinal chemistry of was one where few considered the separation of racemic mixtures as a method to produce new active compounds and Daiichi appeared to be the only entity motivated to examine the separation of the enantiomers of ofloxacin. Even though Daiichi used a separation technique laid out in the prior art, it was the first to recognize its utility and apply it to the separation of ofloxacin; thus, the resultant invention was not obvious. Commenting on this conclusion Justice Hughes noted, it is “not the greatest invention, not ‘eureka’, but of sufficient ‘inventive ingenuity’ to merit valid patent protection.” He also noted that this result was not at odds with the finding of invalidity under the NOC Regulations, because the standard of “justification” under those Regulations is somewhat different than that of validity, which is to be determined on the balance of probabilities. The obviousness factors laid down in the case will likely be very influential in future decisions. Mr Justice Hughes was a highly-respected Canadian IP lawyer before his recent appointment to the bench. His decisions in this area of the law will no doubt be watched and followed particularly closely. For the full text of the decision, see: For the earlier decision under the NOC Regulations, visit: decision can be found at: Contact for additional information on the topics discussed within the article above. The contents of this web site are provided for general information purposes only. They are not meant to be legal advice or create a lawyer-client relationship. If you want information or advice relating to your individual circumstances you should consult with your own lawyer or speak to one of the lawyers at Deeth Williams Wall LLP. You may download and print a copy of the material on this site for non-commercial, personal or educational use. Our copyright notice and this disclaimer must remain on all copies. E-TIPS® is a registered trade-mark of Deeth Williams Wall LLP

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