15 July 2005
Key Points:
The Federal Court's first application of the High Court and House of Lords' most recent patent decisions to pharmaceutical patents in Australia.
In April 2005, the Federal Court (per Justice Merkel) handed down judgment in PhotoCure ASA v Queen's University at Kingston [2005] FCA 344 . This case provides a comprehensive review of many of the general principles of both patent validity and infringement in Australia and how those principles are applied in the context of pharmaceutical patents. It is also the first Federal Court case to apply the principles set out by the recent High Court case of Lockwood Security Products Pty Ltd v Doric Products Pty Ltd (2004) 212 ALR 1 (concerning fair basis) and the House of Lords' decision in Kirin-Amgen Inc & Ors v Hoechst Marion Roussel Ltd and Transkaryotic Therapies Inc [2005] 1 All ER 667 ("Amgen v TKT") concerning construction of a patent's claims to determine infringement (which we look at here).This article will focus on the Court's application of those decisions to the case before it.
Background
PhotoCure concerned a patent registered by Queen's University at Kingston and assigned to DUSA Pharmaceuticals Inc, the second respondent in the proceedings. The patent was for an invention entitled "Method of Detection and Treatment of Malignant and Non-Malignant Lesions by Photochemotherapy". The invention involves the use of photodetection and photodynamic therapy ("PDT") for the treatment of certain cancers and lesions. PDT involves the interaction of photons of light with molecules of a photosensitiser. This interaction can be used to kill cells, thus treating cancer. The patent in this case concerned the use of 5-aminolevulinic acid ("ALA"). ALA is not itself a photosensitiser. Instead, the addition of ALA can increase the generation and selective accumulation of protoporphyrin IX ("PpIX"), a photosensitiser, in cells. This increases the effectiveness of PpIX as a photosensitiser, and thus its effectiveness as a treatment for cancer and lesions.
PhotoCure subsequently began to manufacture a drug called "Metvix" which it supplied in Australia. The active ingredient in Metvix is methyl-ALA, a methyl ester of ALA. After methyl-ALA is administered to the patient and reaches the targeted cell, it decomposes by hydrolysis to form separate methyl and ALA ions. The ALA ions then lead to a build up of PpIX. Like DUSA, Metvix sought to use this increased production of PpIX in a form of PDT (the "Metvix Photodynamic Therapy").
PhotoCure applied to the Federal Court for revocation of the patent on the grounds of invalidity. DUSA cross-claimed for declaratory and injunctive relief, claiming that the exploitation and supply by PhotoCure of Metvix in Australia and its proposed use in Australia of Metvix Photodynamic Therapy infringed its patent. These claims, therefore, required the court to consider the principles of both validity and infringement.
Validity
PhotoCure claimed that DUSA's patent was invalid under the Patent Act 1990 for five reasons:
As set out above, each claim was addressed separately and comprehensively by the Court. This paper will discuss only one of these, fair basis.
Fair basis
Section 40(3) of the Act requires that the claims in a patent "must be clear and succinct and fairly based on the matter described in the specification". A consideration of fair basis involves a comparison between the scope of the claim or claims that are challenged, and the description of the invention that is provided in the specification pursuant to section 40(2)(a). This issue of fair basis came before the High Court last year in Lockwood. PhotoCure is the first case to consider the application of Lockwood to the pharmaceutical industry.
PhotoCure argued that the claims should not travel beyond the disclosure set out in the examples and, to the extent that they did, they lacked fair basis and were invalid. The patent in question contained five examples. Three of them related to the treatment of squamous cell carcinomas in the skin by the topical application of ALA, one the treatment of basal cell carcinomas in the skin by the topical application of ALA, and one the injection of ALA in mice. The specification was broader than these examples, dealing with types of lesions other than squamous and basal cell carcinomas.
The High Court in Lockwood made clear that the specification must be considered as a whole to ascertain what it discloses as the invention. Relying on Lockwood, the Court held that it would therefore be incorrect to restrict consideration of the specification's disclosures to what was contained in the examples.
In light of Lockwood, PhotoCure's argument could only succeed if the examples were the only real and reasonably clear disclosure in the specification. The Court regarded this claim as difficult to maintain because in Lockwood, the High Court observed that a claim can be fairly based on nothing more than a use of the same words in the specification, provided that those words reflected the disclosure provided in the specification when read as a whole.
Finally, PhotoCure argued that much of the specification outside of the examples was no more than speculation. Again, the Court rejected this argument, relying primarily upon the Full Federal Court's judgment in Bristol-Myers Squibb Company v FH Faulding & Co Ltd (2000) 97 FCR 524, which in turn approved Justice Lehane's judgment in Aktiebolaget Hässle v Alphapharm Pty Ltd (1999) 44 IPR 593 in which he concluded that:
"The authorities do not, in my view, support a proposition that a claim will be fairly based on a specification only if every way of performing the invention, within the terms of the claim, will produce the result claimed in the invention. There may be questions of degree; but it cannot be right that a claim of the patent in suit would be fairly based only if it claimed particular compounds, particular quantities and particular combinations which the specification disclosed as effective to produce (to some extent, though not necessarily the extent achieved by the inventor's best method) the purpose of the invention."
The Court, therefore, concluded that all the claims in the patent were fairly based upon the specification.
DUSA also succeeded in defending the challenges to the validity of their patent on each of the other four bases referred to above.
Infringement
DUSA was not so successful on their cross-claim for infringement. DUSA claimed that in manufacturing "Metvix" and proposing its use in "Metvix Photodynamic Therapy", PhotoCure was infringing its patent.
DUSA made two alternative submissions regarding infringement. It argued that Metvix Photodynamic Therapy infringed the patent because it fell within the textual meaning of the patent's claims but, that if it fell outside the textual meaning, it nonetheless fell within the substance of the claims.
The Court referred to Lord Diplock's famous statement in Catnic Components Limited v Hill & Smith Limited [1982] RPC 183, in which he found that it was incorrect to treat textual infringement and infringement of substance as separate causes of action, and concluded that while DUSA's submissions on textual and substantive infringement were put in the alternative, they related to the same question of whether the claims, interpreted with a view to their purpose, had been infringed.
Nevertheless, the Court concluded that there was some utility in separately considering the two limbs, deciding that in the present case it would be helpful to determine the primary meaning of the words used in the relevant claims and then to determine if that meaning was displaced by applying the "substance" approach.
Rules to assist construction of the claims
Before undertaking a textual construction of the claims, the Court set out a number of rules to assist. These are:
On the basis of these rules of construction, the Court found that PhotoCure's activities did not infringe DUSA's patent.
The essential point was that the claims that DUSA alleged that PhotoCure was infringing all involved "administering to the patient". Based on both the common meaning of the term "administer" and the use of other terms in the patent, the Court concluded that this was limited to external administration to a patient, and did not include the introduction of that substance into particular cells or lesions. The patent described the latter process as the "provision" of the substance, rather than the "administration" of that substance. From this, the Court concluded that there was no textual infringement.
There was also an issue as to the meaning of "5-aminolevulinic acid". DUSA claimed that the term "5-aminolevulinic acid" extended to related chemical compounds, and that as the active compound in Metvix was a methyl ester of 5-aminolevulinic acid, PhotoCure were infringing the patent. Again, the Court rejected this argument, finding that in the context it was used, the term 5-aminolevulinic acid was very specific and did not extend to related chemical compounds, providing a further basis for a finding that there was no textual infringement.
Court's consideration of infringement in substance
The Court's consideration of infringement in substance is probably the most interesting aspect of this case overall. The Court's starting point was to consider a series of questions known as the Improver questions (discussed here [link to Oh my Lord!]), as the parties disagreed on the law to be applied in ascertaining whether there had been an infringement in substance. While Photocure relied on the Improver questions, DUSA argued that these questions did not reflect the law in Australia as they had been formulated for the purpose of assisting UK courts in applying the Protocol on Interpretation of Article 69 on the European Patent Convention ("EPC"). The Court accepted that it was correct that these questions had certainly been formulated against the background of the EPC, but noted that some Australian decisions had relied upon the Improver questions while others had made no reference to them.
The Court then considered a line of Australian authority discussing both Catnic and Improver, concluding that the Improver questions were no more than an application of the principles in Catnic to the claims in issue in Improver. They were therefore not merely an expression of the European Protocol. After reaching this conclusion on the basis of Australian authority, the Court turned to the House of Lords' decision in Amgen v TKT , which also considered the application of these questions. This is the first time that an Australian court has considered the House of Lords' judgment.
The leading judgment in the House of Lords' decision was written by Lord Hoffman, the same judge who a decade earlier had set out the Improver questions. That judgment confirms that the Improver questions are consistent with the Catnic principles, and so in the Court's view, confirmed its conclusions based on Australian authorities.
Lord Hoffman in Amgen v TKT also held that the Improver questions should not be regarded as legal rules, but rather "guides which will in appropriate cases help to decide what the skilled man would have understood the patentee to mean." The PhotoCure Court agreed with this holding as to the role of the Improver questions, but nevertheless regarded this case as an appropriate one in which to apply those questions.
With regard to the first improver question, "Does the variant have a material effect upon the way the invention works?", the Court said no. In this case, the variant was the administration to the patient of the methyl ester of ALA which is later transformed into ALA by hydrolysis. The only differences in operation between Metvix and the patented invention were quantitative questions, relating to matters such as a different cellular uptake, rather than qualitative differences. In these circumstances, the Court found that there was no material difference in the way that the inventions worked.
Under the Improver questions, this meant that the second question, "Would this have been obvious at the date of publication of the patent to a reader skilled in the art?" should be asked. Ultimately, the Court concluded that it would not have been obvious at the date of the publication of the patent to a person skilled in the art that the use of methyl-ALA instead of ALA would have no material effect on the way that the invention worked. While DUSA presented evidence of some articles showing theoretical views that the operation of the two may be the same, the Court held that these articles were insufficient to establish that the variant would have been obvious at the date of the patent.
On this basis, under the Improver questions, there was no infringement. It was thus not necessary for the Court to consider the third Improver question.
Conclusion
PhotoCure is a useful summary of many important points of Australian patent law. It also shows the application of several recent decisions to pharmaceutical patents in Australia, namely the High Court's Lockwood decision, and the House of Lords' decision in Amgen v TKT. Justice Merkel found that the House of Lords' judgment was consistent with his conclusions, and therefore made no alteration to Australian law as he perceived it. However, given that the House of Lords' decision concerns the operation of the Improver questions, and the applicability of those questions in Australia is far from a settled issue, other judges may take different approaches. It remains to be seen if other judges will follow Justice Merkel's lead in this regard. Until such decisions are handed down, his judgment remains the leading authority in Australia on the operation of the House of Lords' decision in Australia.
