Five Judges speak with one voice on Australian Patent Law Construction and Fair Basis*

The Rosuvastatin case is that rare beast – a decision of a 5 member Full Bench of the Federal Court. It canvases many issues and, no doubt, we shall be picking over it for years to come. Susan Gatford, at the Victorian Bar, has kindly provided a guest post on the section 40 issues. Take it way Sue:

The judgment in AstraZeneca AB v Apotex Pty Ltd [2014] FCAFC 99 is an authoritative statement by a Full Court of the Federal Court of current patent law in Australia on novelty, obviousness, fair basis and indirect infringement. Further, neither the parties nor the Full Court at [37] demurred from the primary judge’s summary of the relevant authorities as to what constitutes common general knowledge and the attributes of the hypothetical skilled addressee. Likewise, neither the parties nor the Full Court at [90] disagreed with the primary judge’s exposition of the principles governing the construction of the claims and body of a specification of a patent.

The Full Court was principally constituted with five justices so as to address issues in regard to obviousness[1]. But the decisions at first instance and on appeal, taken together, also provide a “go to” exposition of most of the legal issues that commonly arise in Australian patent cases.

The Court’s views on the different validity grounds and on indirect infringement each warrant separate commentary and analysis. This article considers one of the construction issues, the decision as to fair basis and the interplay between construction and fair basis.

Background

Statins are a group of drugs that reduce the levels of cholesterol in the blood. Rosuvastatin (marketed in Australia as CRESTOR) is a very successful statin. No patent was ever filed in Australia for the rosuvastatin chemical compound. But AstraZeneca (Az) owns a number of secondary Australian patents relating to rosuvastatin. Two such patents are the subject of the appeal decision. One (the low dose patent) is for the administration of a particular dose or dosage range of rosuvastatin for the treatment of excess cholesterol in the blood stream. The other (the cation patent) is for a pharmaceutical composition (combination) of rosuvastatin mixed with certain inorganic salts.

The Full Federal Court’s decision affirms, although with some differences of reasoning and grounds, Apotex’s victory last year before Justice Jagot, in which it obtained orders revoking both patents.

The outcome of the appeal

The low dose patent was held:

  • to have named the wrong inventor (with a discussion of the current and former entitlement provisions of the Patents Act);
  • to be obvious (with a discussion of the starting point at which obviousness is to be considered and the impact of section 7 of the Patents Act); and
  • not to have been infringed (with a discussion of section 117 of the Patents Act)
  • 

However, reversing the decision of the primary judge, the Full Court held that the low dose patent was novel despite the existence of prior publications disclosing both rosuvastatin and a dosage range that covered the dosage range the subject of the claims.

The cation patent was held:

  • to have impermissibly claimed too early a priority date;
  • to have been anticipated (not novel);
  • to be obvious; and
  • not to be fairly based on the specification (despite the presence of claim 1 as a consistory clause within the body of the specification).

The five judges agreed with each other on all issues. Justices Besanko, Foster, Nicholas and Yates wrote a joint judgment which dealt with all issues except obviousness. Justice Jessup wrote a separate judgment on obviousness with which the rest of the Court agreed.

Patent construction and section 40 issues in relation to the cation patent.

The cation patent was for rosuvastatin mixed with certain multivalent cation inorganic salts. The salts were not therapeutic – their role was said to be simply to stabilize the rosuvastatin and prevent it from degrading. The patent specification described rosuvastatin and various salts being mixed together into a tablet which was then coated.
There was a disagreement between the parties as to the meaning of the words “pharmaceutical composition” in claim 1 of the cation patent. Apotex submitted that in the context of the cation patent “pharmaceutical composition” referred only to the rosuvastatin-salt mixture, and did not include the tablet coating. This was because the proposed Apotex product did not have a rosuvastatin-salt mixture – in its tablet the salt was placed into the coating, not mixed with the rosuvastatin.

Az, in order to maintain its infringement case, argued that the words “pharmaceutical composition” in claim 1 meant the whole tablet i.e. the means by which rosuvastatin is administered or delivered to the patient, whatever form that takes. The primary judge agreed with Az, as did the Full Court.

But, Apotex said, if this is what claim 1 means then it is not fairly based on the specification, as there is no real and reasonably clear disclosure in the specification of a pharmaceutical composition in which the relevant inorganic salt is contained solely within the coating of the pharmaceutical composition and not mixed with the active ingredient, being rosuvastatin. They noted that every disclosure in the cation patent of the use of a relevant salt, including in each of the examples, involved the salt being mixed or blended with rosuvastatin. They also noted that the only theory advanced in the specification to explain how the multivalent cation salt improved the stability of rosuvastatin was that it stabilised its chemical structure, which the experts’ evidence confirmed required “intimate mixing”.

Az did not dispute this evidence but submitted that the fact that claim 1 was repeated in the body of the specification as a consistory clause was itself sufficient for fair basis, relying on statements in Lockwood Security Products Pty Limited v Doric Products Pty Limited (2004) 217 CLR 274 (Doric No 1) at [38] and [91] to [93]. The primary judge had agreed with that submission.

The Full Court, however, disagreed. It said at [421]

“The question that must be addressed is whether there is a real and reasonably clear disclosure in the specification of an invention in which there might be no mixture of the active ingredient and inorganic salt. In our opinion, the specification, when read as a whole, does not make any such disclosure even in the most general sense.”

In other words, the claim was for a composition which contained three things – rosuvastatin, salt and a coating. The claim did not require the salt and the rosuvastatin to be mixed, so the salt could either be with the rosuvastatin or in the coating. In the invention disclosed in the specification, though, the salt and the rosuvastatin were always mixed. The possibility of the salt not being mixed with the rosuvastatin was not contemplated and not disclosed.

Section 40(3) of the Patents Act as applied to this patent (i.e. as it stood before the 2013 amendments to the Patents Act) requires that “the claim or claims must be … fairly based on the matter disclosed in the specification”.

The Court’s finding of lack of fair basis refocuses attention on the construction of claim 1 contended for by Apotex. But the Court was not prepared, in light of the authorities, to read claim 1 as requiring the salt and the rosuvastatin to be mixed, as it considered that to do so would be to draw an impermissible gloss from the specification.

The Court was, however, prepared to use section 40 to strike down what it evidently regarded as a claim that was too widely drawn. Whether the judgment will result in an increase in the number of successful challenges based on section 40 grounds remains to be seen.

AstraZeneca AB v Apotex Pty Ltd [2014] FCAFC 99

 

Thanks, Sue.


  1. As to which see Mark Summerfeild’s recent blog post  ?

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