11 September 2016

Recombinant DNA Technology and Extensions of Patent Term – ‘Swiss-Style’ Claims Continue to Confuse

Swiss-style climb!A recent decision by the Administrative Appeals Tribunal of Australia has addressed the question of whether a patent directed to a second or subsequent medical use of a known pharmaceutical substance can be eligible for an extension of term, in the particular case that the substance is produced using recombinant DNA technology: AbbVie Biotechnology Ltd Commissioner of Patents [2016] AATA 682 (‘AATA decision’).  In deciding that so-called ‘Swiss-style claims’ can support an extension of term (assuming that all other requirements are satisfied), the AATA has reversed the finding of a Delegate of the Commissioner of Patents that such patents are not eligible for term extensions: AbbVie Biotechnology Ltd [2015] APO 45.  (Never fear if you are unfamiliar with the meaning of the terms ‘recombinant DNA technology’ and/or ‘Swiss-style claims’ – I explain further below.)

In Australia, the normal maximum term of a patent, i.e. 20 years from its original filing date, can be extended by up to five years in the case of certain pharmaceutical products, to compensate for the time that is typically required to complete trials and obtain the regulatory approvals necessary to actually commence marketing of a commercial drug.  For an original medical use of a substance, the availability and duration of any extension of term depends upon when a product including the substance is first listed on the Australian Register of Therapeutic Goods (ARTG).  Generally, extensions are available only for patents covering the pharmaceutical substances themselves – patents on methods of making or using the substances are not extendible.  The one exception to this rule relates to the use of recombinant DNA technology in the production of a pharmaceutical substance.

AbbVie Biotechnology Ltd (‘AbbVie’) owns a number of Australian patents relating to a pharmaceutical substance known as adalimumab, which is produced by a process of recombinant DNA technology.  This drug is marketed under the name HUMIRA, and is supplied in the form of an injectable solution for the treatment of a number of diseases.  It was originally approved, and listed on the ARTG on 10 December 2003, for treatment of rheumatoid arthritis.  It was subsequently demonstrated to be effective for the treatment of rheumatoid spondylitis, Crohn’s disease and ulcerative colitis, and these additional indications were added to the ARTG on 10 August 2006, 29 June 2007 and 23 July 2013 respectively.  AbbVie has patents covering these further medical uses of HUMIRA, each of which includes ‘Swiss-style’ claims.

AbbVie applied to the Australian Patent Office to extend the terms of its three further medical use patents.  The Delegate determined that they were not eligible for extensions of term, even if the extension applications had been filed in time (which he found they were not, because the applications should have been based upon the original 2003 listing on the ARTG, not the 2006, 2007 and 213 listings).  On appeal, the AATA reversed the first aspect of the Delegate’s findings, deciding (wrongly, in my view) that Swiss-style claims can form the basis for an extension of patent term.

Recombinant DNA Technology

A recombinant DNA (rDNA) molecule is one that has been artificially created by bringing together genetic material from multiple sources to create gene sequences that are not present in nature.

A particularly well-known medical application of rDNA technology is the production of human insulin for the treatment of diabetes.  By inserting the human insulin gene into a bacterium (such as E. coli) or yeast, the resulting organism becomes a biological insulin factory.  Insulin produced in this way has almost completely replaced the use of insulin from animal sources, such as pigs and cattle.

Thus, rDNA technology can be used as a means to produce better, safer, cheaper and/or more sustainable medications.  As in the case of insulin, the resulting compounds, and their activity, may be old and well-known, but there is nonetheless a clear case for providing patent incentives for companies to invest in research and development of recombinant techniques for production of medications.

Term Extensions for rDNA-Derived Products

Section 70(2) of the Australia Patents Act 1990 provides for two (and only two) circumstances in which a patent relating to a pharmaceutical substance may have its term extended by up to five year, assuming that all other requirements are also satisfied.  These are that:

        (a)  one or more pharmaceutical substances per se must in substance be disclosed in the complete specification of the patent and in substance fall within the scope of the claim or claims of that specification;
        (b)  one or more pharmaceutical substances when produced by a process that involves the use of recombinant DNA technology, must in substance be disclosed in the complete specification of the patent and in substance fall within the scope of the claim or claims of that specification.
With regard to paragraph (a), a Full Bench of the Federal Court of Australia, in Boehringer Ingelheim International GmbH v Commissioner of Patents [2001] FCA 647, consider the legislative history of section 70, and concluded that this condition is limited to (valid) claims directed to particular pharmaceutical substances (at [40]):
... the Explanatory Memorandum says that claims to ‘pharmaceutical substances per se, would usually be restricted to new and inventive substances’. The Explanatory Memorandum excludes the application of the new provisions to ‘new processes of making pharmaceutical substances or new methods of using pharmaceutical substances, where the substances themselves are known’. (Emphasis in original.)
In this context, paragraph (b) provides an exception to this general rule.  Notably, the phrase ‘per se’ does not appear, suggesting that it is not the identity, novelty and inventiveness of the substance itself that is at issue, but the production of the substance using rDNA technology.  On this, the Explanatory Memorandum to the present version of section 70 (cited by the AATA at [68]) stated, immediately following the passage quoted by the Full Court in Boehringer:
Patents that claim pharmaceutical substances when produced by a particular process (product by process claims) will not be eligible unless that process involves the use of recombinant DNA technology.  (Emphasis added.)
Thus, a patent covering a known pharmaceutical substance made by a new process of chemical synthesis will not be eligible for an extension of term, however a patent covering the same substance when made by a process ‘that involves the use’ of rDNA technology may be eligible for an extension of term.
Notably, in two relatively recent decisions, ImmunoGen, Inc. [2014] APO 88 and Novartis Vaccines and Diagnostics S.r.l. [2015] APO 2, the Australian Patent Office determined that the requirement for a process to ‘involve the use of’ rDNA technology is a broad one.  In ImmuoGen it was found to be sufficient that rDNA technology was used as a step in the overall process resulting in an anti-cancer drug, although it was not directly responsible for the production of the final active ingredient.  In Novartis, the final claimed product was a mixture of three proteins produced using rDNA technologies, combined with a fourth antigen and two further additives.  The presence of the three rDNA products was found to be sufficient to satisfy the ‘involves the use’ condition.

So, What About Swiss-Style Claims?

The ‘general’ form of a Swiss-style claim is ‘the use of a compound [X] for the preparation of a medicament [Y] for treatment of a disease/condition [Z]’.  As I have written previously, the primary purpose of such claims is to enable the discovery of new medical uses for known compounds to be rewarded with some form of patent protection, even if patenting methods of medical treatment is prohibited in a particular jurisdiction (although there is no such restriction in Australia).

The proper interpretation and precise scope of Swiss-style claims has been controversial, but until last year had received little judicial consideration in Australia.  Generally, Swiss-style claims are treated as if they cover any and every method of making a medicament of any kind that includes the compound as an active ingredient, and with the intention of it being used to treat the new condition.  The validity of such claims depends upon a ‘legal fiction’ that the required novelty and inventiveness can be attributed to the discovery of the compound’s activity in relation to the new condition, even though there may otherwise be nothing new in manufacturing medicines including the known compound.

In Otsuka Pharmaceutical Co., Ltd v Generic Health Pty Ltd (No 4)[2015] FCA 634, a single judge of the Federal Court of Australia confirmed (at [120]) that ‘an invention defined by a Swiss type claim is appropriately characterised as method or process’ of manufacturing a medicament, and not as a claim to the product itself.

So, should a patent including a Swiss-style claim in which the known compound X happens to be produced by a process involving the use of rDNA technology be eligible for an extension of term?  On the face of it, the claim covers any method of making the medicament Y for treatment of Z and, since X is a product of rDNA technology, on the Patent Office’s own broad interpretation in ImmunoGen and Novatis it would seem logical that Y ‘involves the use of’ rDNA technology in the requisite manner.

However, this was not the view taken by the Delegate of the Commissioner of Patents in this case (APO decision at [13]):

... while notionally directed to a method or process of manufacturing a medicament, the claims are characterised by a therapeutic use. Consequently ... I do not find that a pharmaceutical substance, when produced by a process that involves the use of recombinant DNA technology, in substance falls within the scope of the claims.
The AATA found otherwise (at [71]):
Section 70(2)(b) only refers as a qualification for extension, to the requirement that the substance be produced by recombinant DNA technology. An interpretation which would incorporate into the plain reading of section 70(2)(b) an exclusion of Swiss style claims based upon a substance produced by recombinant DNA technology is unwarranted. The manner in which this subsection has been construed by the delegate overlooks the express requirement which qualifies process claims based upon a substance produced by recombinant DNA technology. No exclusion is incorporated. ... Whilst the Explanatory Memorandum at [9] refers to limiting the use of a known substance to a particular environment, ‘when used in a new and inventive method of treatment’, the legislation does not address such a limitation and does not use terminology to state that ‘Swiss style’ claims are not included in the eligibility for extension. The only requirement, for extension of a patent for a substance produced by recombinant DNA technology, is that it be disclosed in the complete specification of the patent and fall within the scope of the patent. The patents sought to be extended satisfy such criteria.

Did the AATA Get It Right?

As I have already noted above, Swiss-style claims are founded on a legal fiction.  The only reason they are valid, and have any meaning at all, is because we have all agreed to treat them as being valid and meaningful.  If they were read literally, and the normal rules of claim construction applied, they would be invalid on multiple grounds.

For one thing, a typical patent specification including Swiss-style claims does not disclose any new process for making a medicament.  Support for a Swiss-style claim lies in demonstrating that the known pharmaceutical substance is effective for a new therapeutic use.  If the claim were read literally, it would be invalid on the ground that it claimed a manufacturing process without providing a corresponding disclosure in the description.

Additionally, the Swiss-style claim does not claim some specific new and inventive method for making a medicament.  On a conventional interpretation, it claims all possible processes for making all viable medicaments using the identified known pharmaceutical substance, which are suitable for the specified therapeutic use.  Such a claim should also be invalid on the grounds that it is overreaching, and that it is not novel or inventive.  In light of all of these issues, Swiss-style claims are arguably also unclear in their scope (which is the basis upon which the Australian Patent Office used to reject them, up until 1998).

Furthermore, there is no sound policy basis for allowing extensions of patent term based on Swiss-style claims if, and only if, the pharmaceutical substance from which the medicament is manufactured is one whose production involves the user of rDNA technology.  The exception for rDNA-based processes in paragraph 70(2)(b) is designed to reward the development of new rDNA technologies for producing pharmaceuticals, not for discovering new therapeutic uses for substances that already happen to be produced using rDNA techniques.  Swiss-style claims should therefore be treated identically, regardless of whether the basic substance in produced by rDNA techniques, or other means.

For all these reasons, I do not agree with the conclusion of the AATA in this case.  I think that the Commissioner’s Delegate was correct to focus on the fact that Swiss-style claims are characterised by a therapeutic use.

Conclusion – Is There an Appeal in the Offing?

Absent our tacit agreement to the legal fiction that Swiss-style claims are supported by the new and non-obvious discovery of the utility of the pharmaceutical substance for the specified therapeutic use, they would be hopelessly invalid.

It is therefore inconsistent, and only adds to the remaining confusion around Swiss-style claims, for the AATA to decide that they should be interpreted literally for the purposes of paragraph 70(2)(b), when they are so plainly not interpreted literally in every other context.  In deciding that the characterising therapeutic use was the relevant factor in assessing whether or not Swiss-style claims are eligible for term extension, the Delegate was applying a consistent approach and was, in my view, correct to do so.

Ultimately, the AATA still found that the patents could not be extended, because they could only be based on the original listing of HUMIRA on the ARTG, and not upon the dates of addition of the subsequent indications for treatment of rheumatoid spondylitis, Crohn’s disease and ulcerative colitis.  I think that this finding is correct, and consistent with Full Federal Court authority.  Nonetheless, I would not be surprised to see the AATA decision appealed to the Federal Court.  Indeed, the Commissioner of Patents may seek to appeal the AATA finding on the eligibility of Swiss-style claims for term extensions, considering the possibility that other patentees may now seek to take advantage of the decision.


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