Patent extensions and the requirement for a pharmaceutical substance per se
In brief: Allens Articled Clerk Martin Hecht and Partner Michael Dowling (view CV) review current issues in the pharmaceutical patent area
In brief
A recent trial of two separate proceedings in the Federal Court before Justice Weinberg has canvassed issues regarding when a patent extension can be validly granted. The main points at issue were the meaning of 'pharmaceutical substance' and 'pharmaceutical substance per se' and, whether judicial review of the grant of the patent extension was available. Resolution of these matters awaits the decision.
Background
Two proceedings, Pharmacia Italia SpA and Pfizer Perth Pty Ltd v Mayne Pharma Pty Ltd, F H Faulding & Co Ltd and Faulding Healthcare Pty Ltd (the Mayne Proceeding) and Interpharma Pty Ltd v The Commissioner of Patents and Pharmacia Italia SpA (the Interpharma Proceeding) were heard on 7 and 8 February 2006 in the Federal Court before Justice Weinberg (a third proceeding to be heard was settled by consent at the start of the trial). The proceedings raised overlapping issues relating to the meaning of 'pharmaceutical substance per se' and the grant of a patent extension.
The patent in suit was Australian Patent No 598197 (the Patent) in the name of Pharmacia Italia SpA (Pharmacia) .
Claim 1 of the Patent is a claim to:
A sterile, pyrogen-free anthracycline glycoside solution which comprises a physiologically acceptable salt of anthracycline glycoside dissolved in a physiologically acceptable aqueous solution therefor at an anthracycline glycoside concentration of from 0.1 to 50mg/ml, which has not been reconstituted from a lyophilizate and the pH of which has been adjusted from 2.5 to 5.0 solely with a physiologically acceptable acid.
Anthracycline glycosides are a class of well known cytotoxic drugs. Prior to the Patent, these drugs had not been available in a ready-to-use solution form but rather as a powder which had to be put into solution prior to administration.
The original term of the Patent was for 20 years ending on 19 June 2006. In 2002 the Commissioner of Patents (the Commissioner) granted an extension to the Patent to 19 June 2011.
An injunction, to expire on 19 June 2006, had previously been granted against Mayne in the Mayne Proceeding. At issue was whether the injunction should be extended to 19 June 2011. Mayne's submissions included that, under section 78 of the Patents Act 1990 (Cth) (Patents Act) it would not infringe the Patent during the extended term of the Patent (for the reasons stated below) and, as such, the injunction should not be extended.
The Interpharma Proceeding is an application for judicial review under the Administrative Decisions (Judicial Review) Act 1977 (Cth), the prerogative writs and section 192 of the Patents Act of the decision by the Commissioner to grant the extension of term . Interpharma argued that, amongst other things, subsection 70(2)(a) of the Patents Act had not been satisfied and therefore the extension had been invalidly granted. Section 192 provides that a person aggrieved by an omission in the Register, an entry made without sufficient cause, an entry wrongly existing, or an error or defect in an entry in the Register, may apply for an order to rectify the Register. Interestingly, the limits of section 192 have not previously been the subject of judicial consideration.
Extension legislation
An extension of up to five years can be granted for pharmaceutical patents in Australia.
For an extension of term to be valid, there must be compliance with sections 70 and 71 of the Patents Act. Subsection 70(2)(a) requires that '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'. Subsection 70(3)(a) requires that 'goods containing, or consisting of, the substance must be included in the Australian Register of Therapeutic Goods'.
Section 78 of the Patents Act restricts the rights of the patentee during the extended term of a patent. Subsection 78(1)(b)(i) states that, during the extended term of a patent, the patent will not be infringed by a person exploiting any form of the invention other than 'a pharmaceutical substance per se that is in substance disclosed in the complete specification of the patent and in substance falls within the scope of the claim or claims of that specification'. Therefore, if the Patent does not in substance disclose and claim a pharmaceutical substance per se, Mayne would not infringe during the extended term of the Patent.
Pharmaceutical substance
The Patents Act defines a pharmaceutical substance as:
a substance (including a mixture or compound of substances) for therapeutic use whose application (or one of whose applications) involves:but does not include a substance that is solely for use in in vitro diagnosis or in vitro testing.
- a chemical interaction, or physico-chemical interaction, with a human physiological system; or
- action on an infectious agent, or on a toxin or other poison, in a human body;
Interpharma argued that a 'pharmaceutical substance' is restricted to a single active ingredient, or a mixture (or compound) of active ingredients.
Pharmacia contended that the solution as a whole (ie the active pharmaceutical ingredient plus excipients) was the pharmaceutical substance, as it was a mixture of substances which was injected into a patient to give rise to the desired therapeutic effect.
A pharmaceutical substance per se
Two earlier Federal Court cases have dealt with the question of what is a pharmaceutical substance per se1. Boehringer involved a patent for a container with a nozzle for delivering an aerosol or spray composition for nasal administration, while the patent in Prejay was for a method of treating menopausal women using a transdermal patch to provide continuous dosages of progesterone and estrogen. In both cases the court found that the patents did not disclose or claim a pharmaceutical substance per se.
At issue in the Mayne and Interpharma Proceedings was whether the Patent disclosed or claimed a pharmaceutical substance per se. This issue centred around whether elements of claim 1 of the Patent were attributes of the solution claimed or process elements.
Conclusion
We await a decision from Justice Weinberg on the patent term extension issues. Furthermore, it will be interesting whether the Interpharma proceeding will provide an indication of the limits of section 192 of the Patents Act. We will report again when the decision is published later this year.
Footnotes
- Boehringer Ingelheim International GmbH v Cmr of Patents (2001) 112 FCR 595 (Boehringer) and Prejay Holdings Ltd v Commissioner of Patents (2003) 57 IPR 424 (Prejay).