Warner-Lambert and the Pfizer group (Pfizer) successfully appealed to the Full Federal Court to broaden the scope of an interlocutory injunction restraining the supply of Apotex's pregabalin products (Warner-Lambert Company LLC v Apotex Pty Ltd  FCAFC 59). This decision suggests that efforts made by generics companies to restrict the registration of a bioequivalent pharmaceutical product to indications outside that claimed in a patent may be insufficient to avoid interlocutory restraint.
Pfizer supplies pregabalin in Australia under the trade name Lyrica. Lyrica has been registered on the Australian Register of Therapeutic Goods (ARTG) since 2005 for the treatment of neuropathic pain and as an adjunctive therapy in adults with partial seizures. Pfizer holds two relevant patents relating to the use of pregabalin, one directed to methods for treating seizures ("the Seizure Patent") and the other directed to methods of treating pain ("the Pain Patent").
In September 2012, Apotex's pregabalin products were registered on the ARTG with indications for treating neuropathic pain and seizures. The registrations were obtained on the basis that the Apotex products were bioequivalent to Lyrica. In May 2013, Apotex commenced revocation proceedings against the Seizure Patent and the Pain Patent. However, in October 2013 the challenge to the validity of the Seizure Patent was resolved by consent in confidential terms. At approximately the same time, Apotex applied to have their ARTG registration for pregabalin amended to include only the seizure indication.
In response to Apotex's actions, Pfizer sought an interlocutory injunction to restrain Apotex from launching its pregabalin products for the treatment of seizures, claiming that the supply would constitute indirect infringement of Pfizer's Pain Patent.
Significantly, section 117(2)(b) of the Australian Patents Act 1990 states that if the use of a product by a person would infringe a patent, the supply of that product by one person to another is an infringement of the patent by the supplier if .... the supplier had reason to believe that the person would put it to that use.
Section 117(2)(b) was considered in a recent decision of the High Court of Australia in Apotex Pty Ltd v Sanofi-Aventis Australia Pty Ltd  HCA 50 ("the Sanofi decision"). The Sanofi decision suggested that indirect infringement in accordance with section 117(2)(b) might be avoided by obtaining ARTG registration of pharmaceutical products for indications other than those claimed in a patent.
The primary decision
The primary judge granted an injunction restraining Apotex from supplying pregabalin indicated for the treatment of neuropathic pain. Apotex did not oppose this injunction. However, consistent with the Sanofi decision, the primary judge refused an injunction restraining Apotex from supplying any product containing pregabalin indicated only for the treatment of seizures.
In reaching his decision the primary judge concluded that a prima facie case of "reason to believe" that Apotex-Pregabalin would be prescribed for the treatment of pain had not been established.
The Full Court decision
In contrast to the primary decision, the Full Court accepted Pfizer's evidence that there was essentially no market or at least only a very small market for pregabalin in Australia as an anti-seizure medication. The Full Court also accepted evidence that there was a market for the use of pregabalin outside that of neuropathic pain, namely for pain generally and such a use would infringe the Pain Patent.
In an attempt to support their position, Apotex relied on promotional material to be supplied to doctors and pharmacists that stated Apotex-Pregabalin is not indicated for the treatment of neuropathic pain. However, the evidence before the Full Court showed that many doctors who prescribe drugs routinely do so without specifying any indication on the prescription and that pharmacists would not be deterred, by Apotex's promotional material, from substituting Apotex's product because they would know that it was bioequivalent to Pfizer's Lyrica product. Thus, the Full Court held that although the apparent intended use of Apotex-Pregabalin fell outside the method defined in the Pain Patent, there was a prima facie case that Apotex had reason to believe that Apotex-Pregabalin would be used in a manner claimed in the Pain Patent.
The findings of the Full Federal Court contrast with those of the High Court in the Sanofi decision. Thus, it appears that matters relating to the use of a generic bioequivalent product, having a restricted ARTG registration and associated promotional material, need to be considered on a case-by-case basis. The stated use of the bioequivalent product being outside that claimed in a patent may not be sufficient to prevent a patent owner from establishing at least a prima facie case of indirect infringement against the supplier of the bioequivalent product.
The revocation and infringement proceedings in relation to Pfizer's Pain Patent will be heard in October of this year and Shelston IP will keep readers promptly informed of future developments.
The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.