Summary Advice

If you have a portfolio of patents which includes an Australian and foreign patent (or application), and you are amending the claims of the foreign patent, careful consideration should be given to possibly amending the Australian claims accordingly.

Background

In the case of Neurim Pharmaceuticals (1991) Ltd v Generic Partners Pty Ltd (No 2) [2019] FCA 154; 139 IPR 424, the granted Australian patent in suit (AU2002326114), entitled “Method for Treating Primary Insomnia”, included (unamended) ‘swiss-style’ and method claims directed to the use of melatonin to improve the restorative quality of sleep in the patient.

The patent owner, Neurim Pharmaceuticals (1991) Ltd. (‘Neurim’) brought an infringement action against Generic Partners Pty Ltd and Apotex Pty Ltd (collectively ‘Generic’). The subject case is an interlocutory application by Neurim to amend the claims of the patent, and opposition thereto by Generic.

At a date after grant of the Australian patent, Neurim amended the claims of corresponding foreign applications to address relevant prior art raised in objections to novelty and inventive step. That prior art had not been raised during examination of the Australian application. The amendments were substantive, and introduced four limitations into claim 1, including limitations to the active compound, the indication, the formulation and the dosage range. Neurim sought leave to similarly amend the Australian claims. Marked claim 1 is shown below:

1. Use of [[at least one compound selected from]] melatonin [[and melatonin agonists,]] in the manufacture of a medicament for treating a patient suffering from primary insomnia characterized by non-restorative sleep and improving the restorative quality of sleep in said patient, wherein said medicament comprises also at least one pharmaceutically acceptable diluent, preservative, antioxidant, solubilizer, emulsifier, adjuvant or carrier, said medicament is a prolonged release formulation in unit dosage form, and said [[at least one compound]] melatonin is present in said medicament in an effective amount within the range of 0.0025 to 510 mg.

The Law

Because Court proceedings in the infringement action had already commenced, Neurim had to request the Court’s leave to amend the claims. Under Section 105(1) of Patents Act 1990 (Cth), the Court has a discretion to determine whether leave should be granted to amend a patent specification. In exercising this discretion, it will not grant leave to amend the patent in a number of circumstances including if the patentee had reasonable grounds to believe that the claim might well be invalid but the patentee delayed taking the necessary steps to amend at that time.

In essence, Neurim would have to persuade the Court that the claims of the Australian patent were valid in the absence of amendment.

The Case for Amendment

Neurim argued for amendment by asserting, inter alia, the following:

• The Australian patent was valid without the amendment.
• The rationale for seeking the amendments in Australia was to narrow the scope of the claims and reduce the scope of the issues in the related infringement proceeding.
• The prior art documents disclosed that melatonin was used to treat lack of sleep quantity, but not to treat lack of sleep quality (being when the patient is asleep, but experiences a poor quality sleep).
• Claims in the corresponding foreign applications had been amended to clarify this difference, and not because of a belief that the claims were otherwise invalid.

The Opposition to Amendment

Generic argued against granting leave to amend the claims by asserting, inter alia, that:

• On a broad interpretation of the claims, they were invalid without the amendment.
• The amendments would narrow the claims and would result in there being a better chance of the Australian patent being found valid.
• Neurim had unjustifiably delayed amending the Australian claims: the same or similar amendments had been made in corresponding applications approximately six years ago, and Neurim had not taken action in Australia in that time.

The Ruling

The guiding principles cited by Nicholas J in this case are expounded by Aldous J in Smith Kline & French Laboratories Ltd v Evans Medical Ltd [1989] 1 FSR 561 at 569:

“The discretion as to whether or not to allow amendment is a wide one and the cases illustrate some principles which are applicable to the present case. First, the onus to establish that amendment should be allowed is upon the patentee and full disclosure must be made of all relevant matters. If there is a failure to disclose all the relevant matters, amendment will be refused. Secondly, amendment will be allowed provided the amendments are permitted under the Act and no circumstances arise which would lead the court to refuse the amendment. Thirdly, it is in the public interest that amendment is sought promptly. Thus, in cases where a patentee delays for an unreasonable period before seeking amendment, it will not be allowed unless the patentee shows reasonable grounds for his delay. Such includes cases where a patentee believed that amendment was not necessary and had reasonable grounds for that belief. Fourthly, a patentee who seeks to obtain an unfair advantage from a patent, which he knows or should have known should be amended, will not be allowed to amend. Such a case is where a patentee threatens an infringer with his unamended patent after he knows or should have known of the need to amend. Fifthly, the court is concerned with the conduct of the patentee and not with the merit of the invention.”

His Honour was persuaded that none of the above limitations applied, and that the proposed amendments should be allowed. Crucially, none of the foreign prosecution histories indicated that the claims would have been invalid in the absence of the amendments.

The Cautionary Tale

It is crucial to maintain tight control over claims in an international patent portfolio. Failure to ensure that claims are amended to ensure validity, even if those claims are already granted, can have serious commercial consequences.

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