CSL Limited and Monash University, the applicants, are the proprietors of an Australian patent in respect of an invention for a stabilised growth hormone and a method of preparation thereof. The applicants issued infringement proceedings against Novo Nordisk Pharmaceuticals Pty Ltd and other members of the Novo Nordisk group. The respondents cross-claimed for a declaration of invalidity and patent revocation on the grounds that it lacked an inventive step and that the invention was not novel.
The applicants sought to amend the patent by inserting a statement into Claim 1 of the patent that specified the pH of the formulation, and to remove broad pH requirements from Claim 7.
Jessup J noted that “[i]t appears that this step was taken at least substantially to make the applicants the better able to resist the respondents’ case on validity”. Whilst the amendments were allowable amendments under the Patents Act, this judgment dealt with the judicial discretion to amend the patent.
The Court upheld and applied the principles referred to in the judgment of Aldous J in Smith Kline and French Laboratories Ltd v Evans Medical Ltd  1 FR 561, specifically paragraph 569, which provides:
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.
The respondents argued that the applicants had not been upfront about their reason to amend the patent, had unreasonably delayed seeking amendment and had sought to obtain an unfair advantage by issuing proceedings on the unamended patent.
Jessup J refined Aldous J’s principles with regard to full disclosure and seeking an unfair advantage, stating that if documents that disclose relevant matters arise “as a result of the forensic process itself”, rather than raised by the parties themselves, then the Court should not interpret this as inadequate disclosure but rather proceed to assess the application. Jessup J found that
[t]o the applicants’ actual or constructive knowledge, serious and apparently legitimate issues had been raised elsewhere which had the potential to undermine the validity of the relevant claims in the patent. It was, in my view, strongly in the public interest that those issues be confronted in the Australian context. It was not in the public interest that they be ignored, and that proceedings be commenced on the silent premise that they did not exist.
Jessup J refused the proposed amendments.