Avoid Heart Failure – Getting Opposition Procedures Right

The recent decision in Zoetis Services LLC v Boehringer Ingelheim Vetmedica GmbH [2022] APO 72 highlights the importance of strict adherence to procedural matters in patent oppositions.

In Australian patent oppositions there is a strict procedure for the filing of evidence by the parties. The patent opponent firstly files evidence-in-support of the case as outlined in their Statement of Grounds and Particulars. Once the evidence-in-support has been completed the patent applicant has the opportunity to file evidence-in-answer rebutting the evidence-in-support. Finally the patent opponent has an opportunity to file evidence-in-reply addressing the issues raised in the patent applicant’s evidence-in-answer. As such each party gets the opportunity to rebut the substantive evidence tendered by the other side.

In the present case during evidence-in-support the opponent tendered evidence from a veterinarian alleging that he had performed the invention prior to the priority date of the patent under opposition. Unfortunately whilst this allegation was made as part of a statutory declaration there was no physical evidence in the form of contemporaneous records supporting the contention that he had prescribed the drug . The lack of supporting evidence was raised by the patent applicant whose expert witnesses questioned the lack of physical records.

In an attempt to remedy the perceived deficiency, during the evidence-in-reply phase the opponent filed a declaration from a second veterinarian who stated he had also prescribed the drug. This allegation was supported by medical records which included echocardiography reports and discharge instructions.

The patent applicant challenged the admissibility of this evidence on the basis that it was not evidence-in-reply and should not form part of the evidence in the proceedings. After reviewing the authorities on the extent of evidence-in-reply the delegate found that further evidence in relation to the use of the inventions before the priority date of the patent was not properly in reply.

The delegate found that rather than being evidence-in-reply the subsequent declaration was evidence that should have been served as evidence-in-support. Whilst the delegate ultimately allowed the additional evidence due to the public interest in resolving an opposition they did allow the patentee a further opportunity to respond to the further evidence and awarded costs against the opponent in relation to the admissibility of the evidence-in-reply.


Neil is a Principal in the Chemistry and Life Sciences practice group. He has 20 years’ patenting experience across a wide range of chemical technologies, with particular expertise in pharmaceutically active small molecules, polymers and nanotechnology. He specialises in the drafting and prosecution of patent applications in the pharmaceutical and specialty chemicals areas, where he assists clients in obtaining patent protection in Australia and other jurisdictions of interest.