One reason for filing an amendment during prosecution of an Australian patent application to include a proviso (also referred to as a “disclaimer”, or a “negative claim” limitation) is typically for distinguishing an invention from the prior art that falls within the scope of the invention.

Under Australian practice, adding a proviso that simply limits the scope of a claim is allowable, even where the subject matter dealt with in the proviso was not itself disclosed in the specification as filed, providing that the proviso is not added in a manner that adds to the disclosure.

However, such a proviso is not allowable if the amendment would result in the specification claiming or disclosing matter that would “extend beyond” that disclosed in the specification as filed.^[1] Matter is considered to “extend beyond” the original disclosure if the person skilled in the art (PSA) could not directly derive the matter from what is explicitly or implicitly disclosed in the “complete specification as filed”.^[2] 

There are a number of “specific circumstances”^[3] that Examiners are to consider when assessing the allowability of amendments, such as whether:

• an amendment removes or introduces ambiguity;
• adding further embodiments is inconsistent with the specific integers/examples disclosed;
• the amendment is an “intermediate generalisation”;^[4] or
• inserting (or amending) a proviso introduces new subject matter.

Thus, the main test for determining if an amendment is allowable is whether the PSA is being presented with any new information about the invention which is not directly and unambiguously apparent from the original disclosure.

In BioNTech RNA Pharmaceuticals GmbH v CureVac SE,^[5] the case focused on whether amendments proposed during opposition proceedings were allowable, or if they would extend beyond the specification as filed.

The patent in suit relates to RNA-containing compositions for use in the treatment or prophylaxis of tumour and/or cancer diseases, and the claims as accepted were directed to a method of using compositions containing mRNA encoding interleukin-12 (a cytokine).

The Applicant (CureVac SE) proposed the amendments to address particular issues raised in dispute in the opposition, in which claim 1 was amended to clarify that the at least one coding RNA is “not a replicon RNA”, and new claims 36 and 40 were introduced to clarify that the at least one coding RNA is “not a viral RNA or a retroviral RNA”.

In their arguments, the Opponent asserted that there was no basis in the specification as filed for the “negative limitations” introduced by the amendments, and as a consequence, the amendments resulted in subject matter that extended beyond that disclosed in the specification as filed.^[6]

In support, the Opponent referred to certain passages in the specification that indicate that the coding RNA can be selected from the group of mRNA, viral RNA, retroviral RNA and replicon RNA, which makes it clear that the coding RNA of the claims can be replicon RNA. The Opponent then went on to argue that there was no basis in the specification for the “negative limitations” in the amendments that a replicon RNA should be avoided. The Opponent’s expert also noted that the specification taught that the different coding RNA are interchangeable, and therefore it made no sense to him to exclude replicon RNA from the claimed composition.

Recognising that the concept of “intermediate generalisation” was at the heart of the opposition, the Hearing Officer sought guidance from principles drawn from several UK decisions to surmise that an impermissible intermediate generalisation results when an amendment is not allowable if different embodiments of a specification disclose different features, and that it would not have been apparent to the PSA that the features of these different embodiments could be interchanged and were more generally applicable^[7] – see here).

The Applicant acknowledged that the specification as filed made it clear that the coding RNA can be replicon RNA, but then contended that as the specification does not state that it should or must be a replicon RNA, the amendment was merely proposed to clarify the scope of the invention, rather than to introduce a defined feature having a technical significance.

In support, the Applicant referred to Boehringer Ingelheim Animal Health USA Inc v Elanco New Zealand,^[8] where an amendment was made to a claim defining a class of antiseptics to include the proviso “wherein the antiseptic is not an acridine”. In that case, the amendment was found to be allowable because the specification did not indicate a preference for acridine antiseptics. And, as there was no positive recommendation to use acridines, there was no inconsistency between the specification and the amended claims.

Following this line of reasoning, the Applicant asserted in this matter that there was no positive recommendation in the specification to use a replicon RNA or a viral RNA or retroviral RNA, and therefore the amendment was allowable.

The Hearing Officer agreed with the Applicant, asserting that while the specification clearly defines that the coding RNA is to include replicon RNA, it is only the at least one coding RNA of the composition. In other words, there would be other coding RNAs in the composition that do not change the broader definition of the term “coding RNA” as presented in the specification as filed.

In this respect, the amendment was not considered by the Hearing Officer to constitute an impermissible intermediate generalisation, as the claim as proposed to be amended did not teach anything that the PSA would not have gleaned from the specification as filed, even though there was no explicit disclosure in the specification that corresponded to the wording of the amendments.

In short, the Opponent was unsuccessful on all grounds, and the proposed amendments made by the Applicant were subsequently allowed.

Closing comments

To summarise, amending an Australian patent application to include a proviso that limits the scope of a claim is allowable, even in situations where the subject matter dealt with in the proviso was not itself disclosed in the specification as filed, provided that the proviso is not added in a manner that adds to the disclosure.

While adding a proviso that draws on different features disclosed in different embodiments of the specification is not allowable if it would not have been apparent to the PSA that the features of these different embodiments could be interchanged.

References

[1] s102(1) of the Patents Act 1990 (Cth) (the Act), as applicable to standard and innovation patents for which examination was or is requested after 15 April 2013 (when the “Raising the Bar” amendments took effect).

[2] Other prescribed documents that are relevant for the purpose of assessing whether new subject matter is proposed to added, comprise: (a) an abstract that was filed with the complete specification (Reg. 10.2A(a)); (b) a missing part or element of a complete specification that was incorporated into the specification, in accordance with regulation 3.5A or Rule 20.5 or 20.6 of the PCT (Reg. 10.2A(b)); or (c) an amendment that has been made to the complete specification after filing, for the purpose of: (i) correcting a clerical error or obvious mistake; or (ii) complying with paragraph 6(c) of the Act (Reg. 10.2A(c)).

[3] Examiner’s Manual at 5.7.4.2 Allowability of amendments before acceptance.

[4] as discussed in CSIRO v BASF Plant Science GmbH (2020) FCA 328 (CSIRO v BASF).

[5] [2023] APO 36.

[6] subsections 40(2) or (3) of the Act.

[7] CSIRO v BASF at [211]-[215]

[8] [2021] FCA 1457 at [112]