Claim disclaimers
in Australian
patent practice
Inspire March 2022
Patent applicants and patentees may amend the claims of their patent
specification to distinguish the invention from relevant prior art. The use
of a disclaimer – if permissible under s 102 of the Patents Act – can be an
effective strategy to limit the claim scope to the minimum extent necessary.

4 In deciding the substantive
The decision
opposition by Merial, Boehringer
The relevant version of s 102,
Ingelheim’s predecessor, the
predating the Raising the Bar Act,
Patent Office found that claim 1
stipulates that “an amendment
lacked novelty over prior art which
… is
not allowable
if, as a result of
disclosed an anti-mastitis formulation
the amendment,
the specification
containing acriflavine, an acridine
would claim
matter not
in substance
compound. 2 While acriflavine was not
disclosed in
the specification
as explicitly taught to be present as an
filed”. Similarly,
s 102
prohibits antiseptic, and had other known uses,
amendments after acceptance of
the evidence established that the
an application if the resultant claims
skilled person understood acriflavine
would not be fairly based on matter
to have antiseptic properties and
described in the specification.

that acriflavine would inherently have
Boehringer Ingelheim argued
an antiseptic action in the disclosed
that Elanco’s amendment was
amount present in the prior art
impermissible under this framework,
formulation. In response, Elanco
The background
because the specification did not
amended claim 1 with the following
Elanco’s accepted patent application
sufficiently disclose an invention
novelty-restoring disclaimer:
related to the use of teat seal
where acridines are specifically
“wherein the antiseptic is not an
formulations to prevent mastitis in
excluded from use as the antiseptic
acridine”. Boehringer Ingelheim then
animals. The claimed formulations
compound. Indeed, the specification
appealed the Patent Office decision
contain an oil-based barrier material
did not mention acridines at all, either
allowing the amendment to the
mixed with an “antiseptic compound
as antiseptic compounds to be used
Federal Court.

… in sufficient quantity to act
or avoided. Instead, the specification
effectively as an antiseptic”.

identified a small number of
preferred, non-acridine antiseptic
compounds, and a list of preferred
1 Boehringer Ingelheim Animal Health USA Inc v Elanco New Zealand [2021] FCA 1457
properties of suitable antiseptics.

2 Merial, Inc v Bayer New Zealand Limited [2017] APO 27.

For example, if a claim relating
to ‘a vehicle’ is anticipated by prior
art which discloses a ‘bicycle’, an
amendment restricting the claims to
‘a vehicle which is not a bicycle’ will
restore novelty at the least cost to
the claim scope.

A recent Federal Court decision
in Boehringer Ingelheim v Elanco 1
confirms the generous dispensation
for the allowability of such
amendments under Australian patent
law, at least for patents to which the
Raising the Bar amendments to the
Patents Act do not apply.