Omission of best method
disclosure can be rectified in a
divisional application
Inspire September 2018
The Patent Office
decision in Merial v
Bayer 1 earlier this
year highlighted the
grave risks of failing
to disclose the ‘best
method known to the
applicant of performing
the invention’ as
required by section
40 of the Australian
Patents Act.

11 Omission of a best method
disclosure can have catastrophic
consequences for patent applicants
in Australia, regardless of any wilful
intent to conceal key aspects of
the invention. Applicants are thus
advised to proactively address best
method issues, in collaboration with
their Australian patent attorneys,
prior to filing their application.

However, a question that was
left open from this decision
was whether such a failure
might be remedied by filing a
divisional application with the
necessary disclosure added to
the specification. A much more
recent acceptance of a divisional
application indicates that – in the
view of the patent office at least –
the answer to this question is yes.

Applicants should therefore
note the possibility of side-
stepping a patent validity issue
by filing a divisional application
which includes an adequate
disclosure of best method. It
remains to be seen, however,
whether the courts will find that
section 40 imposes an onerous
obligation to disclose the current
understanding of best method
when filing divisional applications.

The latest case
In Kineta, Inc 2 , the patent office
refused AU2012315953 on the
basis that the specification taught
no method (and thus omitted the
best method) of obtaining the
therapeutic compounds claimed
in the application. Since the
application was subject to the
post-Raising the Bar provisions of
the Patents Act, the specification
could not be amended to add the
necessary best method disclosure.

Kineta then filed divisional
application AU2017254812,
which disclosed that the
compounds had been sourced
from a contract manufacturer
(known to Kineta when filing the
parent) and also described the
synthetic methodology (which
Kineta did not know at the parent
filing date). The application has
recently been accepted without
objection from the Examiner.

Date when best method
must be disclosed?
Although case law is inconclusive
on the point, it is generally accepted
that the best method disclosure
obligation must be fulfilled at the
filing date of an application. For
a divisional application, however,
the further question is whether
the relevant filing date is that of
the divisional application itself or
of the original parent application.

Given the acceptance of
AU2017254812 after the refusal
of its parent, the patent office
has apparently concluded that
the relevant date is the divisional
Dr Matthew Overett, Associate
BSc (Hons), PhD Chem, MIP
matthew.overett@pof.com.au Merial, Inc. v Bayer New Zealand
Limited [2018] APO 14
2 Kineta,Inc. [2017] APO 45 (Kineta Inc)
1
info@pof.com.au filing date. This contrasts with
the requirement that an enabling
disclosure of the invention must be
found in the parent specification if
divisional status is to be claimed.

Unintended consequences?
While providing a happy outcome
for the applicant in this case, the
patent office’s interpretation raises
a troubling question: does the
applicant have a duty to disclose
their current understanding of
best method in the divisional
specification, or is it sufficient to
rectify – at the divisional filing date
– the omission of the best method
known when filing the parent?
Divisional applications are
typically filed many years after
the priority date of the original
parent application, by which time
the underlying technology may
have been further advanced or
commercialised. In practice, the
divisional specification is seldom
updated to reflect post-filing
developments of the invention.

Indeed, such a requirement
would be unacceptable to many
applicants, given the practical
burden of ascertaining current
“best method” and the implication
that confidential technical
or commercial information
may need to be divulged.

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