Assessing sufficiency: a temporal problem
The Patents Act 1990 (Cth) requires that a specification fully describe the invention, including the best method known to the applicant for performing the invention. However, the Act is silent on the actual date at which the specification is to be considered for compliance with these requirements. In the recent case of Pfizer Overseas Pharmaceuticals v Eli Lilly and Company, the Full Federal Court turned its attention to this issue and reached a conclusion contrary to the practice of other jurisdictions. This note briefly reviews some of the earlier Australian case law considered by the Court in reaching its conclusion and considers the potential consequences of that conclusion.
The requirement of sufficiency
In return for the monopoly granted by a patent, a patentee is required to “make the nature of his invention, and how to perform it, clear and intelligible to persons having a reasonably competent knowledge of what was known before to which his patent relates and having reasonably competent skill in the practical mode of doing what was then known”.1 Historically, this requirement is known as “sufficiency” and is codified in the Australian Patents Act 1990 (Cth) (“the Act”) by s 40(2)(a), which provides:
“A complete specification must:
(a) describe the invention fully, including the best method known to the applicant of performing the invention;…”.
Thus, a specification must provide a full description of the invention that makes the nature of it plain to the person skilled in the art. Furthermore, this requirement cannot be satisfied unless the best method of performing the invention known to the applicant is also disclosed. The rationale behind this is to prevent a person securing the “benefit of monopoly without giving to the public the corresponding consideration of the knowledge of the best method of performing the invention”.2
Assessing whether a complete specification satisfies the requirements of sufficiency involves a two-part consideration: (a) the adequacy of the disclosure; and (b) the date(s) at which this is to be assessed.
(a) Adequacy of Disclosure
The question of sufficiency is one of fact as determined by evidence from a person skilled in the art (who may in reality be more than one person). It is well settled that in determining whether a complete specification satisfies s 40(2)(a), regard must be had to the whole document; both the body (description) and the claims, as well as any accompanying illustrations. The specification need not describe the manner in which the invention is to be performed with the level of detail that might be found in, for example, an instruction manual or manufacturing specifications. Nor is it necessary that the addressee should be able to perform the invention without any (routine and non-inventive) trial or experimentation. Thus a specification is sufficient if it will enable the skilled person to produce something within each claim without resort to further inventive input or prolonged study. It follows then that a description of only one embodiment can fulfil the requirement of sufficiency. Furthermore, the best method of performance need not include an actual working example; it may be described in general terms, or may even be a claim. Notably, where a specification does contain more than one descriptive method, embodiment or working example, it is not necessary to explicitly identify which of these is the best method.
(b) When is sufficiency assessed?
With the exception of micro-organism-related inventions3, the Act does not contain any express provisions stipulating the time at which a specification must comply with the requirements of full description, including best method, i.e. whether at filing, publication, grant or some other time.
In Rescare Ltd v Anaesthetic Supplies Pty Ltd4 (Rescare), one of the first cases where this issue was considered by the Australian Courts, the question before Gummow J was whether the specification included the best method known to the applicant in accordance with the corresponding s 40(1)(a) of the 1952 Act. His Honour was able to reach a conclusion on the basis of factual evidence rather than on a point of law. However, as an aside, but without providing any further reasoning, His Honour also made the obiter comment that the “adequacy of disclosure should be judged by reference to the time from which dated the monopoly granted the applicant in exchange for the disclosure”. It is clear that His Honour was referring to the filing date, being “the date from which the term of the patent runs.”
In the subsequent case of Kimberly-Clark Australia Pty Ltd v Arico Trading International Pty Ltd,5 (Kimberly-Clark) the High Court took a different view. The Court was asked to consider a specification that had been amended during examination. The Court considered that in the revocation action at hand, the issues, including inadequate disclosure, were to be determined by reference to the terms of the Patent as granted. Thus, it is clear that a specification to be assessed for compliance with the full description requirement may be different from that which was filed.
In the recent Pfizer v Eli Lilly judgements of the Federal6 and Full Federal Courts7, the invention at issue related to a method of orally treating man to cure or prevent erectile dysfunction. The best method for performing the invention, sildenafil citrate (Viagra), was introduced into the specification by way of amendment (in the form of a claim) nearly three years after filing the application. At first instance, Heerey J asked the questions “What is the date for determining sufficiency?” and “What is the relevant date for determining whether the best method has been disclosed?”. By examining the Dictionary meaning attributed to “complete specification” in the Act, which included a specification as amended, and noting the expression of present tense in the relevant revocation provision s138(3)(f): that the specification does not comply with s 40(2) or (3), His Honour concluded that the answer to both questions was, at the earliest, the date of grant. It was further noted that the date of commencement of proceedings also had logical basis. Thus, although the relevant method was only introduced into the specification some three years after filing, the requirement of disclosing the best method known to the applicant was held to be satisfied.
On appeal, the Full Federal Court contemplated the Dictionary definition of a “complete specification” together with the allowable amendments under the Act. It concluded that it is the specification as amended that must be construed in order to determine compliance with s 40(2)(a). In doing so, it considered the operative limitations on the power of amendment8, noting that: “If a proposed amended disclosure of a best method somehow caused the specification to claim matter not in substance disclosed in the specification as filed, the proposed amendment would not be allowable”9. Their Honours therefore agreed with the trial judge that the date for assessing the disclosure of full description, including best method of performance, is not earlier than the date of grant and could be as late as the date of commencement of the proceeding.
In view of these decisions, it is clear that an applicant could file an application lacking a full description of the invention, and add this at a later time provided that this did not result in the claiming of new matter. In isolation, this may have a logical basis in the language of the Act and is consistent with a public interest policy whereby the quid pro quo for the grant of a patent, i.e. full public disclosure of the invention and instruction how to perform it, does not need to be given until the patent is actually granted. This approach may be sufficient if only the interests of the patentee and general public are of concern. However, as outlined below, it could disadvantage contemporaneous inventors who “may have greater knowledge at that time but were beaten to the post while they were waiting to be in a position to file a sufficient application.”10
The Common General Knowledge
It is trite law that a complete specification is to be construed in the light of the common general knowledge, in the position of a person acquainted with the surrounding circumstances as to the state of the art at the time, i.e. the skilled addressee. However, if the specification to be construed is that at grant, this raises the question of whether advancements in the art, subsequent to filing, can be used to satisfy s 40(2)(a).
Take, by way of example, the following scenario. Two inventors simultaneously and independently conceive the same new inventive concept but neither is able yet to envisage a means of performing the invention. Nevertheless, one inventor files a patent application in the hope or expectation that a means for performing the invention will be identified before his patent is granted. The second inventor does not file an application but investigates means for performing the invention. Subsequent to the filing of the first patent application, the second inventor identifies a means for performing the invention and files his own patent application, which includes the best method of performance as part of the full description, and publishes his method. The method subsequently becomes common general knowledge in the art of the invention. If, for the purpose of full description, the state of the common general knowledge is taken to be that on which the specification is to be construed, i.e. at grant, the first inventor may then be in a position to rely on what is now common general knowledge to allow a full description disclosure to be construed from the specification whilst enjoying priority rights.
To overcome such a situation, well-established principles, followed by the High Court in Kimberly-Clark, and cited approvingly by the Full Federal Court in Pfizer Overseas Pharmaceuticals v Eli Lilly and Company7 (Pfizer), stipulate that the state of the common general knowledge used to construe a specification is that as it stands before the priority date. Therefore, although the form of specification to be construed is that at grant, the state of the common general knowledge used to construe it is that immediately before the priority date. Subsequent advancements in the common general knowledge cannot be used to construe the specification in order to ameliorate full description deficiencies.
The applicant's knowledge of the best method
Of course, full description compliance under s 40(2)(a) necessarily requires an identification of the best method known to the applicant. The question then also arises as to the appropriate date for identifying the applicant’s knowledge of the best method. The Full Federal Court in Pfizer considered this point and noted the date at which the best method known to the applicant is to be identified is conceptually distinct from the date by which the specification’s full description of the invention must include a disclosure of it. In stating that it is the best method known to the applicant as at the filing date that must be disclosed, it cited with approval the obiter dictum of Gummow J in Rescare. At the time of those proceedings, the patentee was using a “one tube” apparatus acknowledged to provide advantages over the “two tube” form described in the specification and his Honour was asked to consider whether the specification was deficient for not describing the improved apparatus. As noted above, His Honour could decide the issue on factual evidence alone but expressed acceptance of the submission that the relevant date for identifying the applicant’s knowledge of the best method was the filing date.
The Courts have therefore set out a number of considerations for determining whether or not a complete specification satisfies the sufficiency requirement:
- the date at which the specification is construed – at least that of grant;
- the state of the common general knowledge – that immediately before the priority date; and
- the date of the applicant’s/patentee’s knowledge as to best method – that at the filing date.
The findings of the Courts with respect to (ii) and (iii) at least would appear to have logical basis in policy. An applicant should not be permitted to take advantage of subsequent advancements in the art to ameliorate an otherwise deficient specification and thus public policy would dictate that the common general knowledge with which the specification is construed is that as it was immediately before the priority date. Similarly, it is logical to adopt the date of filing the specification as the date at which the applicant’s knowledge of best method is assessed. Since the obligation for disclosure only arises at filing, it makes no sense to impose an earlier date than this. Adoption of a later date would place an undue burden on the applicant to amend the specification as new developments arise (assuming such amendments would be allowable).
However, a full description of the invention, including the best method known to the applicant for performing the invention, may nevertheless potentially be kept secret from the public until at least the date of grant. This potentially allows the applicant to withhold until grant not only a means for performing the invention but perhaps even the full nature of the invention provided that subsequent amendments to correct this are allowable. This may pose no issue for those who believe that the consideration for the grant of a patent does not need to be given until the government fulfils its side of the bargain, i.e. the actual grant of a patent. However, for those who consider that the quid pro quo on the inventor’s part must be satisfied at an earlier point, before the patent is granted, this is clearly unsatisfactory. There is an argument that a more logical time for complying with s 40(2)(a) is the date of publication (18 months from the earliest priority date), being the date when the public is informed of the invention and potentially that from which a patentee may seek infringement redress. However, even this date does not ameliorate a situation whereby an applicant is unable to provide a full description of the invention at filing, yet still benefits from the advantages of the priority date. Such a scenario can only be overcome by setting the date for compliance with s 40(2)(a) as the date of filing.
As the law currently stands, it would appear that a filed specification can be subsequently amended, within the provisions for allowable amendments, to ameliorate full description deficiencies. Amendment can take place at least up until grant or even up until the revocation proceedings commence. Taking into consideration the position at three different dates when assessing sufficiency somewhat incongruously allows a valid application to be filed and a valid priority date to be obtained with a specification which is lacking a full description, provided that this is present before grant or revocation proceedings.
That said, applicants who choose to proceed with filing a deficient Australian specification, intended to form the basis for foreign applications, and with the intention of amending to include the full description at a later stage, do so at their own peril. Other major jurisdictions have no such temporal anomalies regarding their sufficiency requirements or indeed allow post-filing amendments which incorporate new matter. Reliance on the current view of the Australian Courts to subsequently ameliorate any full description deficiencies in an Australian originating application may prove fatal for corresponding applications in other jurisdictions.
- Edison lamp & Swan United Electric Light Co v Holland (1889) RPC 243 at 279
- American Cyanamid Company v Ethicon Limited (1979) RPC 215 at 269
- Section 6 sets out the dates by which the microorganism description requirements are taken to be satisfied.
- Rescare Ltd v Anaesthetic Supplies Pty Ltd (1992) 111 ALR 205
- Kimberly-Clark Australia Pty Ltd v Arico Trading International Pty Ltd (2001) 207 CLR 1
- Eli Lilly and Company v Pfizer Overseas Pharmaceuticals  FCA 67
- Pfizer Overseas Pharmaceuticals v Eli Lilly and Company  FCAFC 224.
- Allowable amendments are governed by s 102 which provides: (1) An amendment of a complete specification is not allowable if, as a result of the amendment, the specification would claim matter not in substance disclosed in the specification as filed.
- Although a recent decision of the Federal Court (Pfizer Inc v Commissioner of Patents  FCA 137) has suggested that the meaning of “in substance disclosed” could have broader operations than previously considered.
- Monotti, A., “Sufficiency of Description: At what time is adequacy to be considered?” (2005) 16 AIPJ, 152-164