Australia | Post-filing Data And Synergy Claims: Lessons For Patent Drafting

Synergistic combinations occupy a critical space in modern patent law, particularly in the chemical, pharmaceutical, and life sciences industries. While combining known components is common, only those combinations that produce an effect greater than the sum of their parts can rise above a mere admixture and constitute a patentable invention.

Demonstrating and claiming such synergy, however, presents unique challenges: the effect is inherently unpredictable, subject to strict requirements of sufficiency and support, and often scrutinised closely during examination. This article examines how synergistic combinations are treated under Australian patent law and practical strategies for securing robust claims. 

What is a synergistic combination? 

A synergistic combination (also known as synergism) occurs when two or more substances interact so that their combined effect is greater than the sum of their individual effects (often conceptualised as 1 + 1 > 2).

Synergistic effects are commonly observed in the chemical and biochemistry arts, such as in pharmacology, material science, and chemical catalysis. Synergism can occur via many mechanisms, for example combined chemicals may attack a problem using different biological pathways or chemical processes, or where one substance has little to no effect on its own but enhances the efficacy of the primary chemical, or in circumstances where one chemical helps another reach its target site or overcome physical or chemical barriers.

Synergism, however, is inherently unpredictable because it relies on complex, non-linear interactions between the individual components. 

An example of synergism in the agricultural space includes combining certain herbicides or pest repellents which overcome the natural defences of weeds or insects, e.g., pairing natural botanical compounds or chemical surfactants with insecticides, allowing the active chemical to penetrate the insect’s waxy cuticle with greater ease. Another example in the field of oncology relates to certain cancer treatments which can often use synergistic combinations of chemotherapeutic drugs – for example, by hitting multiple independent pathways, oncologists can lower the required dose of each toxic drug while maximizing tumour cell death.

The line between an “admixture” and a “synergistic combination” 

Under s50(1)(b) of the Patents Act, an application or grant may be refused on the ground that the specification claims as an invention:

1. a substance that is capable of being used as food or medicine (whether for human beings or animals and whether for internal or external use) and is a mere mixture of known ingredients; or
2. a process producing such a substance by mere admixture.

An admixture is generally a mere mixture of known ingredients with no cooperation or interaction between the ingredients. In practice, an objection under s50(1)(b) is usually only taken where the invention is a simple recipe.

For the invention to rise above being a mere admixture, there must be a “potential working interrelationship” between the components of the composition, i.e., the result achieved by the combination must be more than might be expected from a mere mixture, such as some synergistic effect or advantage.

Meeting the sufficiency and support thresholds 

Under s40(2)(a) of the Patents Act, a complete specification must “disclose the invention in a manner which is clear enough and complete enough” for the invention to be performed by a skilled addressee (sufficiency).

The test for sufficiency is whether the skilled person can readily perform the invention over the whole scope, as claimed, without needing inventive skill. A reasonable amount of trial and error is permissible, however if the work involved in implementing the invention amounts to an undue burden (such as amounting to a research project) then the sufficiency requirement will not be met. The requirements for sufficiency must be satisfied at the time of filing the complete specification. i.e., an insufficient disclosure cannot be rectified by adding new matter after the filing date of the application.

Section 40(3) requires that the claim/s of a complete specification must be supported by matter disclosed in the specification (support). In addition to needing a basis for each claim in the description, the scope of the claims must not be broader than is justified by the disclosure and the (technical) contribution to the art, i.e., the claims must not encompass embodiments beyond what the specification discloses, and the claimed invention cannot be materially different from the invention disclosed.

Given synergy is not predictable, it naturally follows that a mere assertion in the patent specification of some synergy or similar advantage are unlikely to meet the sufficiency threshold unless the effect has been clearly demonstrated with experimental evidence, or without a credible technical basis of the effect (i.e., a “principle of general application”).

In practice, where patent claims define a synergistic combination, detailed experimental evidence will be required that provides appropriate concentrations or ratios (boundary) of the compounds that will provide the synergistic result, otherwise it would impose an undue burden if the person skilled in the art was required to test all possible combinations to determine those falling within the scope of the claims.

A typical patent claim that defines a synergistic effect between a composition of A and B might read:

“A combination of compounds A and B whereby said combination produces a synergistic effect when used in … [e.g., the treatment of tumours]” 

However, the claim does not necessarily need to explicitly define that a synergistic effect is produced. It is also possible to direct a claim to its use or method.

For completeness, and in relation to inventive step, a synergistic combination typically represents a quintessential “unexpected result” because it directly refutes the presumption that combining known elements will only yield predictable, additive outcomes. However, the ultimate question as to whether a synergistic effect is obvious depends on the facts of the matter and the state of the art.

Admissibility of post-filing data 

Examiners are especially wary of claims to synergistic combinations and, during prosecution, will delve into the experimental data provided in the specification to ensure that the scope of the claims is commensurate with the compositions that show synergism. If there is any question over the veracity of the experimental data demonstrating the synergy, Examiner’s will routinely raise objections under lack of support, sufficiency or inventive step.

One option of addressing these types of issues is relying on post-filing data or supporting evidence. This typically involves the filing of arguments with the additional data or in the form of expert declarations or a declaration from the inventor, to support the submission of additional data. There is no guarantee such data may be accepted by the patent office, and therefore it is preferable to avoid relying on post-filing data as the primary means to overcome such objections raised during prosecution.

In our experience, the Australian Patent Office is routinely dismissing post-filing data and maintaining the objections because the post-filing data was not originally disclosed in the specification at the time of filing. This is a difficult matter, as Applicants are usually in a rush to file patent applications to either secure an early priority date or to “plant their flag” as market leaders. Clients may not always include the most up-to-date data or even the most complete data when filing the complete application.

The Patent Manual of Practice and Procedure (Examiner’s manual) also has limited guidelines concerning the use of post-filing data which leads to inconsistent examination practice and varying degrees of success. 

However, we have found success in relying on post-filing data by referring Examiner’s to the Patent Office decision in BASF Corporation [2019] APO 34 (BASF) as discussed below although consideration of post-filing data has not been judicially considered.

The BASF decision dealing with post-filing data

The leading patent office decision in this regard is BASF, which concerned patent applications defining synergistic mixtures of Bacillus subtilis MBI600 and a second compound selected from fungicidal or insecticidal compounds and plant growth regulators.

During examination, the Examiner was satisfied there would be no undue burden for the skilled person to perform the claimed invention, but objected to the applications for failing to satisfy the sufficiency threshold.

In particular, finding that it was not plausible the invention could be worked across the full scope of the claims on the basis that it was not “plausible” that there were synergies between all of the claimed compounds. BASF sought to address this view by submitting post-filing experimental data which showed that some of the claimed mixtures had indeed shown synergistic activity.

The Commissioner’s Delegate found that while the post-filing experimental data demonstrated that some of the compounds do indeed have synergy, that data was not present in the specification as filed (at [68]). BASF submitted that the post-filing evidence supplemented the evidence contained in the specifications and showed (based on the underlying mechanism disclosed) that it would be expected for the combinations to show synergy.

The Delegate accepted the evidence and found that the post-filing data confirmed the expectation of the skilled person having regard to the specification as filed and the common general knowledge as at the filing date.

In summary, the decision in BASF confirms that post-filing experimental data can be used to address sufficiency and support provided the data merely confirms the information disclosed in the specification as understood by a skilled person in the art rather than “patching up” deficiencies in the specification.

Tips for patent drafting

• Look for synergy in the experimental data, i.e., more than additive effects, and include enough detail of the experimental design and levels of underlying variation to provide convincing evidence to the skilled person that the deviation between observed and predicted responses provides the synergistic outcome. For example, it would be advisable and strongly recommended to look for different concentrations at the ratio/s that provides synergy in order to define the boundary of the claimed invention, and the deviation from that ratio where the synergistic effect remains in effect.
• The synergistic effect cannot be an afterthought and must be plausible from the application as originally filed. Accordingly, it is beneficial to call out the synergy, and to direct claims commensurate in scope with the unexpected synergistic results provided in the specification.
• Where the experimental data does not quite expand to the full extent of the expected range of synergistic combinations, it may be possible to identify a plausible / credible technical principal of general application which underpins the demonstrated synergy, thereby justifying broader claim scope.

Synergistic drug combinations are a cornerstone of the modern pharmaceutical industry.

By administering agents where the combined effect is greater than the sum of their independent effects, the pharmaceutical can significantly reduce toxicity, delay or overcome drug resistance, and expand the lifespan of existing therapeutics.

However, it is important to ensure the patent application focuses on the synergism at the time of filing and to provide sufficient experimental data which provides a credible and plausible disclosure. This can avoid the need for post-filing data although this may not be realistic in all cases. 

How we can help

Protecting synergistic inventions requires careful consideration from the outset. Our specialist attorney and legal teams in Australia work with clients across the chemical, pharmaceutical and life sciences sectors to identify, document and claim synergistic effects in a manner that supports robust and commercially valuable patent protection.