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A bar to re-examination

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  • Mar 10, 2021
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In Australia, there are different options to challenge the validity of a patent application or granted patent.  This can be of significant interest from a freedom to operate perspective when a business is planning to launch or commercialise a product or process, regardless of whether the product or process is covered by its own intellectual property.

Challenging a patent application or patent

(i)           Third party submissions

A patent application can be challenged pre-acceptance (prior to being allowed by the examiner during prosecution) by filing third party submissions.  Any party may file third party submissions up to three months following the date of advertised acceptance of a patent application in Australia.  The Notice is filed with any documents relevant to the assertion that the invention claimed is not novel and/or does not involve an inventive step. 

(ii)          Re-examination

It is also possible to request re-examination between acceptance and grant which is at the Commissioner’s discretion. 

On the other hand, if a third party requests re-examination following grant, re-examination must be conducted and either an adverse or non-adverse report must be issued.

During re-examination, an examination report will issue which outlines the examiner’s findings.  In the case of an adverse report, the patentee will be given the opportunity to respond with its own written submissions and/or amendments.  If the patentee cannot resolve outstanding issues encountered during re-examination, the Commissioner will typically set the matter for a hearing prior to revoking the patent either wholly or in so far as it relates to a particular claim if the patentee is unsuccessful.  

Hearings are typically rare during re-examination as most outstanding issues can be resolved by a patentee by filing written submissions or amendments in reply to a re-examination report.  The most common grounds which are difficult to resolve as they are subjective are issues relating to inventive step (obviousness) and patentable subject matter (such as manner of manufacture for software patents).

(iii)         Opposition proceedings

The validity of a patent application can also be challenged by commencing (pre-grant) opposition proceedings.  This involves filing a notice of opposition, which must be filed within three months of the date on which acceptance of the (opposed) application is advertised.

Opposition proceedings typically involve the preparation of expert evidence.

(iv)         Revocation

If a patent application proceeds to grant, a third party has the option of challenging the validity of the patent claims by commencing revocation proceedings before an Australian court or, alternatively, seeking revocation of the claims during infringement proceedings commenced by the patentee. 

Ex-parte

Under Australian practice, third party submissions and re-examination requests are ex-parte.  That is the requestor is not a party to the process and there is no opportunity for further iterations of evidence.

Re-examination considerations and advantages

In this article, we will focus on the advantages of filing a request for re-examination as a cheaper and more time efficient route to challenge validity of patent claims. 

Compared to opposition and revocation proceedings, re-examination can be orders of magnitude cheaper and generally issues can be resolved in a matter of months rather than years.  This can provide more clarity for a party’s commercial objectives in a shorter time frame which would otherwise delay product launches and commercial activities.

Traditionally, re-examination was a less popular route because prior to the commencement of the new Patents Act (Raising the Bar) which came into effect on April 2013, re-examination was limited only to the grounds of novelty and inventive step.  Unless a party had “knock-out” prior art for novelty purposes, challenging inventive step was notoriously difficult as assessing inventive step in Australia requires expert evidence from expert witnesses as discussed above and is highly subjective. 

Accordingly, most Australian attorneys would not recommend re-examination if the main ground of challenge was inventive step.  This is highlighted by the Merck & Cie decision below.

However, as a result of the changes to our law, the grounds which could be considered during re-examination were expanded to include full description (including best method of performance), clarity and succinctness, patentable subject matter and fair basis/support.  Usefulness is also considered, but in context of whether the claimed invention achieves the promised benefit. 

Difficulty with inventive step – Merck & Cie [2020] APO 45

A recent Patent Office decision (Merck & Cie) highlights the high bar demanded of third parties to invalidate a granted patent when requesting re-examination in relation to the ground of inventive step.  The Delegate dismissed the ground of inventive step after oral hearing proceedings on the basis that the Delegate could not be practically certain that the granted patent was invalid in view of the evidence provided despite issuance of three re-examination reports maintaining lack of inventive step during re-examination proceedings.

This decision reinforces the already accepted notion of the difficulty third parties face when relying on re-examination at the Patent Office to invalidate a granted patent in respect of inventive step.

The claims of the Australian Patent 2012200512 filed in the name of Merck & Cie (the Patentee) are directed to formulations of a specific polymorph of the compound (6R)-L-erythro-tetrahydrobiopterin dihydro-chloride (referred to as Form B).  The formulations comprise one, or both, of the pharmaceutical excipients polyvinylpyrrolidone (PVP) and/or dicalcium phosphate (DCP).

On 23 October 2017, a third party (the Requestor) filed a request for re-examination.  Objections were raised by the Examiner under the ground of inventive step.  Three rounds of submissions were filed by the Patentee to address the lack of inventive step objection, however, the submissions were not considered to be persuasive.  

As a result, the Examiner assigned the matter to a hearings officer to consider revocation and that the Patentee could request a hearing to contest the decision.  A hearing was requested by the Patentee.

(i)           The Arguments

The Requestor raised the following grounds for re-examination:

a)            the claimed invention lacked novelty;

b)            the claimed invention lacked an inventive step; and

c)            the claims are not fairly based on the disclosure of the specification.

Nine prior art documents were filed with the request including expert evidence in the form of declarations by three expert witnesses. 

The only ground raised in the re-examination reports by the Examiner was inventive step and was the primary ground during hearing.  Additional documents had been cited by the Examiner to support lack of inventive step.

The Examiner asserted that the claims lacked an inventive step because the polymorph Form B was known from the cited documents, and that its outstanding properties make it “especially feasible” for pharmaceutical application. 

Similarly, the Examiner considered that the use of active pharmaceutical ingredients in combination with excipients PVP and DCP (either alone or in combination) was routine based on the teachings of the cited art.  Accordingly, a person of ordinary skill would be expected to simply substitute the active pharmaceutical ingredients described in the cited art with the improved polymorphic Form B in combination with the excipients disclosed.

The major issue in determining whether the claimed invention had an inventive step was that the Examiner asserted that the specification did not describe a problem to be solved (namely stability).  The Examiner noted that the “specification does not appear to suggest any particular problem when formulating compositions of the polymorphic Form B, nor does it indicate that there is any particular difficulty in formulating Form B” and that as a consequence “there are no proposed solutions which have a need for invention when preparing a pharmaceutical composition” and therefore the claimed invention is obvious.

Similar issues had been raised during prosecution that the selection of polymorph Form B in combination with excipients PVP and DCP were routine.  However, the Patentee had drawn analogies to the circumstances of Bristol Myers Squibb v Apotex and argued that these excipients (either alone or in combination) provided improved hygroscopicity (absorption of moisture from surrounding atmosphere) that could not have been predicted.  The application was accepted in view of this argument.  However, the Examiner considered that the supplementary material provided by the Requestor established that the use of these ingredients was obvious. 

(ii)          The Decision

Despite the arguments raised by the Requestor and the Examiner that a specific problem was not identified by the specification and particularly not by any reformulation development around Form B with any advantageous excipients, the Delegate was satisfied that the problem to be solved, as provided by the Patentee, is the provision of a formulation of (6R)-L-erythro-tetrahydrobiopterin dihydrochloride that has high storage stability.

The evidence before the Delegate indicated that while (6R)-L-erythro-tetrahydrobiopterin dihydrochloride was known to exist as a white crystalline solid, this was the only crystal form described in the prior art.  The Delegate found that polymorphism requires at least two different crystal forms and it was only once the Patentee discovered different crystal forms that the white crystal of the prior art could be considered a polymorph (form B).  Polymorph forms was therefore not common general knowledge. 

No evidence was provided regarding the storage stability of (6R)-L-erythro-tetrahydrobiopterin dihydrochloride and that tablets comprising (6R)-L-erythro-tetrahydrobiopterin dihydrochloride together with PVP and/or DCP were known or even common general knowledge.

The Delegate found that the problem in the present case is the provision of a formulation of (6R)-L-erythro-tetrahydrobiopterin dihydrochloride that has high storage stability.  The Delegate noted that the claimed combination as a whole must be considered when considering inventiveness and not the individual features.

The evidence from the experts indicated that there were a number of alternative strategies that could be employed to formulate the active ingredient, and even if seeking an excipient to improve the stability of the formulation, there were a number of alternatives that could be employed. 

As a result, the Delegate found that on balance there was insufficient evidence to determine that the claims are invalid on the ground of lack of inventive step in view the cited art and the common general knowledge. 

Implications

This decision reinforces the understanding by practitioners that re-examination should be relied on as an alternative to opposition and revocation proceedings when the matters to be considered are relatively straightforward.  That is, the substantive grounds relied upon by a third party is inter alia novelty and support.

Reliance of re-examination proceedings are typically difficult when attempting to invalidate a patent based on the ground of inventive step. 

This difficulty was also noted by the Delegate which stated that “[t]he present determination has also not been helped by the evidentiary constraints of re-examination where the requestor is not a party to the process and there is no opportunity for further iterations of evidence or, in the case of post-grant court proceedings, cross examination to further explore the issues in contention”.[1] 

For matters relating to the ground of inventive step, it is recommended that invalidity be established by opposition proceedings (pre-grant) or revocation in Court (post-grant) proceedings as these are inter partes proceedings such that a third party can have the opportunity to heard in full.

Alternative grounds

Despite the high bar encountered during re-examination in the context of inventive step, re-examination can still be a useful and cost-effective tool when relying on the alternative expanded grounds as discussed above.

This was highlighted in an earlier Patent Office decision of Huping Hu (2014) APO 17.  Unusually in this case, the Commissioner exercised their discretion in requesting re-examination after grant compared to a request filed by a third party.  During re-examination, the Commissioner raised additional grounds relating to utility, patentable subject matter (lack of manner of manufacture) and full description.

In this decision, the Delegate found that the patent lacked utility, patentable subject matter and the specification did not fully describe the invention.

The Delegate revoked the patent as the Delegate considered that the deficiencies could not be addressed by amendment.

Recommendation

As a result of the expanded grounds, re-examination can be a useful tool to challenge validity.  If a potentially infringing commercial product relies only on a specific embodiment such as using specific chemical compositions, re-examination can be used to potentially force a patentee to amend the claims which may exclude a potential commercial product by relying on the grounds of support and disclosure for example.

For instance, if a patent application or patent has unduly broad claims potentially covering the embodiment but is arguably not supported or enabled by the description and examples (often observed in the Chemical and Life Sciences space), raising the ground of support can potentially force the patentee to amend claims by narrowing which are no longer covered by the scope of the amended claims and avoid potential infringement.

Since more grounds are now available under the post-Raising the Bar Act, the prospects for successfully challenging validity through re-examination have improved but the thresholds remain high and patentees are given ample opportunity to save their claims through amendment.  This can make a potential infringer’s position better from a freedom to operate perspective but worse from a revocation perspective.

If you are interested in requesting re-examination of a patent or would like further information, please contact one of our expert attorneys.


[1] Merck & Cie [2020] APO 45, [98].

Authored by David Hvasanov, PhD and Charles Tansey, PhD