Syngenta Participations AG v Monsanto Corporation

Case •

[2006] APO 16

•

21 April 2006

ABSTRACTS OF DECISIONS

DECISION OF A DELEGATE OF THE COMMISSIONER OF PATENTS

Application  :          No. 723452 in the name of Syngenta Participations AG

Title:          Synergistic Herbicidal Compositions of Metolachlor

Action:          Opposition under Section 59 by Monsanto Corporation, and Objection to the request for leave to serve further evidence by Monsanto Corporation.

Decision:          Issued 21 April 2006.

Abstract

The invention relates to the herbicidal use of a combination of the S-enantiomer of the well known herbicide metolachlor with certain co-herbicides.  The herbicides are applied either as a single composition, or in a method comprising separate treatment with S-metolachlor and the co-herbicide.

Leave was granted to serve further evidence since a prima facie view of the further evidence indicated that it was likely to be important in the opposition proceeding given the nature of the issues addressed by the proposed evidence.

The opponent has not adequately established that the claims lack novelty, inventive step, and fair basis, and consequently the opposition fails on these grounds.

As the opposition has been unsuccessful, costs are awarded against Monsanto.

PATENTS ACT 1990

DECISION OF A DELEGATE OF THE COMMISSIONER OF PATENTS

Re:Patent Application No.  723452 by Syngenta Participations AG, Opposition under Section 59 by Monsanto Corporation, and Objection to the request for leave to serve further evidence by Monsanto Corporation.

BACKGROUND

  1. Patent application number 98218/98 was filed on 24 December 1998 by Novartis AG, which subsequently changed its name to Syngenta Participations AG (“Syngenta”).  The application is a divisional of 52763/96 (697026) which claims a priority date of 12 April 1995 from Swiss Patent Application 1072/95.  The parent application was advertised accepted on 24 September 1998.  A notice of opposition to the grant of 697026 was filed on 22 December 1998, and the parent application was subsequently withdrawn on 29 June 2000. 

  2. The divisional application was examined by the Commissioner and advertised as accepted under the serial number 723452 on 24 August 2000.  Monsanto Company (“Monsanto”) filed a notice of opposition on 22 November 2000.  A statement of grounds and particulars was served on 21 February 2001. Service of evidence in support was completed on 9 November 2001, service of evidence in answer was completed on 9 October 2003, and service of evidence in reply was completed on 11 June 2004.  Monsanto opposed the grant of the patent on the grounds of novelty, inventive step, manner of manufacture and section 40 deficiencies.

  3. Requests to amend the specification were filed on 21 March 2002 and 21 May 2003.  Allowance of the amendments was advertised on 28 November 2002 and 11 November 2004 respectively. 

  4. On 13 September 2005, Syngenta applied to serve further evidence.   Monsanto objected to this further evidence on 27 September 2005, and the matter was set for hearing together with the section 59 matter.  Syngenta filed additional further evidence on 28 September 2005.  Evidence in response to the further evidence was filed by Monsanto on 15 November 2005.

  5. The oppositions were heard in Canberra on 29th and 30th of September 2005.  Syngenta was represented by Mr Christian Dimitriadis of counsel, assisted by Dr John McCann and Mr Paul Power, Patent Attorneys of Spruson & Ferguson.  Drs Klaus Hohenberger and Marco Quadranti of Syngenta Participations AG were also in attendance.  Monsanto was represented by Mr Bruce Caine of counsel and Dr Bruce Wellington, Patent Attorney of E. F. Wellington & Co.

    The evidence

  6. Evidence in support consisted of statutory declarations by:

    • Christopher Preston, employed by Department of Applied and Molecular Ecology, Waite Campus, The University of Adelaide, South Australia, dated 1 November 2001 and comprising Exhibits CP-1 to CP-7 (hereinafter Preston #1).
    • Ronald Joseph Brinker, employed by Monsanto Company, St Louis, Missouri, USA, dated 14 August 2001 and comprising Exhibits RJB-1 to RJB-7 (hereinafter Brinker #1).
    • Bruce Stephen Wellington, dated 14 May 2001 and comprising Exhibits BSW-1 to BSW-55.
    • Bruce Stephen Wellington, dated 2 August 2001 and comprising Exhibits BSW-56 and BSW-57.

  7. Evidence in answer consisted of statutory declarations by:

    • Marian T. Flattery, employed by Syngenta Participations AG, Basel, Switzerland, dated 27 May 2002 and comprising declarations I to VI that had previously been filed in the United States Patent and Trademark office (four by Manfred Hudetz and two by Willy T. Ruegg).
    • Willy T. Ruegg, employed by Syngenta Participations AG, Basel, Switzerland, dated 6 May 2003.
    • John Cameron, employed by Independent Consultants Australia Network Pty. Ltd., Hornsby, NSW, dated 9 September 2003 and comprising Exhibits JC-1 to JC-5 (hereinafter Cameron #1). 
    • John Cameron, dated 8 October 2003 (hereinafter Cameron #2). 

  8. Evidence in reply consisted of statutory declarations by:

    • Ronald Joseph Brinker, dated 3 June 2004 and comprising Exhibits RJB-8 and RJB-9 (hereinafter Brinker #2).
    • Christopher Preston, dated 7 June 2004 and comprising Exhibits CP-8 to CP-12 (hereinafter Preston #2).

  9. Further Evidence consisted of statutory declarations by:

    • John Cameron, dated 6 September 2005 and comprising Exhibit JC-6 (hereinafter Cameron #3).
    • Paul Anthony Power, dated 28 September 2005 and comprising Exhibits PAP-1 to PAP-4.
    • Marco Quadranti, employed by Syngenta Participations AG, Basel, Switzerland, dated 28 September 2005 and comprising Exhibit MQ-1.

  10. Evidence in Response consisted of a statutory declaration by Ronald Joseph Brinker, dated 8 November 2005, and comprising Exhibits RJB-10 to RJB-13 (hereinafter Brinker #3).

    The application for leave to serve further evidence.

  11. In their request of 13 September 2005, Syngenta sought to file further evidence in the form of a statutory declaration (Cameron #3) on the basis that:

    “(t)he declaration addresses issues which were raised in the evidence in reply and which we believe were not previously raised.  This may be in part due to amendment of the claims after the evidence in support was completed.”

  12. Following hearing, and in order to expedite matters, Syngenta provided a schedule identifying aspects of the evidence that they wished to rely upon.  In summary, Syngenta sought to rely upon: paragraphs 1to 17, 20 to 22, 51 to 54, 59 to 62 and 64 of Cameron #3; the Quadranti declaration in its entirety; and Power paragraphs 1, 2 and 7, and Exhibits PAP-1 and PAP-4.  Parties agreed at hearing that two European Patent Office decisions (PAP-2 and PAP-3) did not need to be served in evidence, but could be relied upon in the usual manner.  Syngenta elected not to rely upon paragraphs 18, 19, 23 to 50, 55 to 58 and 63, instead relying on Mr Cameron’s previous declarations.

  13. Before granting leave to serve further evidence, the Commissioner must be reasonably satisfied that the serving of further evidence is appropriate in all the circumstances.  In Emory University v Biochem Pharma Inc. [1999] APO 50, the delegate in exercising his discretion was guided by the decisions of Burchett J in Ferocem Pty Limited v Commissioner of Patents (1994) 38 IPR 243, and A Goninan & Co Ltd v Commissioner of Patents (1997) 38 IPR 213 on the operation of regulation 5.10(5) in relation to extensions of time. Whilst these decisions deal with extensions of time for filing evidence, the general principles flowing from them are equally applicable to the filing of further evidence. These principles include that:

    • The power is discretionary: Regulation 5.10 confers a broad discretion, which cannot be reduced to compliance with particular requirements.  It is necessary to give genuine and proper consideration to all relevant considerations (Ferocem at IPR 247-8 and Goninan at IPR 220).
    • The reasons why the evidence was not served earlier are a relevant consideration, but a satisfactory explanation is not a mandatory requirement (Ferocem at IPR 247).
    • The public interest in determining a serious opposition on its merits is a relevant consideration.  In order to do this, the Commissioner must form a view as to the nature of the evidence that it is sought to adduce, and the significance of that evidence for the opposition proceedings (Goninan at 225-226).
    • The interests of the party seeking the exercise of the discretion are also a relevant consideration (Ferocem at IPR 247).
    • It is relevant to consider the disadvantage to the other party of delays in determining the opposition, and the effect of delays on the efficient and orderly administration of the Patents Office (Ferocem at IPR 247, Goninan at IPR 222).

  14. That is, the criteria to be considered arise from the need to balance a serious opposition being determined on its merits and determining an opposition as expeditiously as possible.

  15. In Transgene SA v Virax Holdings Ltd [2002] APO 14 (17 April 2002), the delegate considered that the relevance of evidence was a key factor that Sackville J in Goninan (supra) considered relevant in deciding whether evidence should be allowed:

    “In order for the Commissioner or his delegate to give proper, genuine and realistic consideration to the aspect of the public interest I have identified, it is necessary to consider the nature of the evidence the opponent seeks to adduce and the significance of that evidence for the opposition proceedings.”

  16. However, as Sackville J went on to explain, this does not mean that the evidence has to be scrutinized in the same way as would occur at a hearing on the merits.  Rather, it is necessary to form a prima facie view of whether the evidence is likely to be important in the opposition proceeding given the nature of the issues addressed by the proposed evidence. 

  17. Paragraphs 1 to 6 of Cameron #3 set out the basis and context of the application for leave to serve further evidence.  Paragraphs 7 to 17 of Cameron #3 relate to issues that had been raised in relation to the amendments.  As noted above, amendments were made to the specification following service of evidence in support.  The opponent submitted that these amendments resulted in a broadening of the scope of the claims, and the priority entitlement of the claims was challenged for the first time in evidence in reply.  Monsanto conceded at hearing that some “adjustment” of evidence may be required as a consequence, but submitted that leave should only be granted in issues relating to the amendments.  Accordingly I consider it appropriate to grant leave to file further evidence in this respect to these matters. 

  1. Paragraphs 20 to 22 and 51 to 54 of Cameron 3# relate to the issues of synergy, weed efficacy and crop selectivity.  These were key issues of contention at the hearing, and Syngenta relied upon the evidence of Mr Cameron to argue the meaning of such terms, and the unpredictable nature of the technology.  Quadranti provides evidence concerning the ED90 commercial standard for assessing the herbicidal activity of formulations.  Paragraphs 1 and 2 of Power simply note and correct typographical errors in Cameron #3.  Power paragraph 7 forwarded a review paper of herbicide tank mixtures (PAP-1) and a book extract (PAP-4) which was referred to in an EPO decision (PAP-3).  Syngenta relied upon the ED90 standard and exhibits PAP-1 and PAP-4 in their submissions at hearing in relation to inventive step and the analysis of test data.  Prima facie the nature and relevance of this material indicated that it could be relevant to a correct determination of the opposition, and I consider leave to serve further evidence may be granted in relation to these matters.

  2. Taking into account all the circumstances and given the prima facie nature and significance of the evidence sought to be adduced, I formally grant leave to serve further evidence in relation to paragraphs 1 to 17, 20 to 22 and 51 to 54 of Cameron 3#, Quadranti in its entirety and paragraphs 1, 2 and 7, and Exhibits PAP-1 and PAP-4 of Power.  I allowed Monsanto 1 month to serve evidence in response to the further evidence, and both parties made extensive written submissions in relation to the further evidence and evidence in response.

    The description

  3. Metolachlor is an important herbicide which is widely used, either alone or in combination with other co-herbicides, for the control of weeds in crops such as corn and soybean.  Metolachlor contains two elements of asymmetry: the first is located at the 1′-carbon atom of the 1′-methyl-2′-methoxyethyl group; and the second results from obstruction of the free rotation of the bond between the nitrogen and the phenyl radical (denoted as the “a” bond).  These elements of asymmetry result in four diastereomers, and herbicidal activity is greatest in the two diastereomers having the S-configuration at the 1′-carbon atom.  The herbicidal use of a mixture of these two diastereomers, namely aRS,1′S(-)-N-(1′-methyl-2′-methoxyethyl)-N-chloroacetyl-2-ethyl-6-methylaniline (hereinafter S-metolachlor), has been described in the prior art.   

  4. Research Disclosure No. 37242 (April 1995) discloses herbicidal compositions comprising racemic metolachlor in combination with other herbicides including atrazine, terbuthylazine, flumetsulam, pendimethalin, metolsulam, pyridate, glyphosate, glufosinate, cyanzine, dicamba, halosulfuron, prosulfuron, sulcotrione, metribuzin, and BAY FOE 5043; or a mixture of prosulfuron and primisulfuron.  The present invention relates to the preparation and use of compositions comprising S-metolachlor and these particular co-herbicides for the selective control of weeds in useful crop species.  Such compositions are purported to have a selective herbicidal action that is capable of effectively controlling weeds without considerably damaging useful crop species.  Furthermore, the compositions apparently have a “greater than expected additive action” against weeds, which allows for reduced rates of application, achieves control of weeds where the individual herbicides are not effective, and provides increased selectivity for cultivated plants. 

  5. The compositions of the invention are said to be suitable for all conventional application methods, for example pre-emergent or post-emergent application or seed dressing.  The description provides a number of examples comprising a pre-emergent herbicidal treatment.  The invention also includes methods wherein S-Metolachlor and the co-herbicide are applied separately at different times.  Such methods are illustrated by sequential pre-emergent treatment with S-metolachlor immediately following sowing, with subsequent post-emergent treatment using the second herbicide at the 2- to 3-leaf stage of plant growth.  Consequently, where reference is made to the use of compositions according to the invention, this may be taken to be inclusive of those methods in which the components are applied separately.  

  6. The specification provides various formulation examples, including emulsifiable concentrates, solutions, wettable powders, granulates, dusts and suspension concentrates. The herbicidal activity of the compositions comprising S-metolachlor is compared with corresponding compositions comprising racemic metolachlor, and further comparative results were provided by Syngenta in evidence in answer. 

    The claims

  7. The specification ends with 7 claims, as follows.

    (1)       A herbicidal composition which comprises:

    as a first component, aRS,1′S(-)-N-(1′-methyl-2′-methoxyethyl)-N-chloroacetyl-2-ethyl-6-methylaniline, of the formula A

    (A)

    which is substantially free of the other isomers, and

    as second component, a compound selected from the group consisting of atrazine, terbuthylazine, flumetsulam, pendimethalin, metolsulam, pyridate, glyphosate, glufosinate, cyanzine, dicamba, halosulfuron, prosulfuron, sulcotrione, metribuzin, and BAY FOE 5043; or a mixture of prosulfuron and primisulfuron, wherein the compound of formula A and the second component are present in a weight ratio of 1:10 to 1:0.001.

    (2) A synergistic herbicidal composition, substantially as hereinbefore described with reference to any one of the Examples.

    (3)A method of controlling undesirable plant growth in crops of useful plants, which comprises exposing the crop plant or its environment to a herbicidally active amount of a composition according to claim 1 or claim 2.

    (4)The method according to Claim 3, wherein the exposure of the crop plant or its environment to the compound of the formula A is separated in time from exposure to the second component.

    (5)The method according to claim 3 or claim 4, wherein the crop plant is a cereal, rice, oilseed rape, sugar beet, sugar cane, a plantation crop, cotton, maize or soybean.

    (6)       The method according to claim 5 wherein the crop plant is maize or soy bean.

    (7)The method according to any one of claims 3 to 6, wherein the crop plant is treated with the composition according to claim 1 or claim 2 at rates of application which correspond to 0.3 to 4.0kg of the total amount of active ingredient per hectare.

    DECISION

    Priority

  8. The priority date of a claim is the date that the subject matter of the claim was first disclosed.  In general this will be either the filing date of the priority document, the filing date of the complete specification, or the filing date of the proposed amendments (section 114(1) and regulation 3.14).  The priority entitlement of the present claims was disputed by Monsanto on the basis that the amendments during opposition introduced new matter that could only be afforded the priority date of its filing.

  9. The first amendment, dated 21 March 2002, incorporated the following features into Claim 1:

    ·   the expression “which is substantially free of the other isomers”

    ·   the requirement that “the compound of formula A and the second component are present in a weight ratio of 1:10 to 1:0.001”.

  10. The second amendment, dated 21 May 2003:

    ·amended the reference in Claim 1 to “the compound of formula A” to include the chemical name of S-metolachlor

    ·amended the description to include that “(a) process for the preparation of this compound which can be used on an industrial scale has been described, for example in WO 95/21151, published 10 August 1995”.  This publication post-dates the priority date of the present claims.

  11. Monsanto claimed that the specification as filed did not state the purity of S-metolachlor, and that it “could therefore be reasonably concluded on a fair reading of the specification that the claimed herbicidal composition included S-metolachlor which was optically pure.”  Monsanto submitted that the first amendment resulted in a relaxation of the requirement that S-metolachlor was optically pure, since as a result of amendment it now needed only to be “substantially free” of the other isomers.  Monsanto considered that the basis for the amendment was reference to US 5002606 in the specification, and conceded that the term “substantially free of the other isomers” was imported directly from this reference.  However, they submitted that S-metolachlor in this citation had an optical purity of about 98%, so that if this was taken to illustrate the optical purity then the specification as filed had support only for this level of purity.  Subsequent amendment to include a reference in the description to WO 95/21151, which describes the preparation of a product having an optical purity of about 80%, was claimed to broaden the claims from having minimal impurities (approximately 2%) to having impurities in the order of 20%.

  1. This submission relies on Claim 1, when properly construed, either explicitly or implicitly defining the degree of purity of the particular enantiomer in the manner asserted by the opponent (Emory University v Biochem Pharma Inc., 39 IPR 603). The principles of construction are well established, and were summarised recently (Sachtler GmbH & Co KG v RE Miller Pty Ltd [2005] FCA 788 at [39]-[42]). The claim as filed defined S-metolachlor without any further indication of optical purity. Indeed, I note that prior to amendment of Claim 1 to further define that S-metolachlor was “substantially free of the other isomers,” the opponent’s experts interpreted the claim to include racemic metolachlor. While the specification provides no explicit indication of the optical purity of S-metolachlor that can be used in the formulations, the reference to the prior art is clearly intended to be illustrative of one way in which S-metolachlor may be obtained.

  1. The key question is what would the person skilled in the art understand the language of the claim to mean.  A purely literal interpretation of the term “S-metolachlor” would require 100% purity in the manner suggested by the opponent.  However, in practice it is unlikely that a compound would be obtained in such a level of purity, and the general understanding would be that the compound is in an enantiomerically enriched form.  Amendment of the claim to include the requirement that S-metolachlor is “substantially free of the other isomers” is consistent with this accepted meaning.  Furthermore, Mr Cameron stated that he understood the claim to mean that the other isomers were excluded from the composition, but that minor or trace amounts of these isomers could be present.  Rather than placing a numerical value on the meaning of “trace or minor”, Mr Cameron considered that the impurities were in an amount that did not have any substantial or significant material effect on the overall properties of the herbicidal composition (Cameron #3).  However, Mr Brinker asserted that the term “minor or trace” limited the impurities to the order of 1%, and further asserted that it was not possible from a reading of the specification to determine whether an impurity had a material effect on the overall properties.

  1. I consider the interpretation provided by Mr Cameron is consistent with the principle that patent specifications should be given a purposive construction.  Whilst the terminology may be imprecise, the skilled person would take the claim to mean that the S-metolachlor to be used in the formulation is of a purity that is suitable for the intended use (Minnesota Mining and Manufacturing Co v Beiersdorf (Australia) Ltd 144 CLR 253 at 274). Therefore, I consider that neither amendment resulted in the claiming of matter that was not in substance disclosed in the specification as filed. As an aside, I note that Dr Preston referred to the prior art document LeBaron et al., Herbicides: chemistry, degradation, and mode of action, Volume 3, 1988 (CP-7) in his evidence in support. This document discloses S-metolachlor having approximately 85% optical purity, and the indication is (and this was not questioned by Dr Preston in his reference to the enantiomers) that such purity is considered suitable for herbicidal use and assessment as an enantiomerically-enriched composition.

  2. Monsanto also submitted that Claim 1 is not entitled to claim priority from the Swiss basic document as it is not limited to compositions having S-metolachlor in combination with a “synergistically effective” amount of a co-herbicide, as purportedly required by the basic document.  Similarly Claim 2 was alleged not to have entitlement from the Swiss basic document as the compositions are defined with reference to tables 1 to 19, but these tables were not specifically disclosed in the basic document. 

  3. The Swiss priority document discloses compositions comprising S-metolachlor together with a broad range of co-herbicides, and specifically defines the use of synergistic amounts of the co-herbicides in the formulation.  Each of the herbicides claimed in the present claim is named in the provisional application.  The basic document does indeed describe the use of a synergistic amount of the co-herbicide, and this is a limitation that is not specifically defined in present Claim 1.  However, while the claims of the complete specification do not specifically define “synergy”, the properties of the compositions (herbicidal activity, weed spectrum, selectivity) are described in the same manner as the complete application, and the indication is that these are inherent properties of the compositions.  Accordingly, I consider that there is a real and reasonable disclosure of the invention as claimed in the basic application, and consequently the present claims are entitled to the priority date of the Swiss basic application.

    Novelty

  4. Monsanto submitted that as the claims were not entitled to the priority date of 12 April 1995, several documents published after this date became relevant for the purpose of determining novelty.  These included the present application as filed and as accepted.  I have found that the claims are entitled to the earliest priority date, so I need not consider this submission any further.  However, I do note that in previous decisions similar submissions have been found without basis.  For example in The Regents of the University of California v The Dow Chemical Company [2001] APO 34 (26 July 2001) the delegate noted that:

"Although the tests for novelty and fair basis are not the same I cannot agree with ...[the] argument. The disclosure in the specification which is sought to be used of the purpose of novelty,..., also serves to support for the claims in so far as fair basis is concerned. Thus, whatever is fairly based cannot be held not novel and whatever is not fairly based cannot be used as an anticipation."

  1. Monsanto also submitted that the definition in Claim 2 of herbicidal compositions with reference to the examples resulted in the claiming of comparative compositions containing racemic metolachlor.  However, such omnibus claims are generally construed as being broadly limited to the essential features of the invention described in the examples, and prior art examples are taken to be outside the scope of the claims on the basis that this would be an absurd result (Henriksen v TallonLtd [1965] RPC 434). Accordingly, I consider that Claim 2 does not include compositions comprising racemic metolachlor, and is novel in view of the prior art.

    Inventive step

  2. In the case of applications filed prior to 1 April 2002, a claimed invention will lack inventive step if it is obvious in view of:

    (a) common general knowledge; or

    (b)common general knowledge considered together with information in a single document or through doing a single act, provided that the document or act could reasonably be expected to have been ascertained, understood and regarded as relevant to work in the relevant art in the patent area by the person skilled in the art.

  3. At hearing Monsanto made submissions in relation to the following:

·     Common general knowledge alone.  This submission is based on S-metolachlor and compositions comprising metolachlor and a co-herbicide being common general knowledge.

·     Documents disclosing compositions comprising racemic metolachlor and particular co-herbicides, which Monsanto submitted would be combined with the common general knowledge of S-metolachlor and its increased herbicidal activity over the racemic mixture.  This submission does not require compositions comprising metolachlor and particular co-herbicides to be common general knowledge, but is based on S-metolachlor being common general knowledge. 

·      Documents disclosing S-metolachlor and its use as an herbicide, which Monsanto submitted would be combined with the common general knowledge of compositions comprising racemic metolachlor and a co-herbicide.  This submission does not require S-metolachlor to be common general knowledge, but is based on compositions comprising racemic metolachlor being common general knowledge.

Were compositions comprising racemic metolachlor common general knowledge?

  1. Metolachlor was first described in 1972, and is particularly useful for the control of grass weed species.  It has been widely used for selective control of weeds in more than 70 crops worldwide (Exhibit JC-2), and by 1998 was one of the most widely used herbicides in soybean and maize crops.  Metolachlor is often used in combination with broad-leaved herbicides to extend the spectrum of activity, and is apparently compatible with most other herbicides.  The evidence included citations describing various compositions of metolachlor with other herbicides dating back to 1980 (Exhibits BSW-8 to 28).  Moreover, compositions comprising metolachlor and a co-herbicide (including some of those named in the present claims) had been marketed at the priority date of the present application.  The Herbicide Handbook Seventh Edition, (Exhibit CP-2) discloses that metolachlor has been used commercially with various other herbicides, including atrazine (BICEPÒ), cyanazine (CYCLEÒ), flumetsulam (BROADSTRIKE + DUALÒ) and metribuzin (TURBOÒ 8EC).  The Australian Weed Control Handbook, Eighth Edition, 1987 discloses that metolachlor is formulated with atrazine in the products GESAPRINÒ (Exhibit CP-3) and Primextra (Exhibit CP-4).  As these are commercial products and the citations are standard references in the art, there is a strong indication that this matter would be widely accepted by those in the art and constitute common general knowledge.  This was not disputed by the parties, and I accept that compositions comprising racemic metolachlor and a co-herbicide were common general knowledge.

Was S-metolachlor common general knowledge?

  1. The four individual diastereomers of metolachlor were first described by Moser et al. “Atropisomerism, Chiral Centre and Activity of Metolachlor” Pesticide Chemistry: human welfare and the environment. Vol. 1 (Exhibit BSW-7) in 1983.  This citation also described the superior herbicidal activity of the two individual S-enantiomers in comparison with the R-isomers and the racemic mixture.  Around the same time, a mixture comprising the two S-enantiomers, S-metolachlor, was the subject of US 5002606 (BSW-6).  This citation noted that S-metolachlor has improved activity and crop selectivity when compared with the racemic compound.  In particular, S-metolachlor is apparently better tolerated by maize and soybean, and also stimulates the root growth of germinating plants.   The evidence included a further document: LeBaron (Exhibit CP-7) which describes a comparative study of the effect of metolachlor, R-metolachlor and S-metolachlor on the growth of oat roots.  Contrary to the observations in US 5002606, root growth stimulation by S-metolachlor was essentially the same as the racemic mixture. 

  2. A commercially applicable synthesis was not published until after the priority date of the present application (WO 95/021151).  S-metolachlor was eventually registered in Australia for commercial use in 1999, some 4 years after the priority date of the present application.  Prior to the present application, there was no disclosure or suggestion in any document of compositions comprising S-metolachlor and a co-herbicide. 

  3. Monsanto asserted that S-metolachlor was common general knowledge, noting that Dr Preston referred to US 5002606 as a “basic disclosure in relation to a most significant herbicide” (Preston #1), which he and other persons skilled in the art regularly consulted.  However, it was not clear from Dr Preston’s declaration whether such interest was of an academic nature (such as the different activities shown by various enantiomers), or whether S-metolachlor was viewed at the relevant time as a potential commercial herbicide which was suitable for formulation with other herbicides.  In this regard, it is not sufficient that a document pique the interest of a researcher in order to be considered common general knowledge, and while I accept that S-metolachlor was public knowledge there is no evidence before me to establish that the matter disclosed in US 5002606 formed part of the common general knowledge in the field of herbicide formulation. 

    What documents can be relied on?

  4. I have found that the opponents have not adequately shown that S-metolachlor was common general knowledge in the field of formulation chemistry at the priority date of the present application.  Therefore the opponent’s submissions in relation to common general knowledge alone, and in relation to S-metolachlor as common general knowledge cannot be sustained.  As a consequence the only relevant consideration is that documents disclosing S-metolachlor would be combined with the common general knowledge of formulation comprising racemic metolachlor and a co-herbicide.  Monsanto submitted that two documents disclosing S-metolachlor were of relevance in this regard, namely Moser et al. (BSW-7) and US 5002606 (BSW-6).

    Is the invention obvious?

  1. The gist of the argument presented by Monsanto is that it would be obvious in view of these documents to use S-metolachlor in place of racemic metolachlor in known herbicidal formulations.  Monsanto asserted that because S-metolachlor was more active than racemic metolachlor any synergistic interactions in formulations comprising metolachlor and a co-herbicide would be expected to occur at lower concentrations with S-metolachlor.  This is a relatively strong prima facie case, but in my opinion the evidence provides several key points that indicate that the present invention is not obvious.

  1. The evidence indicates that S-metolachlor was still an “experimental” herbicide at the priority date and a commercial synthesis was yet to be developed at the priority date of the present application.  Indeed, even as late as 1998 (about 3 years after the priority date of the present application), a review discussing the development of S-metolachlor indicated that field trials to fully determine the herbicidal properties of S-metolachlor had only been performed at or after the priority date.  The herbicidal and broad acre properties of S-metolachlor were yet to be determined, and in the absence of such there was no reasonable likelihood of success to motivate the skilled person to formulate S-metolachlor with other co-herbicides.  In my opinion the opponent’s submissions appear to be an ex post facto analysis, and there is insufficient evidence to establish that a formulation chemist would use a product for which herbicidal properties were yet to be determined, or for which the costs of production may outweigh any perceived benefits of superior herbicidal activity.

  1. Monsanto further submitted that synergy was the rule rather than the exception when metolachlor was mixed with other herbicides.  This being the case, there is insufficient evidence to show that a skilled formulation chemist would be directly led to use S-metolachlor when a number of other equally as promising, and commercially available, alternatives existed.  The opponent’s argument appears to be one of “obvious to try”, a test that was ruled in the High Court to be an impermissible test for obviousness (Aktiebolaget Hassle v Alphapharm Pty Ltd supra). The High Court cited In re O’Farrell with favour:

    “[F]or many inventions that seem quite obvious, there is no absolute predictability of success until the invention is reduced to practice.  There is always at least a possibility of unexpected results, that would then provide an objective basis for showing that the invention, although apparently obvious, was in law unobvious.”

  2. An “obvious to try” situation might arise where further research might be done as a result of a disclosure, but the disclosure does not provide sufficient teaching of how to obtain the desired result, or that the claimed result would be obtained if certain directions were pursued.  The formulation of S-metolachlor with the various co-herbicides of the present claims may be obvious to try, but there is no evidence before me that establishes that the skilled person would be directly led to do so.  

  3. Even if a formulation chemist was eventually led to formulate S-metolachlor with other co-herbicides, the evidence suggests that the properties of the resulting compositions could not be predicted, and indeed teaches away from the present invention.  When herbicides are used in combination the resulting compositions exhibit one of three properties: there may be a synergistic, antagonistic, or additive effect.  Apparently the properties of herbicidal combinations can be difficult to predict since the behaviour of each co-herbicide is often affected by the presence of the other.  Monsanto submitted that synergistic interactions would be expected to occur at lower concentrations with S-metolachlor, and presumably antagonistic interactions would similarly be expected to occur at lower concentrations.  No corroborative evidence was provided in support of this assertion, but in any case the evidence shows that formulations comprising racemic metolachlor and atrazine, metosulam, cyanazine, prosulfuron or dicamba exhibit antagonism (this is apparent from the decrease in herbicidal activity that occurs when the co-herbicide is present), while the corresponding compositions comprising S-metolachlor show increased herbicidal activity (Flattery Declaration VI).  If the opponent’s submission that biological effects are enhanced in enantiomers is correct, it is unlikely that the skilled person would be led to use a compound where increased antagonism could have an adverse effect on herbicidal activity.

  1. Therefore the opponent has not established that any of the claims lack an inventive step based on the common general knowledge alone, or in combination with any of the above documents.

    SECTION 40

    Clarity

  2. Claim 4 defines a method of treatment in which a crop is exposed to “compositions” wherein S- metolachlor and the co-herbicide are applied separately in time.  This was not raised in the opponent’s written submissions, but was mentioned briefly at hearing.  Clearly a composition in which the components are intimately mixed cannot be applied in such a manner, and the intention is to define methods such as the exemplified combination of pre- and post-emergent herbicidal treatments.  I consider this a relatively minor matter that does not invalidate the patent.

Synergy and fair basis

  1. The question of whether or not synergy was an essential feature of the invention, and whether such a property had been properly demonstrated, was a key issue between parties as it potentially impacted on fair basis.  In particular, Monsanto submitted that a reference in the specification to a “greater than expected additive action” indicated that the compositions of the invention had synergistic properties.  They applied a narrow interpretation of the term synergy, arguing that synergy related only to the level of herbicidal activity.  Monsanto argued that as a consequence the claims were too broad because not all compositions exhibited the narrowly construed synergy.

  2. Syngenta applied a broad interpretation of the term synergy, arguing that it “does not matter what label is used to refer to the beneficial properties seen in the claimed compositions.”  Moreover, Mr Cameron stated that synergy could be in relation to crop selectivity as well as herbicidal activity (Cameron #1), and the compositions of the invention exhibited “synergy” in relation to both of these effects.

  1. The specification describes the use of a combination of herbicides which “is suitable for selectively controlling weeds in crops of useful plants” (see for example page 1, lines 1 to 3).  The properties of the compositions appear to be consistent with synergy (“the rates of application of the single compounds are reduced while the effectiveness is retained”), and with selectivity (“an additional increase in the selectivity for the cultivated plants that is necessary and desirable in the event of unintentional over application of herbicide”).  Furthermore, comparative results provided in Tables 1 to 19 show that the compositions achieve control of most weed species without significant crop damage against maize at a range of application rates.  Therefore, on a reading of the specification as a whole a broader interpretation of the term “synergy” to include increased crop selectivity in addition to increased herbicidal activity is appropriate, and I consider the claims are fairly based in this regard.

    Manner of Manufacture

  2. Monsanto submitted that the invention is no more than the new use of a combination of known herbicides to control weeds in known plants in a manner for which the known properties of those herbicides make them suitable, and that the invention did not possess the quality of inventiveness to be patentable.  However, the present claims do not relate to the new use of a known composition as the compositions are novel.  I have also found that the compositions are inventive.  Consequently this ground of opposition fails.

    Conclusion

  1. The opponent has not established that the claims lack novelty or inventive step in light of any of the documents, or in the case of inventive step, in light of the common general knowledge in the art alone, or in combination with any one of the documents.  All of the claims are fairly based and define a manner of manufacture.  The opposition has been unsuccessful in respect to these matters.

    Costs

  1. Both parties submitted that costs should follow the event.  As the opponent has been unsuccessful on all grounds of its opposition, I award costs in accordance with Schedule 8 against Monsanto.

    Delegate of the Commissioner of Patents
    L. F. McCaffery
    21 April 2006

    Patent attorneys for the applicant  :  Spruson & Ferguson

    Patent attorneys for the opponent  :  E. F. Wellington & Co.

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Emory University v Biochem Pharma Inc. [1999] APO 50
Emory University v Biochem Pharma Inc. [1999] APO 50
Ferocem Pty Ltd v Commissioner of Patents [1994] FCA 981