Virbac S.A. v American Home Products Corporation and Merial Australia Pty Limited

OFFICIAL NOTICE
DECISION OF A DELEGATE OF THE COMMISSIONER OF PATENTS
Application : No. 691990 in the name of Virbac S.A.

Title: Equine anthelmintic formulations

Action: Two oppositions to the grant of a patent by American Home Products Corporation and Merial Australia Pty Limited

Decision: Issued
Abstract

The oppositions succeed on the basis of lack of inventive step and a minor section 40 matter. There is also a lack of entitlement in relation to a third inventor.
(i) The description: The specification describes the invention as the use of a combination of two anthelmintic agents. This achieves a broad spectrum of activity. The specification provides data that indicates that there is a synergy between the two agents. While this result is different to that reported in an earlier journal article, there is no evidence that synergy does not occur.
(ii) The claims: The claims are directed to a treatment -
* that is effective, without necessarily achieving 100% efficacy;
* for horses that might be infected with A. perfoliata;
* in an amount effective against A. perfoliata; and
* that does not have to involve synergy.

Ambiguous terminology was interpreted by having regard to the description.
(iii) Novelty: The invention is novel because the Sankyo patent discloses similar, but not the same, compositions. Suggestions in the citation of other things that could be done were not sufficiently disclosed.
(iv) Inventive step: The problem was to produce a treatment of animals infected with both roundworms and tapeworms. Enhanced activity against A. perfoliata was found to be a bonus.
* There is no inventive step in the light of the common general knowledge alone as it would have been routine to select praziquantel and an avermectin or milbemycin, and adjust the dosage of the active agents.
* There is no inventive step in the light of the Lyons article as it would have been routine to include an avermectin or milbemycin, and adjust the dosage of the active agents.
* There is no inventive step in the light of the Bayer patent as it would have been routine to include an avermectin or milbemycin, and adjust the dosage of the active agents.
* There is no inventive step in the light of the Sankyo patent as it would have been routine to apply the composition to horses and make the necessary adjustment in the dosage of the active agents.

(v) Other matters:
* It is likely that Mr Harvey’s proposal was an input to the development of the composition. It is improbable that Example 4 of the invention would have occurred without the input of Mr Harvey, making him a joint inventor.
* While the exact nature of the composition contributes to the exact level of performance, it is not necessary to define the other components in order to predict that the composition will have a broad spectrum activity.

PATENTS ACT 1990
DECISION OF A DELEGATE OF THE COMMISSIONER OF PATENTS
Re:Patent Application No. 691990 by Virbac S.A., and two oppositions to the grant of a patent by American Home Products Corporation and Merial Australia Pty Limited

BACKGROUND

Patent application number 39087/95 was filed by Virbac S.A. (hereafter referred to as Virbac) on 28 November 1995. The application is associated with provisional application PM 9699 (filed on 28 November 1994). The application was examined by the Commissioner, and advertised accepted under the serial number 691990 on 28 May 1998.
American Home Products Corporation (hereafter referred to as AHPC) filed a notice of opposition on 27 August 1998. A statement of grounds and particulars was served on 26 November 1998. The evidence stages were completed on 26 October 2001.
Merial Australia Pty Limited (hereafter referred to as Merial) filed a notice of opposition on 28 August 1998. A statement of grounds and particulars was served on 27 November 1998. The evidence stages were completed on 30 January 2002.
Both opponents opposed the grant of a patent on the following grounds:
* novelty
* inventive step
* manner of manufacture
* section 40
The evidence in support of the AHPC opposition consisted of declarations by Michael James Caine (2 declarations), Guang Tsan Wang (2 declarations), Roger L DeLay, John Arundel and Ian Beveridge. The evidence in answer consists of declarations by Joseph C Boray, Paul John Martin, Vincent Beuvry and David James Jenkins. Evidence in reply consists of declarations by Guang Tsan Wang, John Henry Arundel, Ian Beveridge, James Lindsay Duncan, Ramune M. Cobb and Joseph Owen Douglas Slocombe.
The evidence in support of the Merial opposition consists of declarations by Andrew Warren Lee and Peter F. Rolfe. The evidence in answer consists of declarations by Joseph C. Boray, Paul John Martin, Vincent Beuvry and David James Jenkins. Evidence in reply consists of declarations by Peter F. Rolfe and Paul Anthony Kilborn.
Prior to the hearing I informed all parties that I had become aware of a declaration by Michael Ffloyd Forster that was served in evidence in an action on petty patent number 711820. Mr Forster is an inventor of the present application, and his declaration related (in part) to the present application. At the hearing I directed that all parties could serve further evidence in relation to the matters raised in the Forster declaration. Declarations were served by Vincent Beuvry and William J Blackhall.
The oppositions were heard concurrently in Sydney on 1 to 3 July 2002. Virbac were represented by Dermot Ryan of counsel assisted by Julian Blenkinship of Barker, Blenkinship & Associates. AHPC were represented by Bruce Caine of counsel assisted by Michael Caine of Davies Collison Cave and Anthony Muratore of Freehills. Merial were represented by Ben Fitzpatrick of counsel assisted by Paul Kilborn of F.B.Rice & Co. Also present were Rob Barclay (of Fort Dodge Australia Pty Ltd), Ramune Cobb (of Fort Dodge Animal Health), Barbara Renda (of American Home Products Corporation), Sally Mannion (of Wyeth Laboratories).
Mr Bruce Caine made oral submissions on behalf of AHPC in relation to all of the grounds of opposition, supported by written submissions. The grounds of novelty and inventive step were based on a small selection of the documents that were identified in the statement of grounds and particulars. It is fair to say that the major issue is the ground of lack of inventive step. Mr Fitzpatrick made oral submissions on behalf of Merial which were supported by written submissions. As the case of Merial was largely the same as that of AHPC, Mr Fitzpatrick adopted many of the submissions made by Mr Caine, in order to avoid unnecessary repetition. Mr Ryan responded to both sets of submissions in a brief oral submission, supported by written submissions.
THE SPECIFICATION
1. The description
The specification relates to the treatment of parasitic infestations in equine animals (especially horses). The specification is specifically concerned with parasitic intestinal worms (helminths). It is agreed between the parties that horses are prone to infection by three principal types of worms: nematodes (commonly known as roundworms), cestodes (commonly known as tapeworms) and trematodes (commonly known as flukes). It is clear from the specification that one of the major tapeworms of horses is Anoplocephala perfoliata.
The first sentence of the specification specifies that the invention relates to “the simultaneous treatment of roundworms and tapeworms”. The specification acknowledges that avermectins and milbemycins have been used in the control of roundworms, but are inactive against tapeworms. Avermectins and milbemycins collectively belong to a class of compounds known as macrocyclic lactones. The specification goes on to state that it would be desirable to prepare “a formulation which has activity against cestodes and nematodes infestation in horses” (page 1A, paragraph 4). The solution is presented as a specific combination of praziquantel with either an avermectin or milbemycin. On page 2, the specification states that such a composition has a surprising increase in the anthelmintic spectrum, and also demonstrates a synergistic effect:
“Trials have indicated that Praziquantel in combination with an Avermectin or a Milbemycin has been administered with a surprising increase of the anthelmintic spectrum due to the administration in combination. Furthermore a synergistic effect has been observed to the extend (sic) that when in combination with Avermectins or Milbemycins the required dosage rate for Praziquantel in equine animals is between 0.5 and 2.0 mg/kg. This synergistic activity observed was even higher with a paste formula.”
[page 2, paragraph 1]
At page two, the specification goes on to refer to the prior art. Praziquantel in combination with another anthelmintic agent is disclosed in GB 2252730. These compositions are not synergistic and are only used in sheep. The amount of praziquantel recommended for use is 2.0 to 7.5 mg/kg. Macrolide anthelmintics (a term that covers both avermectins and milbemycins) in combination with other anthelmintics are disclosed in EP 59074. These compositions are not synergistic in association with A. perfoliata.
The specification then recites suitable avermectins and milbemycins, and suitable ingredients that can be included in the composition. Nine compositions are exemplified, and two trials in horses are reported. The trials indicate that synergy is achieved with dosages below the claimed dosage range of praziquantel, but the efficacy is very low (0.1 mg/kg still demonstrated synergy, but the efficacy was only 39%; see Example 10). Dosages above the claimed dosage range of praziquantel give 100% efficacy, so higher dosage does not lead to a better product (see Example 10). The choice of 0.5 to 2.0 mg/kg appears to be based on achieving a useful efficacy as evidenced by Example 10.
2. How does the invention work - is there synergy?
There is a marked difference of opinion between the declarants as to whether there is a synergy between the praziquantel and the avermectin or milbemycin. There is agreement between the parties as to the meaning of synergy, and for convenience I will refer only to the definition provided by Dr Rolfe in his declaration in support of the Merial opposition (Mr Beuvry agreed with this definition: see his declaration in answer to the Merial opposition, paragraph 17):
“Synergy can be defined as the effect of two chemicals being greater when used together as compared to the additive effect of the chemicals when used alone.”
[paragraph 32]
The difference of opinion is based on what evidence should be considered to demonstrate synergy. On the one hand, the declarants for Virbac point to the examples in the specification, which show that a combined treatment with praziquantel and abamectin or ivermectin gives an efficacy that is greater than would be expected from the efficacy of the components individually. It is clearly correct that the data on the face of the specification is consistent with synergy. On the other hand, the declarants for the opponents point out that a 1 mg/kg dosage of praziquantel alone was investigated in the prior art by Lyons, and found to be highly effective (this article is discussed more fully under the heading of inventive step). Their conclusion is that the efficacy of the combined treatment is due to the praziquantel alone, and not due to synergy (and that the experiments that demonstrate synergy are not reliable). I note that no experimental data has been provided to show that the results reported in the specification of a synergy between praziquantel and abamectin or ivermectin are not reproducible. Dr Rolfe suggested that this was due to ethical concerns (Rolfe declaration in reply to the Merial opposition, paragraph 49), but it remains a fact that the synergy result has not been shown to be non-reproducible.
The key to this dispute is whether the difference between the Lyons results and the present specification indicates an error in the present specification, or is a legitimate variation. It is recognised that the results obtained depend on a range of factors, including the time of year, the exact nature of the composition, and the number of parasites in each horse. It seems to me that results are only comparable if carried out under substantially identical conditions. It is not clear if the Lyons work was done under the same conditions as the present specification, so it would appear to be unsafe to compare the absolute values of the results, as against the principle that praziquantel is a useful agent against A. perfoliata in horses. The results reported in the present specification are internally comparable if the tests were all done under the same conditions. There is no information in the specification as to whether this is the case, but it is a reasonable presumption that they were carried out under the same conditions. As already noted, the data in the specification supports a conclusion of synergy between praziquantel (used in the range of 0.5 to 2 mg/kg) and abamectin or ivermectin.
A large number of comments are made in the evidence about the quality of the data in the specification, and whether it would have been accepted for publication in a scientific journal. The data in a patent specification is assessed solely against the standard imposed by the Patents Act - is it sufficient to provide full description of the invention, a best method of performance and fair basis for the claims. If an applicant decides to omit technical information from their patent specification, they accept the risk that their application may be refused if it results in the failure to meet one of the criteria.
3. The claims
The specification ends with eight claims. Claim 1 is an independent claim, and the remaining claims are dependent claims. The claims are listed in full in the Annex.
The claims are directed to the use of a composition, and not to the composition per se. In brief, claim 1 is directed to a method of treating equine animals by administering a specified composition of praziquantel and an avermectin or milbemycin. Claims 2 to 4 limit the anthelmintic agent to an avermectin only. Claims 3 and 4 require the avermectin to be abamectin and ivermectin respectively. Claim 5 limits the anthelmintic agent to the milbemycin known as moxidectin. Claims 6 and 7 limit the dose of the particular avermectin in claims 3 and 4 to about 0.2 mg/kg. Claim 8 limits the composition to a paste form.
There are several terms in claim 1 that require close scrutiny in order to appreciate the scope of the claim.
(i) A method for controlling and treating
The claim is a method for “controlling and treating” infestations of A. perfoliata. The question to be answered is what degree of efficacy is necessary in order to meet the requirement of “controlling and treating”. The term could be construed as complete efficacy (elimination of 100% of A. perfoliata), or a lesser but still substantial efficacy.
The starting point is to ask whether this term has a plain meaning to the skilled addressee. The declarants provided evidence as to their understanding of the meaning of the expression. Dr Boray seems to believe that the product will achieve 100% efficacy (Boray declaration in answer to the AHPC opposition, paragraph 13; Boray declaration in answer to the Merial opposition, paragraph 6(e)), which implies that this is how he construes the claim. This is consistent with his view that complete efficacy is necessary for an effective treatment:
“The control of A. perfoliata is difficult, due to the complicated life cycle involving oribatid mites as intermediate host. Complete clearance of the parasites is desirable to eliminate the contamination of the pasture with eggs of the tapeworm”
[Boray declaration in answer to the AHPC opposition, paragraph 5; a similar statement appears in the Boray declaration in answer to the Merial opposition, paragraph 5(b)]
On the other hand, Dr Wang drew a distinction between treatment and complete efficacy (Wang declaration in reply to the AHPC opposition, paragraph 11). This is consistent with Dr Arundel’s view of the practicalities of treating A. perfoliata:
“I believe it is probably impossible to eradicate A. perfoliata because of the complicated life cycle with the intermediate stages in pasture (Oribatid) mites. … However, the infection is not sufficiently serious that anyone would try to eradicate the worm. Control of worm numbers is all that is required.”
[Arundel declaration in reply to the AHPC opposition, paragraph 17]
I conclude that there is no single plain meaning for the expression, so I am left with an ambiguity.
In order to resolve this ambiguity it is legitimate to refer to the description for assistance (see Interlego AG v Toltoys Pty Ltd (1973) 130 CLR 461 at 476).
The specification demonstrates the efficacy of several compositions according to the invention:
Trial 1

Praziquantel (mg/kg) Abamectin (mg/kg) Efficacy against A. perfoliata

0.5 0.2 89

1 0.2 100

2 0.2 100

Trial 2

Praziquantel (mg/kg) Ivermectin (mg/kg) Efficacy against A. perfoliata

0.5 0.2 68

1 0.2 91

2 0.2 100

All of these compositions are according to the invention as described and claimed. It is clear from the specification that an efficacy as low as 68% is achieved by using compositions of the invention, so it is reasonable to infer that this is a satisfactory efficacy that should be regarded as a control or treatment of A. perfoliata. In broad terms, the specification is concerned with achieving a significant level of treatment, and is not restricted to complete removal of the parasite. I consider that the claim should be construed in the same terms.
(ii) Animal to be treated

The method of the claim is to administer the composition to “said animals”, which necessarily means equine animals infected with A. perfoliata. As a purely literal matter this is straight forward. The difficulty lies in the practical question of how do you identify an equine animal infected with A. perfoliata. The specification provides no suggestion of how to identify such an animal, and the examples of testing the composition simply used horses from an area where A. perfoliata was known to be prevalent. The horses were found to be infected with a number of types of parasites.
It appears to me that the compositions are intended to be used in a therapeutic and prophylactic manner, and the animals to be treated are any equine animals suspected of being infected with worms (being either roundworms or tapeworms, or both) or at risk of becoming infected. This is consistent with the usage instructions for the commercial product EQUIMAX. EQUIMAX is a composition of praziquantel and abamectin that is marketed by Virbac. The product is marketed for the control of a wide range of parasites, including A. perfoliata. The dosage rate is 2.5 mg/kg of praziquantel and 0.2 mg/kg of abamectin. The instructions for use are found in Exhibit GTW-5 to the first declaration in support of Dr Wang, and in Exhibit PFR-8 to the declaration in support of Dr Rolfe. The instructions state, inter alia:
“All horses should be included in a regular parasite control programme with particular attention being paid to mares, foals and yearlings. Foals should be treated initially at 6 to 8 weeks of age, and routine treatment repeated as appropriate.”
I conclude from this that in normal usage a composition of the type claimed in claim 1 would be used for the control of worms generally, and that no effort would go into selecting an animal specifically infected with A. perfoliata.
(iii) Effective dose
The claim refers to the composition containing an “effective dose of an anthelmintic agent selected from avermectins or milbemycins”. The question in relation to the dose is “effective for what end”? There are two obvious possibilities: an amount effective to produce high efficacy against A. perfoliata, or an amount effective to produce high efficacy against roundworms.

Looking solely at the claim, the words used clearly state that it is a method for the treatment of A. perfoliata. This means that the dose would be effective in achieving this end. To my mind, this is enough to resolve the matter. I note that Dr Jenkins (a declarant for Virbac) declared that he understood the term to mean effective for the removal of A. perfoliata (Jenkins declaration in answer to the AHPC opposition, paragraph 45).
Unfortunately, the plain meaning is not the meaning that the applicant had intended. Mr Ryan stated that the dose should be that effective for the removal of roundworms. Since this differs from the plain meaning of the term as used in the claim, it follows that there is a section 40 deficiency in the claim which must be rectified. For the purpose of my decision I will adopt the meaning that Mr Ryan has specified, with the expectation that the claim will be amended to bring it into line with the intended meaning (I note that the specification appears to in substance disclose a dose effective for the removal of roundworms).
(iv) Together with
The claim specifies that the praziquantel is administered “together with” the avermectin or milbemycin. The plain meaning of “together with” is that the two agents are administered at the same time, and not at widely separated times. This is consistent with the description, which clearly is directed to the co-administration of the two active agents in a single dosage unit. I believe that the plain meaning should be adopted.
(v) Derivatives thereof
No issue was raised by the parties in relation to this term. I consider that the term is used so as to include simple chemical derivatives of avermectins and milbemycins that do not alter the basic activity of the substance.
(vi) Synergy
The claim makes no reference to the need for the composition to operate in a synergistic manner. The claim defines the use of a specific composition, and the assertion of the specification is that synergy is an inherent result of using such a composition.
DECISION
In making my decision I am aided by evidence from a large number of declarants. The declarants have a range of backgrounds and qualifications. It was argued that some of the declarants are not in a position to give evidence of the common general knowledge in Australia, or to opine on what would have been obvious to them. The present invention lies in an area where the sciences of chemistry and biology overlap, and people from a range of backgrounds could have evidence that is relevant to this opposition. The sensible approach is to have regard to all of the evidence, and if there is a conflict in the evidence or surprising evidence that is not corroborated by other declarants, then have regard to the background of the declarants in order to assess the weight to be given to the evidence. However, the evidence of the declarants is quite consistent on most of the points that are essential for my decision. There are some areas of disagreement, but these seem to be differences of emphasis. Areas where the declarants strongly disagree turn out to be matters that are not central to my decision. I will refer to the evidence of the declarants where appropriate, but since many of the declarants make similar statements, I will generally only refer to the evidence of one declarant in order to avoid repetition. However, it should be understood that generally all opinions appear in several declarations.
1. The state of the art and the commercial situation
The declarants referred to the general landscape in which the present application sits. In order to better understand what follows I will briefly describe that landscape. It is well known that horses easily become infected with worms (both roundworms and tapeworms) as well as other parasites. A. perfoliata is the most common tapeworm in horses (page 2 of the provisional application; Duncan declaration, paragraph 9), and its occurrence in horses has been well known since 1782 (Boray declaration in answer to the Merial opposition, paragraph 5). Mild infection with tapeworms does not lead to obvious clinical symptoms, but heavy and persistent infestation has been associated with more serious syndromes (Duncan declaration in reply to the AHPC opposition, paragraph 9). The treatment of horses requires large dosages of anthelmintic agents due to the large body mass of horses. Consequently the cost of the active agents is a commercial consideration.
It appears that the use of active agents in veterinary compositions is influenced by whether or not the agents are covered by existing patents. For instance, Dr Wang stated that “animal health products are particularly driven by the economics of the particular actives, and the legal availability of actives covered by patents” (Wang declaration in reply to the AHPC opposition, paragraph 40).
Avermectins and milbemycins have been known since the 1970s (the milbemycins were first described in 1974 and the avermectins were first described in 1979). It was known that they are useful for the treatment of roundworms, but they are not useful for the treatment of tapeworms (page 1A of the specification). One of the first disclosures of the use of avermectins was in Australian patent number 513641 (application number 24220/77), which specifically discloses a class of substances designated as C-076 (which are now known as avermectins). AU 513641 ceased on 13 April 1994.
Praziquantel was disclosed in Australian patent number 485552 (and its family members) filed in 1974 in the name of Merck (known as the Bayer patent). It was known that praziquantel is useful for the treatment of tapeworms (for instance, Arundel declaration in support of the AHPC opposition, paragraph 10). AU 485552 ceased on 16 December 1994, following an extension of term of the patent. The extension of term was specifically in relation to the substance praziquantel.
2. Priority date
The opponents argued that the application is not entitled to claim priority from the provisional application, and thus takes the date of filing as its priority date. As a consequence, three documents published between the date of the filing of the provisional application and the date of filing of the complete application would be citations for the purposes of novelty. I will deal briefly with this allegation.
It was asserted that there is a substantial difference between the invention disclosed in the provisional specification and that in the complete. The differences identified by the opponents are:
a)        the claimed dosage rate is not disclosed;
b)        the effective dosage is only disclosed as 0.2 mg/kg;
c)        the administration “together with” is only disclosed as co-administration; and
d)        there is no disclosure of the use of milbemycins.
A claim of a complete application is entitled to priority from a provisional application if it is fairly based on the provisional specification (regulation 3.12). The provisional specification is titled “Equine anthelmintic formulations”. The provisional specification introduces the invention on page 2 as follows:
“The present invention relates to a formulation for the control of parasitic infestations in Equidae and in particular to a formulation for simultaneous treatment of roundworms and tapeworms.”
At page 3 the invention is describes in general terms as follows:
“According to the present invention there is provided an anthelmintic composition for equine use comprising Praziquantel in combination with a second active chosen from a group comprising Avermectins and Milbemycins.
Trials have indicated that Praziquantel in combination with an Avermectin and/or a Milbemycin may be administered without any diminution of the efficacy of either drug due to the administration in combination. Furthermore a synergistic effect has been observed to the extent that when in combination with Avermectins or Milbemycins the required dose rate for Praziquantel in equine animals is between 0.1 and 4.0 mg/kg. It has however been observed that Praziquantel may be administered to equine animals in higher dosage rates without adverse effects and in this regard dosage rates of up to 7.5 mg/kg of body weight have been trialled.”
There are three compositions exemplified (abamectin-praziquantel paste, ivermectin-praziquantel drench, and abamectin-praziquantel tablets). A trial of the compositions in horses is reported. In all cases the avermectin is used at a dosage of 0.2 mg/kg and the praziquantel is used at a dosage of 1 mg/kg. It is clear that a dosage rate of praziquantel of 0.5 to 2 mg/kg is not specifically disclosed. Rather a dosage rate of 0.1 to 4.0 mg/kg is suggested, and a dosage of 1 mg/kg is exemplified. It seems that a smaller and more specific range is now claimed. The broad dosage rate range is said to be synergistic, so there is no change in the nature of the invention associated with the narrowing of the range. The dosage rate of the avermectin or milbemycin appears to be the amount that would normally be administered, “without any diminution of the efficacy” of the agent. Consequently the dosage rate of the avermectin or milbemycin used in the provisional specification is effective against roundworms, which is the same as that in the complete specification. It is clear that the provisional specification discloses a co-administration of the two anthelmintic agents. Since the claims of the complete specification are limited to substantially co-administration, there is no departure from the thrust of the provisional specification. The provisional specification does not exemplify the use of a milbemycin, but it is clearly disclosed that a milbemycin can be used in place of the avermectin. Consequently there is a basis for claiming milbemycins.
I conclude that the invention claimed is fairly based on the provisional application, and is thus entitled to the priority date of 28 November 1994. I will not consider the three alleged citations.
3. Novelty
It was argued by both opponents that the invention lacks novelty in the light of Australian patent application 80711/82 (referred to as the Sankyo patent). It is well established that the general test for anticipation is the reverse infringement test. The classic formulation of this test is that given by Aickin J in Meyers Taylor Pty Ltd v Vicarr Industries Ltd (1977) 137 CLR 228, at page 235:
“The basic test for anticipation or want of novelty is the same as that for infringement and generally one can properly ask oneself whether the alleged anticipation would, if the patent were valid, constitute an infringement”
This test is satisfied if the alleged anticipation discloses all the essential features of the invention as claimed (see Nicaro Holdings Pty Ltd v Martin Engineering Co (1990) 91 ALR 513 at page 517; 16 IPR 545 at page 549). A citation is part of the prior art base for the purposes of novelty if it was published before the priority date of the claim (see definition of "prior art base" in Schedule 1 of the Act).
(i) Essential features
It was stated by the opponents that all of the features of claim 1 are essential features. I agree, although some of the features must be construed in a specific manner (as discussed previously). The essential features of claim 1 are:
* a method of treating parasites, consisting of the steps of
* orally administering
* to equine animals infected by, or likely to be infected by, worms
* a composition comprising
- a dose of 0.5 to 2.0 mg of praziquantel per kilogram of animal body weight
- together with
- a dose of an avermectin or milbemycin (or a derivative) sufficient to kill roundworms (albeit complete efficacy is not required)
I note that the treatment does not have to result in complete efficacy. Additionally, it is important to note that synergy is not an essential feature of the invention. To the extent that synergy exists, it is an inherent feature.
(ii) The disclosure of the Sankyo patent
Australian patent application number 80711/82, which was sealed as patent number 552403 (the Sankyo patent) was lodged in Australia on 23 February 1982 and was published on 2 September 1982. The Sankyo patent discloses an anthelmintic composition comprising a mixture of a milbemycin (called B-41) or an avermectin (called C-076), and another known anthelmintic agent (page 1A). The known anthelmintic can be praziquantel (page 13). Sankyo notes that there is a surprising synergy between the avermectin or milbemycin and the known anthelmintic agent, which enables a reduced dose of anthelmintic to be used (page 13). The Sankyo composition is useful for the treatment of a range of animals, including horses (page 17), against a range of parasites, including both roundworms and tapeworms (pages 17 to 19). The Sankyo composition can be administered orally (page 19).
The Sankyo patent differs from the present claims in that it does not specifically disclose the particular dosage rate used in the present application. Sankyo describes the dosage rate in general terms as follows (page 21):
“The optimum amount of the active ingredients of the composition of the invention desired to achieve best results will vary depending upon the kind of animal to be treated, the type of parasitic infection and the degree of infection. However, in general, we have found that good results are achieved by using, for oral administration, from 0.01 to 100 mg, preferably from 0.1 to 50 mg, of the B-41, C-076 or 22,23-dihydro C-076 series antibiotics and from 0.5 to 200 mg, preferably from 1 to 30 mg, of the benzimidazole, salicylamide or isoquinoline compound, per kg body weight.”
[Note: praziquantel is an isoquinoline compound]
A composition containing praziquantel and the milbemycin B-41 is prepared in Example 3 of Sankyo, and the results of the use of the composition in dogs infected with Trichuris vulpis (a species of roundworm) and Dipylidium caninum (the commonest species of dog tapeworm) are reported in Table 6. The composition is administered as a gelatin capsule. I consider that is most likely to be an oral administration. Two relevant compositions are reported:

Praziquantel (mg/kg) Milbemycin B-41D (mg/kg) Efficacy against
T. vulpis Efficacy against
D. caninum

2.5 0.05 100 100

5 0.05 100 100
Thus Sankyo exemplifies the oral administration of a composition containing 2.5 mg/kg of praziquantel in combination with a milbemycin. The specification suggests that any amount between 0.5 and 200 mg/kg can be used, and preferably between 1 and 30 mg/kg.
(iii) Is the invention novel in the light of the Sankyo patent?

It is clear that Sankyo explicitly discloses the use of a composition containing 2.5 mg/kg of praziquantel, and suggests that other amounts could be used. The amount of milbemycin used is 0.05 mg/kg, which is effective against roundworms in dogs. The evidence suggests that this dosage of milbemycin would not be effective in horses (the Boray declaration in answer to the Merial opposition, paragraph 6(e), states that 0.2 mg/kg is the effective dose). Thus there is not an explicit disclosure of the dosage of praziquantel and milbemycin as claimed in the present application. Would those matters that are generically suggested by the Sankyo patent, but are not explicitly disclosed, be regarded as sufficiently disclosed to render the claimed invention lacking in novelty? The Sankyo patent encompasses literally billions of possible compositions, and it is not reasonable to suggest that every one of these compositions is clearly and unmistakably disclosed. It is only those things that the instructed reader would consider as having been made public that are clearly and unmistakably disclosed. The examples are certainly made public, and the preferred forms are probably made public, but forms of the invention of which the specification provides no explicit mention are probably not made public (see Pharmacia Aktiebolag v Ueno Fine Chemicals Industry Ltd (1995) 34 IPR 445) in the absence of evidence to the contrary.
There is nothing that suggests that compositions as claimed in the present application are made public. The general range disclosed in the Sankyo patent does not prejudice the novelty of the specific range claimed in the present application. These variations are properly considered under the heading of inventive step, and not as a part of novelty.
4. Inventive step
It was argued that the invention is obvious in the light of the common general knowledge, or in the light of Australian patent application 80711/82 (referred to as the Sankyo patent), an article in the Journal of the Helminthological Society (referred to as the Lyons article) and Australian patent number 485552 (referred to as the Bayer patent) each considered separately with the common general knowledge.
Section 7(2) provides a definition of inventive step for the purposes of the Patents Act.
“(2) For the purposes of this Act, an invention is to be taken to involve an inventive step when compared with the prior art base unless the invention would have been obvious to a person skilled in the relevant art in the light of the common general knowledge as it existed in the patent area before the priority date of the relevant claim, whether that knowledge is considered separately or together with either of the kinds of information mentioned in subsection (3), each of which must be considered separately.
(3) For the purposes of subsection (2), the kinds of information are:
(a)prior art information made publicly available in a single document or through doing a single act; and
(b)prior art information made publicly available in 2 or more related documents, or through doing 2 or more related acts, if the relationship between the documents or acts is such that a person skilled in the relevant art in the patent area would treat them as a single source of that information;
being information that the skilled person mentioned in subsection (2) could, before the priority date of the relevant claim, be reasonably expected to have ascertained, understood and regarded as relevant to work in the relevant art in the patent area.”
[The prior art base is defined in Schedule 1 of the Act.]
It is clear that inventive step is a matter that is presumed, unless it is demonstrated that the invention is obvious. The assessment of obviousness can be made against the common general knowledge alone, or the common general knowledge together with a document (or act) of the type covered by section 7(3). Section 7(3) documents must satisfy several requirements: the document must be publicly available inside or outside Australia (see the definition of "prior art base"); and the document would have been reasonably expected to have been ascertained, understood and regarded as relevant.
The normal approach to obviousness is the problem-solution approach: for instance, see Rhone-Poulenc Rorer S.A.'s Application [1995] APO 50. I note in passing that the problem-solution concept is evident in judicial decisions such as Minnesota Mining and Manufacturing Co v Beiersdorf (Australia) Ltd (1980) 144 CLR 253 (e.g. at 298: "this solution to the known problem") and Winner v Ammar Holdings Pty Ltd (1993) 113 ALR 63 (e.g. at 67: "The problem and the solution were readily apparent"). Once the problem has been formulated, and the common general knowledge and the prior art base has been determined, the question of whether the claimed solution is obvious must be addressed. The test for obviousness is whether it would have been a matter of routine to proceed to the claimed invention.
“It is still correct to say that a valid patent may be obtained for something stumbled upon by accident, remembered from a dream or imported from abroad, if it otherwise satisfies the requirements of the legislation. What is important is that the patent itself should involve an inventive step, whether or not it was consciously taken by the patentee and whether or not it appeared obvious to the patentee himself. The test is whether the hypothetical addressee faced with the same problem would have taken as a matter of routine whatever steps might have led from the prior art to the invention, whether they be the steps of the inventor or not.”
[Wellcome Foundation Ltd v V.R. Laboratories (Aust.) Pty Ltd (1981) 148 CLR 262 286]

The question of what would be routine can be considered using the "obvious to try" approach. This approach is well explained in Beecham Group Ltd's (Amoxycillin) Application [1980] RPC 261 (which has been approved in Coopers Animal Health Australia Ltd v Western Stock Distributors Ltd (1986) 67 ALR 390 at 410 and W R Grace & Co v Asahi Kasei Kogyo Kabushiki Kaisha (1993) 25 IPR 481 at 492 - 494) at 290 - 291:
“It is clearly established that, for a particular step or process to be obvious for the purpose of either section, it is not necessary to establish that its success is clearly predictable. It will suffice if it is shown that it would appear to anyone skilled in the art but lacking in inventive capacity that to try the step or process would be worthwhile. Worthwhile to what end? It must, in my opinion, be shown to be worth trying in order to solve some recognised problem or meet some recognised need.”
[citations omitted]
In the present case a key question is whether an invention is obvious if it would have been considered obvious to try as a technical solution to the problem, but would not have been adopted in practice because it would amount to an infringement of an existing patent. If the infringement of an existing patent were a relevant consideration, then the obviousness of an invention would depend on whether a person skilled in the art (being the person who assesses obviousness) owns the patent in question. This is clearly a question to which there is no sensible answer. Instead the obviousness question should focus solely on technical issues. This emphasis seems to be evident in views expressed by judges:
“However, the test of whether something was 'worth trying' involves questions of degree … If the expectation of success is sufficiently predictable, and the effort involved is not going to be very great, it may well be that there is no inventive step. On the other hand, if the expectation of ultimate success is doubtful and the effort involved is great, the person undertaking the work should be entitled to a monopoly. A patent monopoly is awarded, not to reward genius but to encourage the disclosure of information which is of value to the public in that it takes the store of knowledge ahead by the requisite 'inventive step'.”
[ICI Chemicals & Polymers Ltd v Lubrizol Corp Inc (1999) 45 IPR 577 at 600-601, citations omitted]
(i) The problem
The identification of the problem is the key step in the problem-solution approach to inventive step. If the problem is wrongly identified, then the rest of the inventive step analysis is inevitably wrong. The present application is a case where this is particularly relevant. In University of Georgia Research Foundation, Inc v BioChem Pharma, Inc (2000) 51 IPR 222 at 247, (2001) AIPC 91-676 at 39,227 I suggested that the problem can generally be read out of the specification. For example, the explanation of the prior art and the stated problems that existed provide a reasonable starting point for the problem. However, I noted that sometimes it may be necessary to look beyond the specification to the general state of the art, and what the declarants state were recognised problems in the art. That approach seems equally relevant in the present case. It is relevant to the present case to note that the problem does not have to incorporate every advantage possessed by the invention as claimed. In appropriate circumstances, an advantage possessed by an invention may be characterised as a bonus (see Hallen Co v Brabantia (UK) Ltd [1991] RPC 195).
The structure of the specification (as discussed previously) starts with the proposition that the problem is to identify a composition that is active against both roundworms and tapeworms. The composition gives a “surprising” increase in anthelmintic spectrum. The composition is stated to further display a synergistic effect in relation to A. perfoliata. It is apparent from the face of the specification that the invention resides in simultaneously treating roundworms and tapeworms, and that an enhanced activity against A. perfoliata is a bonus (as distinct from a part of the problem).
Mr Ryan’s written submissions in relation to the AHPC opposition handed up at the hearing put the problem in a very different way:
“The proper problem that has to be considered as having an obvious solution is the effective treatment of A. perfoliata in equides using a synergistic combination that would achieve efficacies that would not be achieved by the use of Praziquantel alone.” (paragraph 181)
Mr Ryan’s oral submissions reiterated this, and invited me to see the problem as lying in an improved activity against A. perfoliata, and the broader anthelmintic spectrum as a bonus. This formulation of the problem can be seen as solved by the invention as claimed, and to this extent it is based on the specification. Mr Beuvry identified the problem in a way that neatly incorporated the broad spectrum and synergistic elements:
“the problem solved by the Invention was to provide a therapeutic composition allowing treatment of equine animals having or suspected of contracting:
. either an isolated infection by Anoplocephala perfoliata,
. or a co-infection induced by Anoplocephala perfoliata together with other tapeworms or roundworms”
[Beuvry declaration in answer to the AHPC opposition, paragraph 69; Beuvry declaration in answer to the Merial opposition, paragraph 75]
The difficulty with the formulations of the problem presented by Virbac is that they are based on a desire to limit the amount of praziquantel that is used in the treatment of horses. The evidence suggests that praziquantel was not routinely used to treat horses, but was normally used for small animals (for instance, see the Martin declaration in answer to the AHPC opposition, paragraph 26 and the Martin declaration in answer to the Merial opposition, paragraph 25). Consequently it is unlikely that there would have been a recognised problem in the use of praziquantel to treat horses. The clearest report of the use of praziquantel to treat horses was the Lyons article, which suggested a dosage rate of 0.75 or 1.0 mg/kg. If this was seen as a high dosage, then the present application would not have solved the problem (as it claims even higher dosages of praziquantel). The evidence suggests that there was no recognised problem in the art relating to the dosage of praziquantel used to treat horses.
I conclude that the problem determined from a reading of the specification is the problem that I should use to determine whether there is an inventive step. Given that the claims are drafted as methods of treatment, the problem is properly framed as:
to identify a method of treating equine animals against infection by both roundworms and tapeworms
(ii) The person skilled in the art
The problem lies in the field of veterinary science. This necessarily involves the arts of chemistry, biology, biochemistry, and probably some related arts. The person skilled in the art is likely to be a team of people having skills in these arts.
(iii) Common general knowledge
It is well established that common general knowledge is “the background knowledge and experience which is available to all in that field in considering the making of new products or making of improvements in old products” (ICI Chemicals and Polymers Ltd v Lubrizol Corporation Inc (1999) 45 IPR 577 at 599, [111]). The common general knowledge is not restricted to matters that the skilled worker would carry around in their head, but extends to information that is habitually consulted by the skilled worker in the field:
“That is not to say that the whole of the content of ‘common general knowledge’ need be within the conscious awareness of the hypothetical non-inventive skilled worker. For example, there may be publications of technical and detailed information that are habitually consulted by the hypothetical skilled worker. Notwithstanding that the hypothetical skilled worker would not have the whole of the contents of such reference material in his or her mind, such information should be regarded as part of common general knowledge.”
Aktiebolaget Hässle v Alphapharm Pty Ltd (2000) 51 IPR 375 at 391, [73]
The opponents relied on Bristol-Myers Squibb Co v F.H. Faulding & Co Ltd (2000) 97 FCR 524, 46 IPR 553 at 564, [30], to argue that the admitted prior art in the specification is part of the common general knowledge. I understand this decision to state that if the specification asserts a matter is common general knowledge, then the Commissioner can accept that assertion without independent verification. The present application refers to two prior art documents as follows (page 2 of the specification):
“Praziquantel combined with another anthelmintic has already been claimed in the Patent GB 2252730 by Ancare Distributors Limited but these associations are not synergistic and only increase the anthelmintic spectrum in sheep.”
“Kitano in the Patent EP 59074 claims associations of macrolide anthelmintic agents and a variety of several anthelmintic agents like benzimidazole, salicylamide and isoquinoline compounds with enhanced anthelmintic activity.”
I do not consider that the specification is asserting that either of these documents is part of the common general knowledge. Instead I will look to the evidence of the declarants to establish what information is part of the common general knowledge.
The parties are generally in agreement that the following matters are common general knowledge.
(i)        Infection by worms
Mammals often become infected with parasitic worms (for example, see the first Wang declaration in support of the AHPC opposition, paragraph 22, and the Rolfe declaration in support of the Merial opposition, paragraph 21). Infection often involves more than one worm type (see the first Wang declaration in support of the AHPC opposition, paragraph 22). However, tapeworms were not thought to be a major problem in horses until the late 1980s or early 1990s because the clinical symptoms due to them were minor, and were masked by the effects of the more pathogenic strongyles. It was not until the strongyles were controlled that tapeworms were seen to have an effect on the health of the horse (Arundel declaration in reply to the AHPC opposition, paragraph 12, 52).
(ii)       A. perfoliata infection
A. perfoliata was a known tapeworm in horses (Rolfe declaration in support of the Merial opposition, paragraph 21).
(iii)      Praziquantel
Praziquantel is highly effective against tapeworms (Arundel declaration in support of the AHPC opposition, paragraph 10; Rolfe declaration in support of the Merial opposition, paragraph 25), but not against roundworms (first Wang declaration in support of the AHPC opposition, paragraph 22). Praziquantel was generally considered to be an agent for use in small animals (see the Martin declaration in answer to the AHPC opposition, paragraph 26 and the Martin declaration in answer to the Merial opposition, paragraph 25).
(iv)      Avermectins and milbemycins
Avermectins and milbemycins are effective against roundworms (Jenkins declaration in answer to the AHPC opposition, paragraph 58; Rolfe declaration in support of the Merial opposition, paragraph 23)
(v)       Formulation
Differences in the way that a composition is formulated influence the efficacy achieved (first Wang declaration in support of the AHPC opposition, paragraph 40).
(iv)      Matters of routine
There are other matters that I have characterised as matters of routine. These matters could be characterised as common general knowledge, but they are things that a person would do, rather than things they would know (the distinction is semantic rather than substantial). I will go through the significant matters in turn.
(i)        Dosage optimisation
I accept that it is routine to optimise the dosage of an active agent (Wang declaration in reply to the AHPC opposition, paragraph 7; Rolfe declaration in reply to the Merial opposition, paragraph 88).
(ii)       Combination therapy
Combination therapy is the normal way to treat two different worm types (Arundel declaration in support of the AHPC opposition, paragraphs 9, 18; Jenkins declaration in answer to the Merial opposition, paragraph 59). I note that it has been accepted that this was also routine in New Zealand by 1991 (see Ancare New Zealand Ltd v Novartis New Zealand and Cyanamid of NZ Ltd [2000] NZCA 127). The combination of praziquantel with avermectins or milbemycins is known (see the first Wang declaration in support of the AHPC opposition, paragraphs 27-32), but the evidence suggests that this was public knowledge rather than common general knowledge.
(iii)      Patent literature
It is routine for workers in the art to read patents (Beveridge declaration in support of the AHPC opposition, paragraph 4).
(iv)      Non-patent literature
It is routine for workers in the art to read technical literature and conduct literature searches (Beveridge declaration in support of the AHPC opposition, paragraph 4; Rolfe declaration in support of the Merial opposition, paragraph 20).
(vi)      Praziquantel dosage
The use of 1 mg/kg of praziquantel to treat A. perfoliata was known (see the Larson document, which is Exhibit MJC-2, and is translated as Exhibit MJC-51, of the Caine declarations; also see the Lyons article). However, there is no compelling evidence that this information was common general knowledge.
(vii)     Pastes
The evidence suggests that it is routine to prepare paste formulations (Arundel declaration in support of the AHPC opposition, paragraph 13; Rolfe declaration in support of the Merial opposition, paragraph 30).
(viii)     Species extrapolation
The evidence is conflicting on whether it is possible to extrapolate results obtained in one situation to another situation. For instance, on the question of whether it is possible to extrapolate results obtained in one species of animal to a different species of animal (which I will call species extrapolation), one group of declarants state that there would be an expectation of success in similar animals (Wang declaration in reply to the AHPC opposition, paragraph 7, 8), and another group of declarants declare that it is not possible to be sure of success in a different species (Jenkins declaration in answer to the AHPC opposition, paragraph 14). Evidence was given of an example where an agent was effective against one type of tapeworm, but not against another (pyrantel embonate is effective against A. perfoliata but not against A. mamillana; see the Beuvry declaration in answer to the AHPC opposition, paragraph 44 and the Beuvry declaration in answer to the Merial opposition, paragraph 31). Other evidence indicates that this an exception (Wang declaration in reply to the AHPC opposition, paragraph 45). A careful reading of the declarations suggests to me that the success of an agent in treating worms in one species of animal leads to an expectation of success in similar species. However, success is not certain, and dosages cannot be confidently extrapolated between species (as noted in the Arundel declaration in support of the AHPC opposition, paragraph 6). I believe that the opinion of Dr Wang accurately reflects the situation:
“it is to be emphasised that activity in one species is indicative of activity in another mammal, albeit that doses may vary due to differences in pharmacokinetics, metabolic rate, and the body size between the animal species”
[Wang declaration in reply to the AHPC opposition, paragraph 41]
(ix)      Geographical extrapolation
The evidence is also conflicting on whether it is reasonable to extrapolate results obtained in one country to another country (which I will call geographical extrapolation). A number of declarants for Virbac forcefully declared that geographical extrapolation of results from overseas tests is not legitimate (for example, Martin declaration in answer to the AHPC opposition, paragraph 13; Martin declaration in answer to the Merial opposition, paragraph 12). Declarants for the opponents stated that it is proper to extrapolate overseas results (Rolfe declaration in reply to the Merial opposition, paragraph 29). The declarants all have appropriate Australian experience to give this evidence. From a careful reading of the evidence I have come to the view that while results can be repeated in some cases and not in others, the real question is whether the likelihood of repeatability is such that geographical extrapolation should be presumed to be the norm or an exception. It is significant to note that Virbac have filed patent applications equivalent to the present application in a number of countries, and have obtained patents in some of those countries (the text of these applications refer to the tests done in Australia). If Virbac believed that geographical extrapolation was the exception and not the norm, they would not have applied for patents outside Australia without reconfirming the work in each country and inserting that information into the specifications. The actions of Virbac satisfy me that geographical extrapolation should be accepted as the norm, but with the caveat that success is not certain.
I note that Dr Slocombe declares (Slocombe declaration in reply to the AHPC opposition, paragraph 29) that the results of later experiments in different parts of the world gave similar results against A. perfoliata. This is consistent with my conclusion.
(x)       The use of praziquantel
The evidence is that praziquantel and its anthelmintic properties was a part of the common general knowledge. As noted in my discussion of the law, it is not relevant that praziquantel was still the subject of patent protection in Australia (the praziquantel patent ceased in Australia on 16 December 1994, which is after the priority date of the present application). It seems clear that praziquantel was understood to be a useful anthelmintic and would have been a routine choice. Consistent with this conclusion, interest in praziquantel increased following the expiry of the patent protection (Rolfe declaration in reply to the Merial opposition, paragraph 6).
(xi)      The use of avermectins or milbemycins
The evidence is that avermectins and milbemycins and their anthelmintic properties were part of the common general knowledge, and their use would have been routine. As noted in my discussion of the law, it is not relevant whether milbemycins and avermectins are or were the subject of patent protection in Australia. It appears that abamectin, ivermectin and moxidectin are merely routine members of the class of avermectins and milbemycins.
(v)       Routine documents
The opponents relied on the decision of the Federal Court in Aktiebolaget Hässle v Alphapharm Pty Ltd (2000) 51 IPR 375 to argue that it was possible to have regard to some of the documents in evidence. The Court stated that it is permissible to rely on information that is not part of the common general knowledge if it would have been found as a routine step in understanding the problem:
“Another area where it may be permissible to rely upon information that is not part of the common general knowledge is where the hypothetical addressee, faced with a problem, would resort to information that is fundamental to understanding the nature of the problem, if this were found to be a routine step that would have led from the prior art to the invention: cf Wellcome Foundation at CLR 286 per Aickin J. Such information would include information about the basic characteristics of a drug for which a formulation is to be found.”
Aktiebolaget Hässle v Alphapharm Pty Ltd (2000) 51 IPR 375 at 391, [74]
The Court took a narrow view of what information was relevant on this basis - it includes essential background information, but not general information. Given the nature of the problem, this would be information on the roundworms and tapeworms of horses. I would not expect it to include information dealing with the known treatments of horses. The documents that the opponents rely upon are better considered under section 7(3).
(vi) Is the invention obvious in the light of common general knowledge alone?

As is normal in patent oppositions, the declarants for the opposing sides hold starkly different views on the obviousness of the invention. The best approach is to start with the problem and examine the relevant evidence.
In order to establish that the invention lacks an inventive step, four things must demonstrated:
a) it would have been routine to select two agents that are individually active against tapeworms and roundworms and combine them into a single composition,
b) it would have been routine to select praziquantel from the range of available agents for the treatment of tapeworms,
c) it would have been routine to select an avermectin or milbemycin from the range of available agents for the treatment of roundworms, and
d) it would have been routine to adjust the amount of the active agents to achieve the dose that is claimed.
It seems clear that it would have been routine to combine two agents that are individually active against tapeworms and roundworms. This is made explicitly clear in the declaration of Arundel in support of the AHPC opposition, paragraph 15:
“it would have been the obvious approach for anyone working in the field to combine the most effective chemicals against cestodes with the most effective against nematodes to remove tapeworms, nematodes and bots at a single treatment”
It is established that it was common general knowledge that praziquantel was an effective treatment for tapeworms, and that avermectins and milbemycins were effective treatments for roundworms. I conclude that it would have been obvious to try praziquantel and an avermectin or milbemycin. Dosage optimisation was routine, so it is routine to arrive at a dosage within the scope of claim 1.
Addressing the dependent claims now, the evidence shows that the compounds named in claims 2 to 5 were routine, so they lack an inventive step. The specific quantity specified in claims 6 and 7 appears to be merely the optimised quantity, which is routine. Claims 6 and 7 also lack an inventive step. Finally, the production of a paste is routine, so claim 8 also lacks an inventive step.
(vii) Is the invention obvious in the light of the citations?
The Lyons article
The Lyons article is “Activity of Praziquantel Against Anoplocephala perfoliata (Cestoda) in Horses” J. Helminthol. Soc. Wash. 59(1), 1992, pp 1-4 by E.T. Lyons, S.C. Tolliver, H. Drudge, D.E. Granstrom and S. Stamper. I can find no declarations establishing the date of publication of the Lyons article. The copy of the Lyons article served by Merial bears a date stamp of Badham Library, at the University of Sydney. The date is clearly 4 March 1992. It seems clear from the face of the copy of the Lyons article served as evidence by Merial that Lyons was published by at least 4 March 1992. Bearing in mind that the problem is to identify a method of treating equine animals against infection by both roundworms and tapeworms, this article is clearly relevant to work in the art (as it is apparent from the title that it relates to the treatment of the tapeworm A. perfoliata in horses). The document is of a type that the evidence suggests is routinely considered by workers in the art, so I consider it would have been ascertained. The document would have been understood, as it is a straight forward article.
Lyons reports a study of the efficacy of praziquantel alone as a treatment of A. perfoliata in horses. The work was carried out by workers from the University of Kentucky using 35 cull animals. Only 19 of the animals were found to be infected with A. perfoliata. The results of the study are reported as:

Dosage rate of praziquantel (mg/kg) Route of administration Number of horses tested Percentage removal of
A. perfoliata Percentage of horses having ≥ 90% removal of A. perfoliata

0.75 IO 11 82 - 100 91

1.0 IO 2 100 - 100 100

1.0 ST 6 89 - 100 83
Note: IO = intraorally; ST = stomach tube
Given the view I have taken of the efficacy requirement in the claims of the present application, the removal of 80% of the A. perfoliata that is achieved in all cases in the Lyons article would be regarded as effective. Clearly the number of horses tested make the Lyons article far from definitive (a fact acknowledged in the article). However, the Lyons article clearly is stating that both 0.75 and 1.0 mg/kg of praziquantel are effective in the oral treatment of horses infected with A. perfoliata.

There is evidence that the results in the Lyons article were reproduced in later work. I do not believe that information published after the priority date of the present application is relevant to the question of whether the present application has an inventive step in the light of the Lyons article.
In order to establish that the invention lacks an inventive step in the light of the Lyons article, four things must be demonstrated:
a) it would have been routine to extrapolate the results to Australia,
b) it would have been routine to select two agents that are individually active against tapeworms and roundworms and combine them into a single composition,
c) it would have been routine to select an avermectin or milbemycin from the range of available agents for the treatment of roundworms, and
d) it would have been routine to adjust the amount of the active agents to achieve a dose that is effective against both types of parasites.
I have already found that geographical extrapolation is reasonable, so it would be reasonable to extrapolate the Lyons result to Australia. I have also determined that it was routine to combine two actives into a single treatment. Turning to the third question, the evidence is clear that the use of avermectins and milbemycins would have been a matter of routine. The final question of the dose of each agent is fairly straight forward - the evidence establishes that it would have been routine to determine the optimal dose. Additionally, Lyons suggests the use of 0.75 or 1.0 mg/kg of praziquantel, which falls in the centre of the claimed range, so no adjustment is necessary. The amount of avermectin or milbemycin that would be used would be whatever was necessary to be effective against roundworms. Thus claim 1 is lacking in inventive step. I consider that the entire dosage range of praziquantel would be a matter of routine, as the range is based solely on efficacy of the composition.
Addressing the dependent claims now, the evidence shows that the compounds named in claims 2 to 5 were routine, so they lack an inventive step. The specific quantity specified in claims 6 and 7 appears to be merely the optimised quantity, which is routine. Claims 6 and 7 also lack an inventive step. Finally, the production of a paste is routine, so claim 8 also lacks an inventive step.
The Bayer patent
Australian patent number 485552 (the Bayer patent) was lodged in Australia on 16 December 1974, and was published on 17 June 1976. Bearing in mind that the problem is to identify a method of treating equine animals against infection by both roundworms and tapeworms, this patent is clearly relevant (as it relates to the treatment of parasitic worms in mammals such as horses). The document is of a type that the evidence suggests is routinely considered by workers in the art, so I consider it would have been ascertained. The document would have been understood, as it is a straight forward patent.
The Bayer patent discloses a new group of isoquinoline compounds. The generic disclosure includes praziquantel (when the R group is cyclohexyl), and the compound corresponding to praziquantel is prepared (see example 10). Praziquantel is tested against roundworms in both mice and dogs (pages 39 to 44). It is specifically mentioned that the compounds of the Bayer patent may be used against Anoplocephala in horses (page 35). The amount of active agent used is “0.01 to 250 and preferably of about 0.5 to 100 mg/kg, orally or subcutaneously” (page 38). Bayer notes that a broader spectrum of activity can be achieved by mixing the isoquinoline compound with another active material (page 39). Pages 88 to 92 exemplify compositions containing praziquantel. It is clear that the Bayer patent discloses praziquantel, and that it is an effective agent against roundworms. The examples refer specifically to use of the compositions in humans (examples 53, 55, 56, 57, 58) and cattle (example 60).
In order to establish that the invention lacks an inventive step in the light of the Bayer patent, five things must be demonstrated:
a) it would have been routine to extrapolate the result to horses,
b) it would have been routine to extrapolate the result to Australia,
c) it would have been routine to select two agents that are individually active against tapeworms and roundworms and combine them into a single composition,
d) it would have been routine to select an avermectin or milbemycin from the range of available agents for the treatment of roundworms, and
e) it would have been routine to adjust the amount of the active agents to achieve a dose that is effective against both types of parasites.
I have already concluded that species extrapolation is reasonable. This is reinforced by the fact that the specification suggests the compounds will be useful in horses. It is unclear where the tests in the Bayer patent were carried out, but the fact that it is an Australian patent makes it reasonable to extrapolate the results to Australia. I have already determined that it was routine to combine two actives into a single treatment. Turning to the fourth question, the evidence is clear that the use of avermectins and milbemycins would have been a matter of routine. The final question of the dose of each agent is fairly straight forward. It would have been routine to determine the optimal dose. Additionally, Bayer suggests the use of 0.5 to 100 mg/kg of praziquantel. The claimed range falls entirely within this range, so clearly the starting point for routine optimisation has already been disclosed. Thus claim 1 lacks an inventive step. I consider that the entire dosage range of praziquantel would be a matter of routine, as the range is based solely on efficacy of the composition.
Addressing the dependent claims now, the evidence shows that the compounds named in claims 2 to 5 were routine, so they lack an inventive step. The specific quantity specified in claims 6 and 7 appears to be merely the optimised quantity, which is routine. Claims 6 and 7 also lack an inventive step. Finally, the production of a paste is routine, so claim 8 also lacks an inventive step.
The Sankyo patent
Australian patent application number 80711/82, which was sealed as patent number 552403 (the Sankyo patent) was lodged in Australia on 23 February 1982 and was published on 2 September 1982. Bearing in mind that the problem is to identify a method of treating equine animals against infection by both roundworms and tapeworms, this patent is clearly relevant (as it relates to the treatment of parasitic worms in mammals such as horses). The document is of a type that the evidence suggests is routinely considered by workers in the art, so I consider it would have been ascertained. The document would have been understood, as it is a straight forward patent.
The Sankyo patent was discussed above under the heading of novelty. Sankyo discloses the use of the milbemycin B-41 or the avermectin C-076 in combination with another anthelmintic agent. The anthelmintic agent can be praziquantel. There is an example of the use of a mixture of praziquantel and B-41 to treat dogs. In order to establish that the invention lacks an inventive step in the light of the Sankyo patent, three things must be demonstrated:
a) it would have been routine to extrapolate the results from dogs to horses,
b) it would have been routine to extrapolate the results to Australia,
c) it would have been routine to adjust the amount of the active agents to achieve a dose that is effective against both types of parasites in horses.
I have already concluded that species extrapolation is reasonable. This is reinforced by the fact that the specification suggests the compounds will be useful in horses. It is unclear where the tests in the Sankyo patent were carried out, but the fact that it is an Australian patent makes it reasonable to extrapolate the results to Australia. The final question of the dose of each agent is fairly straight forward. It would have been routine to determine the optimal dose. Additionally, Example 3 of Sankyo demonstrates the use of 2.5 and 5 mg/kg of praziquantel and 0.05 mg/kg of B-41. This is close to the dosages of the present application, so a good starting point for routine optimisation has already been disclosed. Thus claim 1 lacks an inventive step. I consider that the entire dosage range of praziquantel would be a matter of routine, as the range is based solely on efficacy of the composition.
Addressing the dependent claims now, the evidence shows that the compounds named in claims 2 to 5 were routine, so they lack an inventive step. The specific quantity specified in claims 6 and 7 appears to be merely the optimised quantity, which is routine. Claims 6 and 7 also lack an inventive step. Finally, the production of a paste is routine, so claim 8 also lacks an inventive step.
5. Manner of manufacture
The law on manner of manufacture has been examined in a number of recent decisions by Australian courts: the High Court in NV PhilipsGloelampenfabriken v Mirabella International Pty Ltd (1995) 183 CLR 655 and Advanced Building Systems Pty Ltd v Ramset Fasteners (Aust) Pty Ltd (1998) 194 CLR 171, the Federal Court in Bristol-Myers Squibb Co v FH Faulding & Co Ltd (2000) 46 IPR 553.
In the Bristol-Myers case, the majority summarised the effect of the Philips case as:
“Philips stands for the proposition (as a matter of construction of the 1990 Act) that if, on the basis of what was known, as revealed on the face of the specification, the invention claimed was obvious or did not involve an inventive step - that is, would be obvious to the hypothetical non-inventive and unimaginative skilled worker in the field (Minnesota at CLR 260 per Barwick CJ) - then the threshold requirement of inventiveness is not met.”
[page 564 at [30]]
It is clear that I must consider whether there is an inventive step in the light of what the specification states is known. What is known is not everything that is stated in the specification:
“Some elaboration, however, is required in relation to what the specification reveals as ‘known’. If a patent application, lodged in Australia, refers to information derived from a number of prior publications referred to in the specification or, generally, to matters which are known, in our view the court - or the commissioner - would ordinarily proceed upon the basis that the knowledge thus described is, in the language of s 7(2) of the 1990 Act, part of ‘the common general knowledge as it existed in the patent area’. In other words, what is disclosed in such terms may be taken as an admission to that effect.”
[Bristol-Myers at page 564 at [30]]
The assessment is based on the common general knowledge as it is presented on the face of the specification. If information is stated to be common general knowledge or can reasonably be inferred to be common general knowledge, then the Commissioner can accept that conclusion without any further evidence. It is not correct to say that every piece of prior art referred to in the specification is part of the common general knowledge.
The specification admits that avermectins and milbemycins are used for the treatment of roundworms (page 1A, second paragraph). The wording used does make it clear whether this is common general knowledge, or public knowledge. The specification makes it plain that praziquantel is a known compound, but it does not seem to be asserted that it is common general knowledge. Given that the two active agents are not asserted to be common general knowledge, it is apparent that there is no lack of invention on the face of the specification.
It was argued by the opponents that a lack of manner of manufacture followed from a lack of obviousness. This is correct if the relevant information appears on the face of the specification. In the present case I found that the invention is obvious in the light of the Lyons article and the Bayer and Sankyo patents. The EP equivalent of Sankyo is mentioned in the specification in the following terms:
“Kitano in the Patent EP 59074 claims associations of macrolide anthelmintic agents and a variety of several anthelmintic agents like benzimidazole, salicylamide and isoquinoline compounds with enhanced anthelmintic activity.”
[page 2]
I considered this passage when discussing the common general knowledge, and concluded that there is no assertion that this was common general knowledge. I think there is no assertion that this is anything more than public knowledge. This argument is also unsuccessful.
An alternative argument was that the present invention is merely a new use of a known substance. This argument is based on the well known case of Commissioner of Patents v Microcell Ltd (1959) 102 CLR 232. Microcell stands for the proposition that
“We have in truth nothing but a claim for the use of a known material in the manufacture of known articles for the purpose of which its known properties make that material suitable. A claim for nothing more than that cannot be subject matter for a patent, and the position cannot be affected either by the fact that nobody thought of doing the thing before, or by the fact that, when somebody did think of doing it, it was found to be a good thing to do.”
[page 251]
I note that Microcell refers to the material as “well-known” and the properties as “known generally”. This seems to be suggesting something more than merely public knowledge. I note that a similar conclusion was reached in Warner-Lambert Co v WM Wrigley Jr Co [1996] APO 4. The first question is whether the “known material” is a mixture of praziquantel and a macrocyclic lactone, or is each of the active agents individually. The invention is the use of a mixture having a ratio of the components that would give the correct dosage rates. While the individual components are well known, it is not clear that a mixture of praziquantel and a macrocyclic lactone was known in the relevant sense. I am satisfied that the invention is not lacking in manner of manufacture.
6. Section 40 issues
(i) Clarity
It was argued that several of the terms in the claims are unclear. I have construed the claims at length earlier in this decision. I found that all terms in the claim were able to be understood, and there are no ambiguities that cannot be resolved.
(ii) Fair basis
It was argued that there is not fair basis for claiming avermectins other than ivermectin and abamectin, nor for claiming milbemycins. The essence of this argument is that it is not possible to predict that other avermectins or milbemycins will display synergy (for instance, see the Wang declaration in reply to the AHPC opposition, paragraph 38, the Beuvry declaration in answer to the AHPC opposition, paragraph 19, the Beuvry declaration in answer to the Merial opposition, paragraph 30 and the Cobb declaration in reply to the AHPC opposition, paragraph 7). I accept that there is evidence that the mechanism of operation of the active agents is unclear, and it is not certain that synergy would be found with other macrocyclic lactones. However, synergy is not the essence of the invention. The invention relates to a broad spectrum anthelmintic, and synergy is merely a bonus (and the absence of synergy would not be outside the nature of the invention). It is reasonable to predict that any avermectin or milbemycin would display activity against roundworms (as this is common general knowledge), and result in a broad spectrum anthelmintic activity. The claims are fairly based in this regard.

It was also argued that the dosage rate is a relative value, not absolute value (based on the evidence of Mr Beuvry). However, the exact statement made by Mr Beuvry is
“the relevance of the results given in examples 10 and 11 in Patent application 691990 does not lay in the ‘absolute’ values, but in the ‘relative’ values of removal levels of Anoplocephala perfoliata which have been obtained depending on whether the Praziquantel is administered alone or in combination with Abamectin or Ivermectin”
[Beuvry declaration in answer to the Merial opposition, paragraph 9]
The efficacy of the compositions is assessed relative to the agents individually, but the dosages are absolute. The dosage rates in the claims are fairly based.
Finally, it was argued that the claims are not fairly based because they are not limited to synergistic compositions. As I explained above, the essence of the invention is not synergy, but broad spectrum anthelmintic activity. It is immaterial that the claims are not limited to synergistic compositions.
I found that the term “effective dose” would be construed as a dose that is effective for the treatment of A. perfoliata, whereas the intended meaning is effective for the treatment of roundworms. As a consequence, claim 1 is not fairly based on the description.
A different issue of fair basis is raised by the evidence introduced under regulation 5.11, and is discussed separately below.
(iii) Defines the invention
It was argued that the claims do not define the synergy and how to achieve it. In my opinion, the specification asserts that synergy is the result of using 0.5 to 2.0 mg/kg of praziquantel in combination with an avermectin or milbemycin. The claims define the invention in these terms, so the claims define the invention in this regard. Synergy is an inherent feature of the invention as claimed.
As already noted, claim 1 does not define the invention because the term “effective dose” is not qualified as effective to treat roundworms.
(iv) Full description
The requirement for full description is a requirement to disclose the invention to a technical person.
“The specification contains a full description if it makes the nature of the invention plain to persons having reasonably competent knowledge of the subject and also makes it plain, to persons having reasonable skill, how to perform the invention”
[Patent Gesellschaft AG v Saudi Livestock Transport and Trading Co (1996) 37 IPR 523 at 530]
I consider that the specification provides sufficient information for a person to prepare compositions and use them for the treatment of horses. I am satisfied that the specification meets the requirement for full description.
7. Matters raised under regulation 5.11
Prior to the hearing I informed the parties of a declaration by Michael Ffloyd Forster that was served as evidence in reply in relation to an extension of term of petty patent number 711820 in the name of Ashmont Holdings Ltd. Mr Forster is listed as an inventor of the present application, and parts of his declaration deal directly with the present application. I provided the parties with a copy of the declaration. At the hearing I gave a direction allowing the parties time to serve evidence in relation to the matters raised by Mr Forster, and time to file written submissions.
Mr Forster made statements addressing two matters. Firstly, he made comments relating to the entitlement of Virbac. Secondly, he made comments relating to the importance of the solvent system of the composition, which raises issues of compliance with section 40. Although the issue of entitlement has not been raised by either opponent, I am entitled to take it into account pursuant to section 60(3). I will quote the relevant parts of Mr Forster’s declaration.
“5. Between 1993 and 1995 Virbac and Ancare New Zealand Ltd (‘Ancare’) worked together on a project Speedwell. …
7. At the time of the Speedwell project I was head of research and development at Virbac. Colin Harvey, one of the directors of Ancare, and I came up with the idea of co developing an anthelmintic horse paste. We worked in close cooperation in terms of the formulation and approach we should take to developing the product. It was agreed that Ancare would share half of the development costs with Virbac. At the inception of the project it was clear that patentable material was likely to result from the project. Because of this there was a natural assumption that the information shared would be kept confidential. An offer proposing the terms of the project was sent to Virbac by Colin Harvey of Ancare on the 23 December 1993. The letter also outlined some proposed formulations for various projects including Speedwell. I annex a copy of that agreement as MF-2.
8. In terms of development of the paste, it would be fair to say that it was Colin Harvey who developed the solvent system which is used in the Virbac patent. I, on behalf of Virbac contributed the paste formulation. It was truly a joint effort.
9. I should emphasize the importance of the solvent system in the Virbac patent. The system allows both praziquantel and avermectins to be solubilized. This is crucial to the patent as the avermectin family is not systemically active unless it is dissolved. A suspension will not work in the animal.
10. Virbac concentrated on the idea of a horse paste and attempted to show synergy between praziquantel and an avermectin or a milbemycin in the treatment of horse tapeworms. This can be seen as the key disclosure in the Virbac patent. See page 2, 4^th paragraph of the patent.
11. Although I left Virbac’s employment before the Virbac patent was prepared,
12. I am still listed as an inventor, but I note that although Colin Harvey developed the solvent system, he is not listed as an inventor. I am unsure why Colin Harvey would not be named as an inventor on the Virbac patent when the solvent system he developed plays such an important part in the working of the invention.
13. I believe that the solvent system disclosed to Virbac by Ancare New Zealand and disclosed in the Virbac patent was made in confidence, and that the disclosure in the specification was made in breach of that confidence.”
Virbac’s further evidence in relation to these matters included a declaration by Mr Beuvry, who declared as follows:
“6. I worked within the team of Virbac Australia Pty’s research and development Ltd from September 1993 until March 1995.
Within the framework of my functions, I participated in the research meetings that were held regularly and allowed the teams of R&D to review the current projects and to discuss the new projects of research and development. I realized experimental protocols, set up and followed the clinical studies and collaborated closely with the people in charge of the formulation and of the galenic development, of the pharmaco-toxicology as well as the clinical development in Australia as well as at Virbac headquarters in France.
7. From December 1993 I was particularly in charge of all the projects of development of new products containing abamectin for horses, pets, sheep and cattle.
8. I worked then actively on the development of two anthelmintic oral pastes for horses, the one based on abamectin only (EQUIMINTH project) and the other one based on a combination of abamectin and praziquantel (EQUIMAX project).
9. For the formulation of these products for horses, we used the Virbac know how in the field of oral pastes for horses. We choose a well known aqueous pasty base, OXIMINTH (anthelmintic oral paste for horses sold for years by Virbac in Australia and in many countries throughout the world). This product contains Diethylene glycol, palmito stearate, sodium metabisulfite, sorbitol and water, and these ingredients were privileged because they provide a stable pasty shape with well established toxicological and pharmacological properties for horses (see Annex VB-2002-1). But the actives had to retain their quality inside the final formulation in order to be able to exert the synergy in the animal. Consequently, we had to fit the base to two actives, with a specific chemical nature each, in combination. The two actives had never been formulated together in a paste at the time of our invention. We knew the avermectin and milbemycin compounds are unstable in water.
10. We decided to incorporate into the aqueous pasty base glycerol formal, polyethylene glycol and benzyl alcohol, to stabilize the abamectin compound.
11. Finally, we added some oatmeal, a thickening agent coming to compensate for the loss in oxibendazole with regard to the original OXIMINTH formulation and which also plays the role of flavoring agent and presents in particular the advantage to reduce the bitterness of the praziquantel in the formula.
12. Colin Harvey was not involved in the idea or decision to formulate the paste as set out in the preceding two paragraph.
13. This formulation was so finalized within the framework of the development of products on base of abamectin only (which resulted in the veterinary medicinal product called EQUIMINTH) and on base of abamectin and praziquantel. This formulation showed itself satisfactory in term of stability, efficiency and tolerance for the candidate product containing only abamectin as active ingredient as well as for the candidate product containing the combination of abamectin and praziquantel without solubilising totally the praziquantel. …
16. It is not necessary the praziquantel to be solubilized for the synergy to occur. This treatment allows controlling and treating infestations by A. perfoliata with a very high efficacy (100%) because of the synergism existing between the active ingredients. In the oral paste formulations for horses as shown in the examples 1 to 5 in the patent specification AU691990, praziquantel is not totally dissolved and one can see crystals of praziquantel in the composition when using an optical microscope (see Annex VB-2002-2). This formulation demonstrated synergy in the trials we made that are shown in the patent specification. Consequently, our invention is not based at all on the need the praziquantel to be solubilized as such as described in the patent specification AU711820.”
Virbac also filed a declaration by Mr Blackhall, the Managing Director of Virbac (Australia), who declared:
“8. The ‘Speedwell’ project however was never related to a product wherein Praziquantel was to be combined with Abamectin.
9. The first mention in my diary of a product wherein Abamectin and Praziquantel would be combined is on an entry for the 1^st March 1994 which relates to a meeting between myself, Michael Forster, Vincent Beuvry and Bill Blackhall [I take this to be a second reference to Mr Blackhall, and not a fourth person]. My diary shows that at the meeting on that date it was resolved that Vincent Beuvry would determine if the combination of actives was feasible in relation to a wormer for horses.
10. My diary shows an entry on 28^th June 1994 to the effect that Vincent Beuvry reported to me for the first time that a horse wormer based on Praziquantel and Abamectin was feasible.
11. On 17^th August 1994 my diary shows that Mr Colin Harvey of Ancare New Zealand Limited visited our premises at Peakhurst near Sydney and that he was told of our work with a Praziquantel and Abamectin based horse wormer and furthermore offered access to our research in relation to such a product. This was the first time that anyone from Ancare New Zealand Limited was advised of our proposal to develop and market a product based on the technology of Patent application 691990 being a paste utilising Praziquantel and Abamectin as actives. …
17. With reference to the second page of annexure ‘MFF-2’ to Mr Forster’s declaration I have instructed personnel within my company to check our records in order to obtain our copy of this facsimile supposedly dated 23^rd December 1993 although no such facsimile has been located. On my copies of said facsimile annexed to Mr Forster’s declaration the date on the first page of annexure ‘MFF-2’ is illegible as the year could be 93 or 95. Furthermore the third page of the annexure appears to bear a date in 1994 with the month illegible. ”

100. On 26 September 2002 I notified all parties that some of the statements made by Mr Blackhall in paragraphs 11 and 17 of his declaration are inconsistent with other evidence on file in relation to petty patent 711820. Specifically, a declaration by Colin Manson Harvey dated 2 June 2000 contains exhibits that are relevant to statements made by Mr Blackhall. I invited the parties to include comments in relation to the Harvey evidence. Written submissions were provided on behalf of Virbac and AHPC.
101. In considering this evidence I have attempted, if possible, to accept all evidence as accurate. I note that Mr Blackhall attacks the credibility of Mr Forster (paragraph 15 of the Blackhall declaration). Mr Blenkinship reinforced this challenge in his written submissions. This attack relates to paragraph 11 of Mr Forster's declaration, where he says he left Virbac’s employment before the patent was prepared. Mr Blackhall points out that Mr Forster was employed by Virbac until 11 September 1995, and provides a number of Exhibits to support this point. The present application was filed at the Patent Office on 28 November 1995, which is clearly after the date that Mr Forster left Virbac. It appears that Mr Blackhall has mistaken the filing date of the provisional application (PM 9699) with which the present application is associated for the date of filing of the present application. This is an easy mistake for a person not familiar with patents, and I do not consider that it should be taken as reflecting on the credit of Mr Blackhall. Mr Blenkinship pointed out that Mr Forster left Virbac “under less than savoury circumstances”, and this is supported by Mr Blackhall’s declaration. I have no basis for concluding that this has poisoned Mr Forster’s evidence. However, there are clear inconsistencies between Mr Blackhall and Mr Harvey which cannot be reconciled, so I have considered their evidence in detail in the following section.
(i) Entitlement
102. Mr Forster and Mr Beuvry are listed as the inventors of the present invention. Mr Harvey is not listed as an inventor, but there are indications that he may have been an inventor. None of the declarations totally clarify the situation. It appears that there are two ways in which Mr Harvey might have contributed to the invention: the first is through the suggestion of a formulation before the development work started, and the second is by involvement in the development work.
103. It is agreed that there was a relationship between Virbac and Ancare, and that there was a project called Speedwell. It also appears that the purpose of the Speedwell project was not the development of a praziquantel-abamectin product. However, it may be that within that relationship information was communicated or work was done that is relevant to the present application.
104. It appears to be Virbac’s assertion that the idea of combining praziquantel and abamectin first occurred on 1 March 1994. On the other hand, there is evidence that Mr Harvey communicated with Virbac by facsimile on 23 December 1993. While Mr Blackhall could not locate his copy of this facsimile, it is clear that he did receive the facsimile. Exhibit CMH-2 of the Harvey declaration dated 2 June 2000 filed in relation to petty patent 711820 is a copy of a facsimile from Mr Blackhall acknowledging receipt of a facsimile of that date from Mr Harvey. Mr Blenkinship’s written submissions included a copy of an email from Mr Blackhall which includes the following passage:
“7. On 23^rd December 1993 Colin Harvey faxed his suggestion to jointly develop abamectin formulations.
8. On 14^th January 1994 after returning from my vacation I replied to Colin Harvey by fax. The joint developments were for sheep and cattle. My fax reinforces that the horse and dog developments were Virbac projects. There is no suggestion or inference that the Virbac projects incorporated combination products for horses or dogs. I acknowledge these two documents.”

It is clear that Mr Harvey sent a facsimile in December 1993, and that the facsimile was received by Mr Blackhall. It is immaterial that Virbac are now unable to locate their copy of the facsimile.
105. What was the content of the facsimile as received by Mr Blackhall? The email from Mr Blackhall attached to the submissions from Mr Blenkinship now acknowledges that Mr Harvey did communicate proposed products in his facsimile of December 1993. The nature of Mr Blackhall’s facsimile response (Exhibit CMH-2) makes it clear that the facsimile from Mr Harvey included a proposal that was outside the agreement with Ancare (i.e. not part of the Speedwell project). It is clear that the facsimile received by Mr Blackhall was the same as that appearing in the Forster declaration.
106. The Harvey facsimile (which appears as MFF-2 and CMH-1) contains two pages of proposed compositions. The composition of significance for the present opposition is the single composition on the last page of the facsimile, which is as follows:
“Formulation Abamectin - Praziquantel Paste for Horse
1 ml/50 mg - 30 ml syringe
Abamectin (Avermectin B1)  4 g
Praziquantel  50 g
Diethylene Glycol Palmito Stearate  80 g
Oat Meal Flour  250 g
Sodium metabisulfite  1 g
Sorbitol solution (Non-crystallising)  120 g
Glycerol formal  60 ml
Methyl Hydrobenzoate  0.5 g
Propyl Hydrobenzoate  0.05 g
Benzyl alcohol  10 g
Purified water  q.s. to 1 litre”

Clearly this is a praziquantel-abamectin composition. I accept that this was probably outside the scope of the Speedwell project. It could be argued that although Mr Harvey’s facsimile was received, it was not an input to the development of the present invention. At this point I note the composition of Example 4 of the present specification:
Abamectin (Avermectin B1)  4 g
Praziquantel  50 g
Diethylene Glycol Palmito Stearate  80 g
Sodium metabisulfite  1 g
Sorbitol solution (non-crystallising)  120 g
Glycerol formal  60 ml
Polyethylene glycol 400  60 ml
Methyl Hydroxybenzoate  0.5 g
Propyl Hydroxybenzoate  0.05 g
Benzyl alcohol  10 g
Oat Meal Flour  300 g
Purified water  q.s. to 1 litre

I note that a “hydrobenzoate” is the same as a “hydroxybenzoate”.
107. The unavoidable observation is that this is nearly identical to the composition in the Harvey facsimile. Mr Beuvry stated that Virbac developed the compositions of the present application by modifying the OXIMINTH product. Exhibit VB-2002-1 of the Beuvry declaration identifies the composition of OXIMINTH as:
Oxibendazole  5.0 g
Diethylene glycol palmito stearate     1.5 g
Sodium bisulfite BP  25.0 mg
Sorbitol EP  3.08 g
Purified water EP   q.s. 25.0 ml

The path from OXIMINTH to the composition in Example 4 involves removing the oxibendazole component, and adding the new active ingredients (abamectin and praziquantel) and six extra components (glycerol formal, polyethylene glycol, benzyl alcohol, oatmeal, methyl hydroxybenzoate and propyl hydroxybenzoate) and determining the desired quantities (as noted in paragraphs 9 to 11 of the Beuvry declaration). My reaction is that this appears to be a substantial change in the composition.
108. On the other hand the composition in Mr Harvey’s facsimile and Example 4 differ only in the amount of oat meal flour and the inclusion of 60 ml of polyethylene glycol 400, which is added as an extra stabiliser. It is far more likely that Mr Harvey’s facsimile was consciously or sub-consciously an input into the development of the present invention.
109. The second issue is whether Mr Harvey played an active role in the development of the praziquantel-abamectin product subsequent to sending the facsimile in December 1993. Mr Forster says that Mr Harvey developed the solvent system, but he is otherwise silent on the exact role played by Mr Harvey. Mr Blackhall and Mr Beuvry declare that Mr Harvey was not involved in the development of the praziquantel-abamectin product. Mr Beuvry states simply that Mr Harvey “was not involved in the idea or decision to formulate the paste” (paragraph 12). The evidence does not establish what role (if any) Mr Harvey played in the development of the product. On balance I not satisfied that Mr Harvey played any active role in the development stage.

110. I conclude that Mr Harvey’s proposal for a praziquantel-abamectin paste was known to Virbac in December 1993. Although this was outside the scope of the Speedwell project, it was known to Virbac and it is likely that it was either consciously or sub-consciously an input to the work that seems to have commenced on 1 March 1994. In Harris v CSIRO (1993) 26 IPR 469 at 488 the Deputy Commissioner resolved the question of joint inventorship by asking whether the invention would have occurred without the input of the other person (albeit unknowingly at the time). It seems improbable that the composition of Example 4 would have occurred without the input from Mr Harvey. However, I cannot say whether the more general idea or any of the other specific examples would have occurred without the input of Mr Harvey. I am satisfied that Mr Harvey is a joint inventor in respect of the invention as it appears in Example 4. This means that Mr Harvey is an inventor in relation to those claims that cover the matter of Example 4: claims 1, 2, 3, 6 and 8.
(ii) Fair basis / defining the invention
111. The second issue raised by the Forster declaration is the assertion that the solvent system is essential to the invention. If this is true, then the claims as they stand are not fairly based and do not define the invention.
112. The comments in the Forster declaration are consistent with comments that are found in several declarations to the effect that the results obtained depend on the way the tests are done. For instance, Dr Jenkins (a declarant for Virbac) declared that it is illogical to compare results from different tests:
“It is totally beyond scientific logic to critically compare the results in the opposed application with data from two experiments conducted under totally different conditions in different parts of the world.”
[Jenkins declaration in answer to the AHPC opposition, paragraph 40]

It follows that the results obtained in a test under one set of conditions cannot be used to predict what will happen in tests under a different set of conditions. In particular, Dr Jenkins agrees that different excipients can influence the efficacy of an active agent (Jenkins declaration in answer to the AHPC opposition, paragraph 41). This is made clear by Mr Beuvry (who is listed as an inventor of the present application):
“The efficacy of an active ingredient on an internal parasite is a variable depending notably on the excipients with which the active ingredient is mixed, the pharmaceutical form of the composition and the route of administration of the composition.”
[Beuvry declaration in answer to the AHPC opposition, paragraph 11]

Mr Beuvry’s declaration in further evidence makes it clear that the praziquantel is not totally dissolved in the compositions of Examples 1 to 5. However, it is apparent that these compositions are still effective despite the (at least partial) insolubility of the praziquantel. Mr Forster states that avermectins are not systemically active unless dissolved. However, I note that in the Sankyo patent it is reported that gelatin capsules of B-41D and praziquantel are effective in dogs. At page 20 of the Sankyo patent it is made clear that capsules are a solid dosage form. I note that the present application exemplifies tablets of abamectin and praziquantel, but there are no tables that show that they are effective (see page 9 of the specification). Is it reasonable to conclude that a solid form of the active ingredients would be likely to be effective? I believe the evidence is clear that solid formulations (or incompletely dissolved formulations) can be effective, but presumably the active ingredients need to dissolve in vivo in order to be effective. Mr Forster would appear to have stressed a different aspect of the avermectin pharmacology. A dissolved formulation might be expected to be more effective, as the active agent is more readily available, but it is not fair to say that a solid form would be ineffective.
113. I conclude that the nature of the composition will likely impact on the precise efficacy level, but it is not essential that the active agents are dissolved in a carrier. It follows that the claims do not have to be limited to the nature of the composition.
8. Conclusion
114. Claims 1 to 8 lack an inventive step in the light of the common general knowledge, the Lyons article and the Bayer and Sankyo patents. Claim 1 is not fairly based and does not define the invention because the term “effective dose” is not qualified as effective to treat roundworms. In addition, there is a lack of entitlement in relation to the third inventor (Colin Manson Harvey) who is an inventor in respect of claims 1, 2, 3, 6 and 8. At the hearing there was some discussion of whether there would be an opportunity to propose amendments in the event that the opposition was successful, and I indicated that it was normal practice to allow the opportunity to propose amendments. I believe there is a legitimate expectation of the opportunity to propose amendments, even though it is hard to imagine what amendments could overcome the inventive step problem. I allow Virbac 60 days from the date of this decision to propose amendments.
9. Costs
115. I allow the parties 30 days from the date of this decision to file written submissions in relation to costs.
Dr S.D.Barker
Delegate of the Commissioner of Patents
Patent attorneys for the applicant : Barker Blenkinship & Associates
Patent attorneys for AHCP : Davies Collison Cave
Patent attorneys for Merial : F.B.Rice & Co

ANNEX: Claims of 691990
1.        A method for controlling and treating infestations by Anoplocephala perfoliata in equine animals comprising orally administering to said animals a composition comprising a dose of 0.5 to 2.0 mg of praziquantel per kilogram of animal body weight together with an effective dose of an anthelmintic agent selected from avermectins or milbemycins or derivatives thereof.
2.        A method according to claim 1 hereof wherein the anthelmintic agent is an avermectin.
3.        A method according to claim 2 hereof wherein the avermectin is abamectin.
4.        A method according to claim 2 hereof wherein the anthelmintic agent is ivermectin.
5.        A method according to claim 1 hereof wherein the anthelmintic agent is moxidectin.
6.        A method in accordance with claim 3 hereof wherein the abamectin is administered at a dose of about 0.2 mg per kilogram of animal body weight.
7.        A method in accordance with claim 4 hereof wherein the ivermectin is administered at a dose of about 0.2 mg per kilogram of animal body weight.
8.        A method in accordance with any one of the preceding claims wherein the composition is administered in the form of a paste.

Praziquantel (mg/kg)	Abamectin (mg/kg)	Efficacy against A. perfoliata
0.5	0.2	89
1	0.2	100
2	0.2	100

Praziquantel (mg/kg)	Ivermectin (mg/kg)	Efficacy against A. perfoliata
0.5	0.2	68
1	0.2	91
2	0.2	100

Praziquantel (mg/kg)	Milbemycin B-41D (mg/kg)	Efficacy against T. vulpis	Efficacy against D. caninum
2.5	0.05	100	100
5	0.05	100	100

Dosage rate of praziquantel (mg/kg)	Route of administration	Number of horses tested	Percentage removal of A. perfoliata	Percentage of horses having ≥ 90% removal of A. perfoliata
0.75	IO	11	82 - 100	91
1.0	IO	2	100 - 100	100
1.0	ST	6	89 - 100	83

[2002] APO 48

12 December 2002