The recent Federal Court ruling in Novartis AG v Pharmacor Pty Limited (No 3) [2024] FCA 1307 highlights an increasing trend of challenging patents during the extended term granted based on regulatory approval of pharmaceutical substances. The Court’s decision underscores the complexities of patent claim construction and its implications for pharmaceutical companies seeking to extend their patent protection.
In this case, Justice Yates adopted a claim construction that resulted in the granted claims not covering the pharmaceutical substance used for Novartis AG’s (Novartis) patent term extension (PTE) application, thus causing the PTE to be considered invalidly granted.
Adopting this claim construction also resulted in Pharmacor Pty Limited (Pharmacor) being successful in their defence against infringement of Novartis’s patent.
Background
The case concerned Novartis’s patent for a pharmaceutical composition comprising the angiotensin receptor blocker (ARB) valsartan (or salts thereof) and one of two neutral endopeptidase (NEP) inhibitors – sacubitril and sacubitrilat (or salts thereof) and a pharmaceutically acceptable carrier.
Australian patent No. 2003206738 (patent) was filed on 16 January 2003. The patent was granted on 5 April 2007 with an expiration date of 16 January 2023.
In 2016, Novartis applied for and was granted an extension of patent term until 16 January 2028 on the basis of the Australian Register of Therapeutic Goods (ARTG) registration for Entresto, an oral tablet containing a salt complex of the anionic forms of sacubitril and valsartan, sodium cations, and water molecules in the ratio of 1:1:3:2.5 (the “TSVH complex”) plus excipients.
The TSVH complex was first synthesised in 2006, and was the subject of a separate international patent application (PCT/US2006/043710).[1]
Claim 1 of the patent is as follows:
1. A pharmaceutical composition comprising:
(i) the AT 1-antagonist valsartan or a pharmaceutically acceptable salt thereof;
and
(ii) the NEP inhibitor N-(3-carboxy-1-oxopropyl)-(4S)-p-phenylphenylmethyl)-4-amino-2R-methylbutanoic acid ethyl ester or (2R,4S)-5-Biphenyl-4-yl-4-(3-carboxypropionylamino)-2-methyl-pentanoic acid or pharmaceutically acceptable salts thereof and a pharmaceutically acceptable carrier.
Novartis alleged that Pharmacor threatened to infringe claim 1 of the patent through its intended supply of pharmaceutical products entered on the ARTG, referred to as Valtresto. Valtresto comprises an amorphous complex, termed SVTI, in which valsartan anions, sacubritril anions, and sodium cations are present in a 1:1:3 complex.[2]
Pharmacor denied this infringement allegation and submitted that claim 1 of the patent does not cover a complex, and as such its intended exploitation of Valestro cannot be a threatened infringement of claim 1.[3]
Pharmacor also cross-claimed for revocation of the patent, alleging that claim 1 is invalid on three grounds: failure to disclose the best method, lack of fair basis and lack of an inventive step.[4] In addition, Pharmacor alleged that the PTE granted on 5 December 2016 was wrongly granted and thus sought rectification of the register to remove reference to the term of the patent having been extended, and to record that the term of the patent expired on 16 January 2023.[5]
Construction of claim 1
The core issue about which much of this decision revolved was the construction of claim 1, namely whether integers (i) and (ii) would be satisfied by a salt complex containing the anionic forms of sacubitril/at and valsartan with pharmaceutically acceptable cations (as in Entresto and Valtresto).[6]
In this regard, Novartis sought to argue that claim 1 covered any pharmaceutical composition including a carrier that delivers valsartan and sacubitril/at as the relevant active agents or ingredients.[7]
Further, Novartis submitted that there is nothing in claim 1 which suggests that integer (i) cannot be satisfied by a compound which also satisfies integer (ii), nor is there any limitation that excludes compositions in which there are non-covalent bonds between the valsartan and sacubitril (such as are present in the TSVH complex).[8]
Justice Yates did not accept Novartis’s construction of claim 1, holding that:
Claim 1 does not claim, through integers (i) and (ii), a complex formed from valsartan and sacubitril/at or their pharmaceutically acceptable salts.[9]
Justice Yates found that a complex is a unique, single entity with its own properties, and stated that:[10]
A complex formed from valsartan and sacubitril/at or their pharmaceutically acceptable salts is not: (a) valsartan or a salt of valsartan; (b) sacubitril or a salt of sacubitril; or (c) sacubitrilat or a salt of sacubitrilat. In short, it is none of the things referred to in claim 1.
The Judge further clarified that his construction of claim 1 did not “exclude” a complex, but rather that claim 1 does not claim a complex at all:[11]
…by claiming the pharmaceutical composition in the way it has, Novartis has claimed a composition in which the component of integer (i) and the component of integer (ii) are each present as separate components. One cannot “exclude” that which has not been claimed.
The construction adopted by Justice Yates that claim 1 does not include the TSVH complex or the SVTI complex has consequences for several of the contested issues.[12]
Infringement
In defence of the infringement allegation, Pharmacor submitted that since claim 1 does not cover a complex, its intended sale of Valtresto does not infringe claim 1. The basis for this argument being that this complex is a single salt, rather than the two separate salts required by claim 1.
Despite Novartis disputing this argument, his Honor ultimately found that, in view of the construction adopted for claim 1, exploitation of Valtresto would not infringe the patent.[13]
Yates held that[14]:
Given the construction of claim 1 that I have found, Novartis’s case on infringement fails at the outset, regardless of the validity of claim 1 or whether the term of the patent was validly extended.
Extension of term
Pharmacor also challenged the validity of the extension of term application granted in 2016, alleging that the extension application failed to satisfy one or both of the following sections of the Patents Act 1990 (Cth):[15]
- 70(2)(a): one or more pharmaceutical substances per se must in substance be disclosed in the complete specification of the patent and in substance fall within the scope of the claim or claims of that specification; and
- 70(3)(a): goods containing, or consisting of, the substance must be included in the Australian Register of Therapeutic Goods.
Novartis’s PTE application referred to the “pharmaceutical substance per se” as “a combination of sacubitril and valsartan”. The PTE application stated that the “pharmaceutical substance per se” fell within the scope of the claims and was disclosed in the complete specification because:[16]
A pharmaceutical composition comprising valsartan and sacubitril and a pharmaceutically acceptable carrier is claimed in the patent, for example in claim 1.
In relation to the s 70(3)(a) requirement, Novartis’s PTE application said that the goods containing, or consisting of the pharmaceutical substance included in the ARTG are: [17]
ENTRESTO sacubitril/valsartan (combined as a sodium salt hydrate complex)
His Honor found that s 70(2)(a) had been satisfied, but that the PTE application failed to satisfy s 70(3)(a).[18] The basis for this finding was that for s 70(3)(a), the relevant pharmaceutical substance in Entresto is the TSVH complex – a single crystalline complex that is one salt with a unique set of physiochemical properties.[19]
Justice Yates held that “Entresto does not contain or consist of a “combination” of sacubitril and valsartan”[20] and stated that:[21]
The pharmaceutical substance in Entresto is TSVH. TSVH is not disclosed or even envisaged in the specification. All the relevant experts agree on that. Further, TSVH does not fall within the scope of claim 1. Different pharmaceutical substances are disclosed and claimed in the specification, albeit that they are intended to have the same therapeutic effect as TSVH. But s 70(3)(a) is not satisfied by merely pointing to a different pharmaceutical substance in the registered goods that has the same intended therapeutic effect as the pharmaceutical substance or substances that satisfy s 70(2)(a).
As the PTE application did not meet the requirements of s 70(3)(a), Pharmacor was successful in establishing that the term of the patent should not have been extended.[22]
Validity challenges
The challenges on the grounds of failure to disclose the best method and lack of fair basis were contingent on Justice Yates adopting the construction that claim 1 included complexes such as TSVH and SVTI.
As this was not the construction adopted, and the PTE was found to be invalidly granted (and thus the patent expired in 2023), these challenges and the lack of inventive step challenge were no longer relevant. However, in obiter, Justice Yates chose to address the inventive step challenge advanced by Pharmacor.
Pharmacor’s inventive step challenge relied on the common general knowledge and a pair of prior art documents collectively termed the “Ksander documents”. Given that the patent in suit was filed before the Raising the Bar Act 2012, the question of whether these documents would have been “ascertained, understood and regarded as relevant” by the skilled person was a key issue in consideration.
In view of the evidence, Justice Yates found that the skilled person could be reasonably expected to have ascertained the Ksander documents and regarded them as relevant.[23] Nonetheless, his Honor did not accept that the uninventive skilled person would have had a reasonable expectation that the particular combination (of an ARB and an NEP inhibitor) might well produce a useful therapy. [24] Justice Yates held that this finding was fatal to Pharmacor’s challenge to the validity of claim 1 on the ground of lack of inventive step even before selection of the particular ARB (valsartan) and NEP inhibitor (sacubitril) is considered.[25]
Conclusion
As of the time of writing this article, neither party have filed an appeal to the decision of Justice Yates.
In any event, this decision reinforces that patent applicants must carefully consider the language used when claiming pharmaceutical compositions, to ensure the claims best cover the pharmaceutical product that is ultimately produced.
Additionally, pharmaceutical patent owners should be aware of the growing trend of challenges to pharmaceutical patents during their extended term.
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[1] Novartis at [96]-[100]
[2] Novartis at [101]
[3] Novartis at [226]
[4] Novartis at [7]
[5] Novartis at [9]
[6] Novartis at [171]
[7] Novartis at [176]
[8] Novartis at [188]
[9] Novartis at [198]
[10] Novartis at [199]
[11] Novartis at [223]
[12] Novartis at [172]
[13] Novartis at [249]-[251]
[14] Novartis at [237]
[15] Novartis at [267]
[16] Novartis at [263]
[17] Novartis at [264]
[18] Novartis at [298]
[19] Novartis at [289]
[20] Novartis at [290]
[21] Novartis at [293]
[22] Novartis at [499]
[23] Novartis at [423]
[24] Novartis at [487]-[488]
[25] Novartis at [488]