In a recent decision in Novartis AG v Pharmacor Pty Limited (No 3) [2024] FCA 1307, Justice Yates of the Federal Court of Australia considered whether an application for an extension to the term of a pharmaceutical patent was wrongly granted by IP Australia.

Apart from questions of infringement and validity, the case considered the validity of Novartis’ extension of term application in relation its Australian patent for a blood pressure medication comprising a combination of two actives, sacubitril and valsartan, marketed under the brand name Entresto.

The decision reinforces that for a valid patent term extension application, there must be identity between the pharmaceutical substance disclosed and claimed in the patent and the substance contained in the goods registered in the ARTG.

This decision follows other recent decisions of the Full Federal Court in Commissioner of Patents v Ono Pharmaceutical Co. Ltd [2022] FCAFC 39 and Merck Sharp & Dohme Corp. v Sandoz Pty Ltd  [2022] FCAFC 40, which we covered in previous articles (Part 1 and Part 2), and in which extensions of pharmaceutical patents were found to be invalid.

In each case, the Courts have taken a relatively strict approach to the interpretation of the provisions governing pharmaceutical patent term extensions.  This latest decision reinforces that for a valid patent term extension application, there must be identity between the pharmaceutical substance disclosed and claimed in the patent and the substance contained in the goods registered in the ARTG.

Extension of Term Provisions

Pharmaceutical patent term extensions are governed by s 70 of the Patents Act 1990 (Cth), which permits a patent term extension of up to five years for a patent disclosing and claiming a pharmaceutical substance that is registered in the Australian Register of Therapeutic Goods (ARTG).

Justice Yates referred to Commissioner of Patents v Ono Pharmaceutical Co. Ltd [2022] FCAFC 39, which set out that the validity of extension of term applications involves three inquiries:

1. The first inquiry, in s 70(2), requires that one or more pharmaceutical substances per se must, in substance, be disclosed in the patent and, in substance, fall within the scope of the claims of the patent.
2. The second inquiry, in s 70(3), requires that at least one of the pharmaceutical substances:
   
   1. are contained in, or consist in, goods included in the ARTG (s 70(3)(a)); 
   2. the ARTG registration date must be at least five years after the grant date of the patent (s 70(3)(b)); and
   3. an extension of term application must be filed within six months of the earliest relevant ARTG registration.
3. The third inquiry, in s 70(4), provides that the term of the patent must not have been previously extended.

Justice Yates also noted that the requirement in s 70(2)(a) of “in substance” disclosure is whether there has been a “real and reasonably clear disclosure” of the substance in the patent.

Further, in relation to s 70(3)(a), Justice Yates explained that the relevant factual inquiry is whether the pharmaceutical substance is an “ingredient” of the nominated goods included in the ARTG.

Basis for Challenging the Extension

Pharmacor challenged the validity of the extension application on the basis that the ARTG registration was for a pharmaceutical substance which was not disclosed, in substance, or claimed in the patent.

It argued that the ARTG registration was for a drug product sold under the brand Entresto, which comprises a single crystalline salt of sacubitril and valsartan (termed TSVH) and excipients.  However, the Patent disclosed and claimed two salts, one of valsartan and the other of sacubitril.  

Novartis argued that “a combination of sacubitril and valsartan per se” is disclosed in the specification and, in substance, falls within the scope of claim 1.  Furthermore, the combination is a pharmaceutical substance within the meaning of s.70, because it is a “mixture or compound” of two pharmacologically active agents.  

It further argued that the ARTG registered Entresto product contains a “combination” of two therapeutically active “ingredients”, namely sacubitril and valsartan, and their presence in a complex does not cause valsartan and sacubitril to “lose their identities as distinct molecules and distinct active agents”.

Novartis also argued that the product information (PI) for the Entresto listing on the ARTG says that the “name of the medicine” is “sacubitril and valsartan” and that Entresto tablets contain sacubitril and valsartan “where both drug substances are combined as a sodium hydrate salt complex”.  Notwithstanding Novartis’ argument, the PI also refers to Entresto’s active ingredient as “A salt complex of the anionic forms of sacubitril and valsartan…”, which the Court noted is a single active pharmaceutical ingredient, with a single molecular formula and other characteristics of a single molecule.

Additionally, Novartis argued that expert evidence as to what Entresto contains is not relevant to the s. 70(3) inquiry.  Nevertheless, the experts engaged by both sides to give evidence in the matter noted that the Entresto product consisted of the single molecule TSVH and that there was no actual disclosure of this molecule in the patent and nor did it fall within the scope of the claims.

Reasoning and Decision

In addressing the s. 70(2) inquiry, the Court found that the patent relevantly disclosed and claimed two “pharmaceutical substances per se”.  Firstly, the AT 1-antagonist identified as valsartan or a pharmaceutically acceptable salt of valsartan; second, the NEP inhibitor identified as either sacubitril or a pharmaceutically acceptable salt of sacubitril, or sacubitrilat or a pharmaceutically acceptable salt of sacubitrilat.

In addressing the s. 70(3) inquiry, and in ultimately finding that the extension application was invalid, the Court noted that:

“The extension application was based on Entresto and, despite the language in which Novartis AG chose to couch that application, the relevant pharmaceutical substance in Entresto is TSVH—a single crystalline complex that is one salt with a unique set of physiochemical properties.

Novartis AG’s description in the extension application of the pharmaceutical substance as “a combination of sacubitril and valsartan” is notable for its obscurity.  Entresto does not contain or consist of a “combination” of sacubitril and valsartan unless that description is taken to mean that sacubitril and valsartan, in some form, are inputs in a complexation process that results in the production of a different entity, TSVH, which is then used in Entresto.”

Justice Yates went on to note that for an extension of term application to be valid:

“The pharmaceutical substance or substances that are identified for the purposes of s 70(2) must be the pharmaceutical substance or substances that are considered for the purposes of s 70(3).” 

In other words, there must be identity between the pharmaceutical substance contained in goods included in the ARTG and that the pharmaceutical substance, which is disclosed and claimed in the specification of the patent.

Guidance for Pharmaceutical Patent Term Extension Applications

This decision follows other recent decisions of the Full Federal Court, in which extensions of pharmaceutical patents were found to be invalid.  This recent decision reinforces the strict approach that the Courts are adopting to the provisions governing pharmaceutical patent term extensions.  This latest decision reinforces that for a valid patent term extension application:

1. There must be a “real and reasonably clear disclosure” of a pharmaceutical substance in the patent;
2. That substance must be an “ingredient” of the nominated goods included in the ARTG, and this is a factual enquiry for which expert evidence can be relevant; and
3. There must be identity between the pharmaceutical substance contained in goods included in the ARTG and that the pharmaceutical substance, which is disclosed and claimed in the specification of the patent.

If you have any questions about pharmaceutical patents or extension of term applications in Australia then please contact Daniel McKinley or Catrina Olivera.