Federal Court invalidates Novartis’ patent term extension for Entresto®

In Novartis AG v Pharmacor Pty Limited (No 3) [2024] FCA 1307, the Federal Court invalidated Novartis’ patent term extension (PTE) for Patent No. 2003206738 based on the registration of Entresto®. A key finding of the Court was that claims directed to a pharmaceutical composition comprising two active pharmaceutical ingredients (APIs) did not encompass an API in the form of a complex.

Case overview and key issues

Novartis sued Pharmacor for infringement of Patent No. 2003206738, the term of which had been extended to 16 January 2028 based on the approval of Entresto®. Pharmacor challenged both the infringement claim and the validity of the PTE.

The claims are directed to a pharmaceutical composition comprising:

• the AT1-antagonist valsartan or a pharmaceutically acceptable salt thereof;
• the NEP inhibitor sacubitril or sacubitrilat or a pharmaceutically acceptable salt thereof; and
• a pharmaceutically acceptable carrier.

Entresto® contains “TSVH”, a single crystalline complex of the anionic forms of sacubitril and valsartan.

The central issue was whether the pharmaceutical composition of claim 1 encompassed TSVH, the API of Entresto®.

To apply for PTE in Australia, 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, goods containing, or consisting of, the substance must be included in the Australian Register of Therapeutic Goods (ARTG).

Accordingly, the Court had to subsequently determine whether (i) a pharmaceutical substances per se was in substance disclosed in the specification and fell within the scope of the claim, and (ii) if Entresto® contained or consisted of those substances.

Arguments presented by the parties

Novartis argued that the claims encompassed any combination of valsartan and sacubitril, regardless of their form or association. Novartis contended that TSVH, as a complex of valsartan and sacubitril, fell within the scope of the claim.

Novartis further submitted that even if Entresto® were found to contain a single active ingredient, it nevertheless “contains or consists of” a combination of sacubitril and valsartan in anionic form and anionic sacubitril and valsartan are “identifiable” in TSVH’s crystal structure.

Pharmacor contended that the claim was limited to compositions comprising separate valsartan and sacubitril components and did not encompass TSVH, which is a distinct chemical entity.

Pharmacor submitted that, if its construction of claim 1 was accepted, then the PTE was not valid because Entresto® does not contain or consist of: (a) valsartan or a pharmaceutically acceptable salt thereof; (b) sacubitril or a pharmaceutically acceptable salt thereof; and (c) a pharmaceutically acceptable carrier, but rather consists of the distinct entity, TSVH.

Federal Court’s ruling and reasoning

The Court agreed with Pharmacor’s construction, finding that the claim did not encompass TSVH. The Court reasoned that a complex such as TSVH is a unique entity with its own properties and is not merely a combination of its constituent components. In doing so, the Court construed claim 1 to encompass a composition in which the component of integer (i) and the component of integer (ii) are each present as separate components.

The Court held that the PTE was invalid because TSVH, as a distinct chemical entity, was not disclosed or envisaged in the specification and did not fall within the scope of the claim. Entresto® was found to not contain or consist of the valsartan and sacubitril salts in their separate form.

Strategic takeaways for pharmaceutical patentees

This decision has implications for pharmaceutical patent drafting, prosecution, and PTE strategy. The Court’s construction shows that composition claims comprising separate actives may not be construed broadly to encompass those actives in complexes and other forms giving rise to distinct chemical entities. The decision may also have implications for “large molecules”, particularly when considering the incorporation of antigen binding domains into follow on products.

The lengthy regulatory approval process, often spanning several years, can lead to evolving drug product formulations. In many cases, the final approved product may differ from the initial disclosure in the original patent. To mitigate this risk, filing second-generation patents to cover new formulations, particularly for novel pharmaceutical forms, can be a prudent strategy.

A robust divisional strategy is also essential. Utilising divisional applications can provide patentees with the opportunity to pursue claims that align with prescribing information at a later date. Australian patent law provides flexibility in this regard, allowing for the filing of multiple divisionals with overlapping claim scope. Additionally, patentees should consider carving out separate products into distinct divisional applications, as discussed in detail here.

We note that the decision remains subject to appeal, and we will continue to monitor developments closely. This underscores the importance of maintaining a flexible divisional strategy to adapt to evolving legal and commercial landscapes.

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