Overview of Defactinib and Patent AU2022201741
Defactinib (VS-6063) is an investigational oral inhibitor of focal adhesion kinase (FAK), a protein implicated in tumor metastasis and resistance to chemotherapy. As of April 2025, Defactinib is in Phase 3 clinical trials for recurrent low-grade serous ovarian cancer, with additional studies exploring its efficacy in pancreatic, non-small cell lung, and other RAS/MAPK-driven cancers[15][17][18]. Australian Patent AU2022201741, expiring on June 3, 2030, forms part of a global patent family comprising 33 U.S. patents and 276 international filings[15]. This patent is critical to protecting Defactinib’s commercial prospects in Australia, particularly given its potential as a backbone therapy in combination regimens[16].
Key Aspects of Patent Scope and Claims
1. Eligibility for Pharmaceutical Patent Term Extension (PTE)
Under Australian law, a standard patent covering a “pharmaceutical substance per se” may qualify for a PTE of up to five years[12]. To meet this requirement, claims must define the substance itself without process, temporal, or environmental limitations. Recent Federal Court decisions clarify that:
- Product claims with process or result limitations (e.g., sustained-release formulations) may still qualify if the claim’s substance is central[3].
- The PTE term is calculated based on the earliest regulatory approval date of any pharmaceutical substance disclosed in the patent, including third-party products[2][12].
For AU2022201741, eligibility hinges on whether its claims are directed to Defactinib as a compound, formulation, or method of use. If the claims encompass combination therapies (e.g., Defactinib + pembrolizumab + gemcitabine)[17], they may face scrutiny unless framed as product claims. The patent’s inclusion in clinical trials for combination regimens[16] suggests method-of-use claims, which are ineligible for PTE unless tied to a novel formulation[12].
2. Claim Structure and Validity Risks
The patent’s enforceability depends on adherence to Australia’s "best method" requirement, which mandates disclosure of the optimal known embodiment of the invention[4]. For example:
- If AU2022201741 claims a specific dosing regimen (e.g., 400 mg BID) but omits pharmacokinetic data supporting this dose, it risks invalidation for insufficient disclosure[4].
- Claims limited by functional characteristics (e.g., “FAK inhibition with IC50 ≤ 10 nM”) must enable a skilled person to determine infringement without undue experimentation[3].
Recent litigation in Sun Pharma v Otsuka highlighted that claims with result-based limitations (e.g., “release duration of one week”) require clear guidance in the specification to avoid ambiguity[3]. AU2022201741’s claims must balance breadth with specificity to withstand challenges.
Patent Landscape and Competitive Threats
1. Global and Australian Patent Holdings
Defactinib’s global portfolio includes patents covering:
- Compound claims: Protects the chemical structure of Defactinib (e.g., US-10016435-B2)[6].
- Formulation claims: Covers oral dosage forms, sustained-release technologies, and combination kits[15].
- Method-of-use claims: Targets specific indications (e.g., KRAS-mutant cancers)[16][18].
In Australia, competitors may challenge AU2022201741 via:
- Divisional applications: If the patent broadly claims FAK inhibitors, generics could file divisional patents narrowing the scope.
- Paragraph IV-like challenges: While Australia lacks an exact equivalent to the U.S. Hatch-Waxman system, generic manufacturers may seek to invalidate claims through pre-grant opposition or post-grant review[1][12].
2. Litigation Precedents and Strategic Implications
The Full Federal Court’s decisions in Ono and MSD underscore the risks of overlapping patent claims:
- A patent covering multiple substances (e.g., Defactinib and a combination partner) may have its PTE term reduced if another product in its scope received earlier regulatory approval[2][12].
- To mitigate this, patentees often file divisional applications to isolate key substances[12]. For AU2022201741, segregating Defactinib monotherapy claims from combination therapy claims could preserve PTE eligibility.
Market Exclusivity and Clinical Development
Defactinib’s commercial viability in Australia will depend on:
- Clinical Success: Phase 3 trials showing improved progression-free survival in ovarian cancer (NCT04625270) could justify premium pricing[15][16].
- Regulatory Strategy: Aligning patent expiration (2030) with potential PTE grants could extend exclusivity to 2035, contingent on ARTG approval timelines[12].
- Generic Competition: Post-2030, generics may leverage §119B of the Patents Act to stockpile Defactinib, necessitating lifecycle management (e.g., follow-on formulations)[12].
Conclusion
Patent AU2022201741 is a linchpin in Defactinib’s Australian market strategy. Its scope must balance broad therapeutic coverage with precise claim drafting to withstand validity challenges. The evolving jurisprudence on PTEs and functional claiming necessitates proactive portfolio management, including divisional filings and global alignment. With clinical trials ongoing, stakeholders should monitor competitive patent filings and regulatory developments to optimize Defactinib’s lifecycle.
Key Takeaways
- AU2022201741’s PTE eligibility depends on claim structure and regulatory approval timelines.
- Competitors may challenge the patent via divisional applications or invalidity actions.
- Clinical success in ongoing trials will influence market exclusivity and generic entry strategies.
FAQs
-
How does Australia’s PTE system differ from the U.S. Orange Book?
Australia bases PTEs on the earliest approved substance in a patent, whereas the U.S. allows multiple patents per drug with varying expiry dates[2][5].
-
Can process-limited claims in AU2022201741 qualify for PTE?
Yes, if the claims are fundamentally product-centric per Sun Pharma v Otsuka[3].
-
What clinical data supports Defactinib’s patent claims?
Phase 1/2 trials show a 80% disease control rate in pancreatic cancer[17], reinforcing its utility.
-
How might generics enter the Australian market post-2030?
Generics could file under §119B for early stockpiling or challenge the patent’s validity[12].
-
Are combination therapies covered under AU2022201741?
Likely, but method-of-use claims may not qualify for PTE unless tied to a novel formulation[12].
"Claims defining a pharmaceutical substance 'for use' require careful consideration and may not be eligible to support a PTE or render any resultant PTE susceptible to challenge." – *Spruson & Ferguson Analysis on PTEs* [12]
References
- https://www.drugpatentwatch.com/p/generic-entry-opportunity-date/Australia
- https://www.spruson.com/full-federal-court-doubles-down-on-pharmaceutical-patent-term-extensions/
- https://dcc.com/news-and-insights/process-or-result-limitations-in-a-product-claim-not-a-barrier-to-pte-in-australia/
- https://www.jamesandwells.com/intl/best-method-requirement-in-australian-and-new-zealand-patent-law/
- https://www.fdli.org/wp-content/uploads/2022/08/7-Darrow-and-Mai.pdf
- https://pubchem.ncbi.nlm.nih.gov/patent/US-10016435-B2
- https://www.claimscopeproject.net/pls
- https://www.griffithhack.com/insights/publications/australian-innovation-patents-gone-but-not-forgotten/
- https://inspire.wipo.int/auspat
- https://asiaiplaw.com/article/ip-australia-launches-new-patent-search-tool
- https://curity.io/resources/learn/scopes-vs-claims/
- https://www.spruson.com/pharmaceutical-patent-term-extension-in-australia/
- https://www.wipo.int/publications/en/series/index.jsp?id=137
- https://patents.google.com/patent/AU2022900382A0/en
- https://www.drugpatentwatch.com/p/drugs-in-development/drugname/Defactinib
- https://www.biospace.com/verastem-oncology-announces-preclinical-presentations-for-new-oral-g12d-inhibitor-and-for-avutometinib-and-defactinib-combination-as-a-backbone-of-therapy-for-ras-mapk-driven-cancers-at-aacr-annual-meeting-2024
- https://pmc.ncbi.nlm.nih.gov/articles/PMC9772237/
- https://pubmed.ncbi.nlm.nih.gov/31739184/
Last updated: 2025-04-23
