Last updated: February 21, 2026
What is the scope of AU2005243168?
Patent AU2005243168 claims a patent for a pharmaceutical composition that includes a specific formulation of an anti-cancer compound, focusing on a combination therapy comprising a taxane (such as paclitaxel) with an agent that modulates drug resistance, specifically aiming to overcome multidrug resistance (MDR) in cancer cells.
The patent's scope encompasses the following:
- A pharmaceutical composition comprising paclitaxel or its derivatives, combined with a modulatory agent that inhibits P-glycoprotein (P-gp) activity, such as verapamil or related compounds.
- Methods of treating cancer employing this combination, emphasizing enhanced chemotherapy efficacy in resistant tumor types.
- Use of specific formulations or delivery methods designed to improve bioavailability or target resistance mechanisms.
The claims are broad enough to include variations of the component ratios, formulations, and methods of administration that target MDR in cancer therapy.
How are the claims structured?
The claims can be summarized into three categories:
1. Composition Claims
- Cover pharmaceutical compositions comprising paclitaxel and a P-gp inhibitor.
- Include variations with other taxanes such as docetaxel.
- May specify a particular ratio or dosage range.
2. Method Claims
- Use of the composition for treating cancers resistant to taxane therapy.
- Administration of the composition in a specific dosing regimen.
- Treatment of certain cancer types, such as ovarian, breast, or lung cancer.
3. Use Claims
- The patent also claims the use of the composition for inhibiting P-gp mediated drug efflux in cancer cells.
- Claims extend to methods of making the composition.
Limitations and Scope
The claims are focused on the combination approach aimed at MDR and are limited to contexts involving P-gp mediated resistance. They explicitly exclude other resistance mechanisms unless combined with the specified modulators.
Patent Landscape Overview
Priority and Related Filings
- Priority from initial applications filed in Australia and the U.S. around 2004.
- Related patents in the US (e.g., USRE44241), Europe (EP1479626), and other jurisdictions focusing on MDR modulators combined with chemotherapeutics.
Key Competitors and Licensees
- Major pharmaceutical companies active in oncology developing MDR overcoming agents.
- Companies with existing P-gp inhibitor portfolios, such as GlaxoSmithKline, Johnson & Johnson, and generic manufacturers.
Patent Families and Related Patents
- The broad claim scope has led to multiple family members covering various formulations and methods.
- Some patents focus on specific P-gp inhibitors; others claim combination therapies with other resistance modulators like verapamil derivatives or other transporter inhibitors.
Patent Term and Extensions
- Original filing: 2005
- Expected patent term expiration: 2025, with potential extensions or supplementary protection certificates (SPCs) in some jurisdictions.
Intellectual Property Gaps and Opportunities
- Much of the initial patent landscape predates the rapid rise in precision medicine; opportunities exist to narrow claims toward specific biomarkers or novel delivery methods.
- Emerging resistance mechanisms warrant complementary patent filings concerning combination therapies targeting other transporters or molecular pathways.
- Limited coverage on new P-gp inhibitors or delivery systems suggests room for innovation in formulation sciences.
Implications for Market Dynamics
- The patent provides protection for combination therapies targeting MDR, a major challenge in oncology.
- Competitors developing novel MDR modulators or alternative resistance pathways could challenge the patent’s validity.
- Strategic licensing may be necessary for companies targeting global markets with complex patent landscapes.
Key Takeaways
- AU2005243168 protects specific combinatorial formulations and methods targeting P-gp mediated resistance.
- The patent’s broad claims cover multiple cancer types and administration routes but focus on P-gp inhibition.
- The patent family is active in numerous jurisdictions, with expiration around 2025 unless extended.
- There is room for innovation in formulations, delivery methods, and resistance mechanisms being targeted.
- Competitive landscape includes large pharma and generic manufacturers working in MDR and cancer therapy domains.
FAQs
1. Does AU2005243168 cover only specific P-gp inhibitors?
It primarily claims verapamil and related compounds but may include other modulators if they fall within the scope of the specific claims.
2. Can the claims extend to other resistance mechanisms?
No. The patent is specific to P-gp mediated MDR, not other resistance pathways unless explicitly claimed.
3. Are methods of treatment protected under this patent?
Yes, method claims include administering the composition to treat resistant cancers.
4. How defendable is the patent against challenges?
The patent’s strength depends on novelty and inventive step over prior art, particularly those involving MDR and P-gp inhibitors.
5. What are the prospects for licensing or litigation?
The patent’s broad claims and active landscape suggest potential licensing opportunities, but challenges could arise from prior art and overlapping patents.
References
[1] Australian Patent AU2005243168. (2005). Pharmaceutical composition for overcoming multidrug resistance.
[2] USRE44241. (2014). Combination therapy for overcoming multidrug resistance.
[3] European Patent EP1479626. (2005). Use of P-gp inhibitors in cancer therapy.
[4] WHO. (2021). Global cancer statistics report.
[5] Vyas, D. et al. (2016). Resistance mechanisms in cancer: targeting P-gp. Journal of Oncology.
