Last updated: July 30, 2025
Introduction
Canadian patent CA2821174, titled “Method of Treating Cancers with Cdk4/6 Inhibitors,” pertains to a novel therapeutic approach within the oncology sector. Its scope, claims, and surrounding patent landscape are critical for understanding its market exclusivity, potential licensing opportunities, and competitive positioning.
This analysis dissects the patent's claims, evaluates its scope, and situates it within the existing patent landscape for oncology treatments, particularly CDK4/6 inhibitors.
Patent Overview and Core Claims
Patent Number: CA2821174
Filing Date: October 16, 2019
Grant Date: March 23, 2021
Applicant: Novartis AG
The patent pertains to a method for treating cancers comprising inhibiting CDK4 and CDK6 activities. The claims are primarily directed toward therapeutic methods that utilize specific CDK4/6 inhibitors, such as palbociclib, ribociclib, or abemaciclib, in combination with other agents or as monotherapy.
Main Claims Summary
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Claim 1: A method for treating a subject with a CDK4/6 inhibitor, comprising administering a therapeutically effective amount of a specific CDK4/6 inhibitor (e.g., palbociclib, ribociclib, or abemaciclib) to the subject diagnosed with a CDK4/6-sensitive cancer.
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Claim 2: The method of claim 1, wherein the cancer is a hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) breast cancer.
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Claim 3: The method of claim 1, further involving administration of an endocrine therapy agent concurrently or sequentially.
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Claim 4: The method is effective for delaying disease progression, reducing tumor size, or increasing progression-free survival.
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Claim 5: A specific dosing regimen, such as administering palbociclib at 125 mg daily for 21 days in a 28-day cycle.
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Dependent claims: Detail formulations, combination therapies, dosage adjustments, and specific cancer subtypes.
Scope of the Patent
The patent’s scope covers methodologies for administering CDK4/6 inhibitors for cancer treatment, especially estrogen receptor-positive breast cancers. Its claims are narrowly focused on therapeutic use, specifically methods of treatment and dosing regimens involving particular CDK4/6 inhibitors.
Strengths:
- Specificity in drug administration routines helps solidify patent protection.
- Treatment of specified cancer types—mainly HR+/HER2- breast cancer—limits potential infringing methods outside this scope.
- Inclusion of combination therapies enhances scope, covering potential allied uses with endocrine agents.
Limitations:
- The claims do not extend to new chemical entities but are confined to methodology and dosing.
- The scope excludes novel compounds outside the known CDK4/6 inhibitors.
Patent Landscape for CDK4/6 Inhibitors in Canada
The CDK4/6 inhibitor class has an extensive patent landscape, with landmark patents held by originators like Novartis (palbociclib), Eli Lilly (abemaciclib), and Novartis (ribociclib). Key patents related to composition of matter, methods of use, and formulations date back over a decade, framing the competitive intellectual property environment.
Major Patent Families and Competitive Landscape:
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Novartis (Palbociclib):
- The earliest patent (WO2007/139842) covers the compound itself, with subsequent patents covering methods of treatment, formulations, and dosing regimens [1].
- CA2821174 resides within this family, focusing on particular therapeutic applications.
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Eli Lilly (Abemaciclib):
- Patents focus on formulations and specific dosing schedules, including US and WO patents [2].
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Novartis (Ribociclib):
- Patent families similarly cover compositions, methods, and combinations with other therapies.
Patent Expiry Timeline:
- Composition patents for these molecules generally expire around 2025–2030, depending on jurisdictions and patent term adjustments.
- Use and method patents like CA2821174 provide additional exclusivity, potentially extending market control into the late 2020s or early 2030s.
Key Patent Citations and Related Applications:
CA2821174 is internationally linked through PCT applications and national filings, referencing prior patents focusing on chemical synthesis, pharmacokinetics, and treatment methods. The patent landscape reveals a robust network of overlapping protections, emphasizing method-based patents to fortify market position.
Innovative Features and Patentability
CA2821174 emphasizes novel dosing regimens and combination therapy protocols, which are patentable because:
- Dosing schedules can be patentable if they demonstrate unexpected efficacy or reduced toxicity.
- Combination therapies may be patentable if synergistic effects are demonstrated.
The patent's claims are adequately supported by experimental data showing improved efficacy in specific dosage regimes, aligning with requirements for patentability of method claims.
Legal and Commercial Implications
- This patent augments Novartis’s existing patent estate by covering specific therapeutic methods, potentially blocking generics from entering with similar treatment protocols.
- The patent may influence pricing strategies, reimbursement negotiations, and licensing arrangements.
- Infringement risks exist for competitors using similar dosing regimens or treatment combinations, especially if they target HR+/HER2- breast cancer with approved CDK4/6 inhibitors.
Conclusion and Industry Outlook
Canadian patent CA2821174 embodies a strategic combination of targeted cancer therapy, dosing optimization, and combination protocols. Its scope, confined to methodology for administering approved CDK4/6 inhibitors, aligns with common strategies in pharmaceutical patenting—extending exclusivity while avoiding patent blockades on composition of matter.
The existing patent landscape surrounding CDK4/6 inhibitors is densely populated with broad composition and specific use patents. CA2821174 secures additional protection around application-specific claims that could influence clinical practice, generic entry, and market exclusivity until approximately 2030.
Key Takeaways
- Scope focuses on specific treatment methods involving CDK4/6 inhibitors, notably dosing schedules and combination therapies within Canadian law.
- Patent claims are strategically narrow but impactful, seeking to block generic use in targeted treatment regimens.
- The patent landscape is highly competitive and mature, with overlapping rights from major originator companies, but method-based patents remain crucial for extending market exclusivity.
- Legal risks for competitors primarily involve infringing on dosing regimens or combination therapies.
- Practitioners should monitor pending and granted patents for emerging claims, especially as expiry dates approach, to inform strategic licensing or R&D decisions.
FAQs
1. What is the primary legal protection offered by patent CA2821174?
It protects specific therapeutic methods for administering CDK4/6 inhibitors in cancer treatment, focusing on dosing and combination protocols, thereby preventing others from using similar treatment regimens during the patent’s term.
2. How does CA2821174 fit within the broader patent landscape for CDK4/6 inhibitors?
It complements existing composition patents by targeting method and treatment protocols, thus enhancing exclusivity beyond the chemical entities themselves, which are often protected by core composition patents.
3. Are the claims in CA2821174 broad enough to cover all uses of CDK4/6 inhibitors?
No, the claims are specific to certain dosing schedules and therapeutic combinations, so they do not cover all possible uses or formulations outside the defined scope.
4. When do patents on the chemical compounds like palbociclib typically expire?
Core patents for compounds like palbociclib are generally set to expire between 2025 and 2030, with patent term extensions possibly delaying this slightly.
5. What should generic manufacturers consider regarding this patent?
They need to evaluate whether their proposed treatment methods infringe the claims—particularly dosing or combination strategies—or if first-in-class patents prevent marketing with similar protocols until expiry.
References
[1] WO2007139842 – Patent application relating to palbociclib composition and synthesis.
[2] US20170235159 – Eli Lilly’s patent describing abemaciclib formulations and methods.
[3] Canadian Patent CA2821174 – Full patent documentation.
Disclaimer: This analysis is for informational purposes and does not constitute legal advice. For strategic patent considerations, consult a qualified patent attorney.
