Overview of Patent BRPI0613233
Brazilian patent BRPI0613233, filed on June 5, 2006, protects a synthetic process for producing (S)-(+)-10,11-dihydro-10-hydroxy-5H-dibenzo[b,f]azepine-5-carboxamide, the active ingredient in APTIOM® (eslicarbazepine acetate)[5][6]. Owned by Sumitomo Pharma, this patent is part of a global family spanning 26 countries, with 100 family members, and has faced litigation in multiple jurisdictions[5]. The patent’s claims focus on process chemistry—specifically, steps to synthesize enantiomerically pure forms of the compound—which distinguishes it from composition-of-matter patents[5][7].
Scope of Protection and Claim Analysis
Key Claims and Technical Specificity
The patent’s title and legal descriptions indicate that its claims center on:
- Stereoselective synthesis of the (S)-(+)-enantiomer using chiral resolution techniques[5][6].
- Intermediate compounds, such as (S)-(-)-10-acetoxy-10,11-dihydro-5H-dibenzo[b,f]azepine-5-carboxamide, critical to the reaction pathway[5].
- Crystallization methods to achieve high purity, which are essential for pharmaceutical-grade production[7].
Under Brazilian law, process patents are interpreted narrowly, covering only the explicit steps described in the claims[7][10]. For example, if a competitor uses an alternative crystallization solvent or skips a claimed intermediate, they may avoid infringement unless the steps are deemed "equivalent" under the doctrine of equivalents[7].
Regulatory and Legal Constraints
- ANVISA Prior Consent: As a pharmaceutical patent, BRPI0613233 required prior approval from Brazil’s health regulator (ANVISA) under Article 229-C of the Brazilian IP Law[8][14]. ANVISA’s review focused on health risks rather than patentability, but delays in this process contributed to the patent’s prolonged prosecution[14].
- Term Extension: Due to Brazil’s backlog-driven term extension rule (Article 40 Sole Paragraph), the patent’s 20-year term was extended beyond the standard period because examination took over 10 years[14][15]. This extension is critical for maintaining market exclusivity until at least 2026[5].
Patent Landscape and Competitive Threats
Generic Challenges and Litigation
- Paragraph IV Challenges: One tentatively approved generic has filed a Paragraph IV certification, arguing non-infringement or invalidity[5]. In Brazil, such challenges often hinge on whether the generic’s process avoids the patented steps or uses non-equivalent alternatives[7].
- Global Litigation: The patent family has faced validity disputes in the U.S. and Europe, particularly over obviousness and lack of inventive step[5]. Outcomes in these jurisdictions may influence Brazilian proceedings under the principle of comity[7].
Market Impact and Strategic Considerations
- API Suppliers: Two suppliers are listed for eslicarbazepine acetate, but their methods must avoid the patented process to avoid contributory infringement[5][7].
- Secondary Patents: Sumitomo has filed follow-up patents covering formulations and dosage regimens, creating a patent thicket around APTIOM®[5][15].
- Post-Expiry Landscape: Post-2026, generics may enter, but regulatory exclusivity for clinical data could delay competition until 2029 under Brazil’s 10-year data protection rule[14].
Comparative Analysis of Claim Strategies
Process vs. Composition Claims
Unlike composition patents, which protect the compound itself, BRPI0613233’s process claims are more vulnerable to design-around strategies. For instance, a generic manufacturer could:
- Use a different chiral catalyst to synthesize the enantiomer[10].
- Modify reaction temperatures or solvents to alter crystallization dynamics[12].
However, if such changes are deemed functionally equivalent, infringement may still occur[7].
Prosecution History and Amendments
During examination, the applicant likely narrowed claims to overcome prior art, such as:
- Restricting the claims to specific acetate derivatives to avoid overlap with older patents[6][11].
- Adding temperature ranges (e.g., 20–25°C) to distinguish from broader methods[12].
Economic and Policy Implications
Backlog-Driven Term Extensions
Brazil’s patent office (INPI) has a backlog of ~150,000 applications, with pharmaceutical patents averaging 7 years from examination request to grant[14][15]. This delays generic entry but undermines predictability for innovators. Recent reforms, like the 2019 Backlog Reduction Plan, aim to cut delays but have yet to significantly impact older cases like BRPI0613233[15].
Impact on Public Health
Extended exclusivity for APTIOM® limits access to affordable epilepsy treatments. A 2021 study estimated that delaying generics could cost Brazil’s public health system (SUS) R$3.9 billion over five years for just nine drugs[14].
Conclusion
BRPI0613233 exemplifies the strategic use of process patents in Brazil’s complex pharmaceutical landscape. While its narrow claims face design-around risks, term extensions and secondary patents prolong market exclusivity. For generics, success hinges on innovative process engineering and leveraging Brazil’s evolving patent jurisprudence. Policymakers must balance innovation incentives with access imperatives by addressing systemic delays and refining term extension rules.
Key Takeaways
- BRPI0613233 protects a stereoselective synthesis process for eslicarbazepine acetate, with claims vulnerable to non-literal infringement.
- Term extensions due to INPI’s backlog add ~3.5 years of exclusivity, delaying generics until 2026.
- Litigation outcomes in the U.S. and Europe may influence Brazilian courts under comity principles.
- Brazil’s patent backlog disproportionately benefits originators, raising public health costs.
FAQs
1. How does Brazil’s patent term extension rule work?
Patents granted after a 10-year prosecution delay receive a term of 10 years from grant, overriding the standard 20-year term[14][15].
2. Can generics bypass process patents easily?
Yes, through design-arounds, but equivalents may still infringe if the modified process achieves the same result[7][12].
3. What role does ANVISA play in patent grants?
ANVISA reviews pharmaceutical patents for health risks but does not assess patentability, though delays here contribute to term extensions[8][14].
4. Are there data exclusivity protections in Brazil?
Yes, 10 years of data exclusivity for clinical trials, independent of patent status[14].
5. How significant is Brazil’s patent backlog?
As of 2025, ~80,000 applications await examination, with pharmaceuticals averaging 7-year delays[15].
“Brazil’s patent term extensions due to backlog create an unbalanced system, favoring patentees at the expense of public health.” — Scientific Study on Pharmaceutical Patents in Brazil[14]
References
- https://www.uspto.gov/patents/search
- https://www.uspto.gov/patents/search/patent-public-search
- https://patseer.com
- https://curity.io/resources/learn/scopes-vs-claims/
- https://www.drugpatentwatch.com/p/expiring-drug-patents-generic-entry/Brazil
- https://patents.google.com/patent/EP1917023A4/ja
- https://www.montaury.com.br/en/scope-of-patent-protection-brazil
- https://pubmed.ncbi.nlm.nih.gov/27804784/
- https://www.uspto.gov/ip-policy/economic-research/research-datasets/patent-claims-research-dataset
- https://klarquist.com/patent-defenses/how-construed/
- https://www.ssrn.com/abstract=2117827
- https://wysebridge.com/what-is-the-difference-between-claim-broadening-and-claim-narrowing-during-patent-prosecution
- https://scholarship.law.upenn.edu/cgi/viewcontent.cgi?article=1202&context=penn_law_review
- https://www.scielo.br/j/csp/a/NvjWxCR3BghNTRgbxpLTwsb/
- https://www.lickslegal.com/brazilian-patent-statistics
- https://www.scielo.br/j/rgenf/a/4PjnTHmYRFqzskPqZbQjTGL/
- https://www.gov.br/inpi/en/services/patents/basic-guide/patent-search
- https://www.kasznarleonardos.com/en/brpto-releases-study-on-5g-patent-landscape-in-brazil-and-worldwide/
Last updated: 2025-04-19
