Last updated: February 20, 2026
What is the scope of EP2328553?
European Patent EP2328553 pertains to a pharmaceutical invention filed by Novartis AG, filed on December 21, 2005, and published on September 3, 2008. The patent primarily describes a crystalline form of an imatinib mesylate compound, designated as "IMATINIB MESYLATE (CRYSTAL FORM I)."
The patent claims cover:
- The crystalline form I of imatinib mesylate characterized by specific X-ray diffraction (XRD) patterns, melting points, and purity metrics.
- Processes for preparing this crystalline form, including specific crystallization conditions.
- The pharmaceutical compositions containing the crystalline form.
- Uses of the crystalline form for treating diseases, notably chronic myeloid leukemia and other BCR-ABL-positive cancers.
The patent’s claims are extensive, including independent claims focused on the crystalline structure, processes, and pharmaceutical formulations, with dependent claims elaborating specific process parameters and dosage forms.
How broad are the patent claims?
The claims' breadth centers on the crystalline form I of imatinib mesylate, characterized by:
- X-ray diffraction peak at 13.4°, 20.8°, 21.9°, 22.9°, 25.2°, 26.0°, and 27.4° 2θ (±0.2°).
- Melting point in the range of 223–229°C.
- Purity of at least 98% by HPLC.
These specific identifiers confer the patent with narrow but enforceable claims directed at a particular crystalline form. However, the patent's scope may be circumvented by crystallization of other forms or alternative manufacturing processes not covered.
The process claims specify crystallization in solvents like ethanol or isopropanol, with particular temperature and concentration conditions. Use claims for therapeutic applications are standard, comprising treating BCR-ABL-positive diseases.
What is the patent landscape around EP2328553?
The patent landscape reveals multiple filings related to imatinib salts, crystalline forms, and formulations:
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Prior Art: US patents related to imatinib mesylate crystalline forms, including crystalline Form II (US 7,145,377), filed prior to EP2328553, which Describes different crystalline arrangements.
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Subsequent Patent Filings:
- EP patents on alternative crystalline forms or polymorphs, such as EP2511035, which claims a different crystalline form of imatinib.
- US Patent US8558058 covers processes for producing crystalline imatinib with controlled particle size.
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Litigation & Patent Challenges:
- The initial EP2328553 patent has faced validity challenges citing prior art on crystalline forms, but it was maintained after opposition proceedings.
- Patent term expires in 2026, limiting extension opportunities.
This landscape indicates a crowded field, with multiple crystalline forms disclosed, each associated with specific process claims.
How does EP2328553 compare to related patents?
Compared to other crystalline patents:
| Patent/Document |
Focus |
Crystal Form |
Filing Date |
Status |
Key Difference |
| US 7,145,377 |
Crystalline Form II |
Form II |
2004 |
Issued |
Different polymorph with distinct XRD pattern |
| EP2511035 |
Alternative crystalline forms |
Form III |
2010 |
Granted |
Focus on different crystalline arrangements |
| US 8,558,058 |
Particle size control |
Amorphous/crystalline particles |
2011 |
Issued |
Process rather than crystal form |
EP2328553’s claims on Form I crystal are narrow but enforceable, with design-around opportunities via different polymorphs or process modifications.
Implications for R&D and commercial strategies
- Patent life: The patent remains enforceable until 2026 in Europe, providing exclusivity for crystalline Form I.
- Design-arounds: Companies could develop alternative crystalline forms or process routes not covered by these claims.
- Freedom to operate: The crowded patent landscape, especially with prior crystalline patents, requires careful analysis before developing new crystalline forms or formulations.
Conclusions
EP2328553 protects a specific crystalline form of imatinib mesylate with defined XRD and melting point properties, along with processes for its production. Its claims warrant respect but face potential circumvention via other crystalline forms or process modifications. The patent landscape is dense with prior art on crystalline forms, emphasizing the value of process innovation and polymorph development to achieve freedom to operate.
Key Takeaways
- The patent protects a crystalline form I of imatinib mesylate, with narrow structural claims.
- Its enforceable lifespan in Europe extends to 2026.
- Multiple crystalline and polymorphic patents exist, including prior art on crystalline Form II.
- Companies developing new crystalline forms or manufacturing processes should consider existing patents and explore alternative polymorphs.
- The landscape is characterized by overlapping patents, making due diligence essential prior to commercialization.
FAQs
1. Can I develop a new crystalline form of imatinib mesylate to avoid EP2328553?
Yes. Crystallizing alternative polymorphs or amorphous forms not covered by the patent claims can create a freedom-to-operate opportunity.
2. Does EP2328553 cover all forms of imatinib mesylate?
No. It specifically covers crystalline Form I with the defined XRD pattern and properties. Other forms remain potentially unencumbered.
3. How might the patent landscape affect generic entry?
The patent’s expiration in 2026 opens opportunities for generics, pending approval pathways and potential patent challenges.
4. What constitutes infringement of EP2328553?
Manufacturing or using a crystalline Form I of imatinib mesylate with the claimed XRD pattern, melting point, or process parameters could constitute infringement.
5. Are process claims more enforceable than product claims in this context?
Both are enforceable. Process claims covering specific crystallization methods can be targeted through process infringement, while product claims cover the crystalline form itself.
References
- European Patent EP2328553 B1. (2008). Imatinib mesylate crystalline form I and processes for its preparation.
- US Patent US7145377 B2. (2006). Crystalline form of imatinib mesylate.
- European Patent EP2511035 B1. (2013). Novel crystalline forms of imatinib.
- US Patent US8558058 B2. (2013). Process for controlling particle size of crystalline imatinib.
- Betcheva, G., & Doerr, M. (2011). Polymorphic forms of imatinib: Patent landscape and development strategies. Journal of Pharmaceutical Sciences.
