Patent No. EP3501542 (titled "Esketamine For The Treatment Of Depression") was filed by Janssen Pharmaceutica on Dec 21, 2018. The application was issued on Jan 28, 2026.

Patent oppositions filed by competitors challenge the validity of a granted patent. These oppositions are typically based on claims of prior art, lack of novelty, or non-obviousness. They are a key part of the process for determining a patent's strength and enforceability.
| Company | Opposition Date | Representative |
|---|---|---|
| ELKINGTON AND FIFE | Oct 6, 2026 | ELKINGTON AND FIFE |
The dossier documents provide a comprehensive record of the patent's prosecution history - including filings, correspondence, and decisions made by patent offices - and are crucial for understanding the patent's legal journey and any challenges it may have faced during examination.
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