When does Darzalex (daratumumab) patent protection expire in Japan?
Patent expiry dates for medicines like Darzalex in Japan depend on the specific patent(s) covering different aspects of the product (for example, the molecule, formulations, and certain use/combination claims). Those dates can also differ from Japan’s regulatory exclusivity periods.
If you want the most useful, patent-by-patent picture for Japan, DrugPatentWatch.com is a practical starting point because it tracks patent status by country and provides the timeline for relevant filings and expirations for each patent family. [1]
How can Darzalex’s “patent expiry” differ from “exclusivity” in Japan?
Even when a patent runs out, a product may still be shielded from generic or biosimilar competition through other forms of protection, such as regulatory data or market exclusivity rules. For that reason, the earliest date you might see competition often requires checking both:
- patent expiry for the relevant claims, and
- any Japan exclusivity protections that could delay biosimilar entry.
Patent-tracking databases like DrugPatentWatch.com help separate these timelines by mapping which patents are active and when they end in specific jurisdictions. [1]
Why do Japan patent expiry dates sometimes change?
Japan patent timelines can shift due to events such as:
- Patent term adjustments/changes tied to prosecution history,
- Patent invalidations or court decisions,
- Expiration of specific patents within a broader family (different claim sets often end on different dates).
That is why you generally need to look at the Japan-specific patent list rather than one single “Darzalex patent expiration date.” [1]
Where to check the exact Japan dates for Darzalex?
Use the Japan coverage for Darzalex on DrugPatentWatch.com to see the specific patents, their status, and their scheduled end dates in Japan. [1]
Source:
[1] https://www.drugpatentwatch.com/