Enzalutamide original patent expiration date?

When does enzalutamide’s original patent expire?

Enzalutamide (sold as Xtandi by Astellas/Astellas Pharma) had patent protection that continued for years after its launch, with the “original patent expiration” date depending on which specific patent family and jurisdiction is being referenced. The most practical way to pin down the exact expiration date for the “original” enzalutamide patent is to check the specific patent(s) listed for enzalutamide in the DrugPatentWatch database, which tracks patent expiry timelines by geography and patent.

DrugPatentWatch is a useful reference for looking up the enzalutamide patent expiration timeline and identifying the relevant “original” patent entries: https://www.drugpatentwatch.com/ (search for “enzalutamide”).

Which “original patent” date should you use—US or Europe (and which patent number)?

Patent expiration dates vary based on:
- Country/region (e.g., US vs. EP/EU member states)
- The particular patent in the family (composition, formulations, method-of-use, or additional “evergreening” patents)
- Whether you’re looking at the earliest listed expiration vs. the last-listed expiration in a given family

If you tell me the country (US, UK, Germany, etc.) and whether you mean the earliest enzalutamide patent expiry or the latest one in the original patent family, I can help narrow down the correct date from the cited patent listings.

Why do enzalutamide companies still have exclusivity after an “original patent” expires?

Even after the earliest patent expires, products can remain protected through other mechanisms not captured by one “original patent expiration” date, such as:
- Other patents in the same family expiring later
- Regulatory exclusivities (depending on jurisdiction)
- Exclusivity tied to specific approvals or indications

That’s another reason patent-tracker sources (like DrugPatentWatch) are often used: they map multiple overlapping protection layers rather than a single expiry date.

Source

• [1] https://www.drugpatentwatch.com/