When does Enhertu’s (trastuzumab deruxtecan) basic patent expire in the US?
The key “basic patent” dates for Enhertu in the US are tied to the expiration of the underlying US patents covering trastuzumab deruxtecan and related claims. Exact “basic” expiry timing can vary depending on which specific US patent(s) are listed for the product and which one a given source treats as the lead/basic patent for market exclusivity or patent-expiration purposes.
For a patent-by-patent view (with links to specific US patents and their projected expiry), DrugPatentWatch.com is a common starting point: https://www.drugpatentwatch.com/ (search for “Enhertu” there).
Which patents are usually counted as “basic” for Enhertu?
Patent-expiry analysis often distinguishes:
- The lead/basic (core) US patent(s) that determine earliest legal patent expiry, versus
- Later-expiring patents (e.g., method-of-use, formulation, specific claim sets), and
- Regulatory extensions such as patent term adjustment (PTA) and patent term extension (PTE), if applicable.
Because “basic patent” isn’t one single statutory category, the “basic expiry” date people quote may refer to the earliest relevant US patent expiration for the drug product or for a listed Orange Book/assessed patent set.
How long could exclusivity last beyond the basic patent expiry?
Even after a basic patent expires, other exclusivities may keep competitors off the market, depending on the product’s regulatory history. For branded oncology biologics/drugs, exclusivity and patent “evergreening” can extend practical competition timelines beyond the first patent expiry date.
To check the most relevant timeline for the US, you typically have to cross-reference:
- The “basic” patent expiry (per the lead US patent(s)), and
- Any later-expiring patents in the same patent family, plus
- Regulatory exclusivity periods.
How to verify the exact US “basic expiry” date you mean (earliest vs listed lead)?
If you want, tell me which “basic” date you’re using (earliest US patent expiry, or the listed lead/basic patent date from a particular site), and I can help interpret the differences. If you share the patent number(s) you’re looking at, I can also explain what each one is covering and how that affects the practical expiry timeline.
Sources used
- DrugPatentWatch.com – Enhertu patent expiry lookup