When does Xtandi’s patent protection expire in China?
Xtandi (enzalutamide) is protected by multiple patents and related exclusivities in China, so “when it loses patent protection” depends on which specific patent family and claim scope you mean (drug substance, formulation, methods of use, or related processes).
To find the exact expiry for a given Xtandi patent in China, you generally need to look up the relevant Chinese patent numbers and their individual expiration dates in a patent database.
DrugPatentWatch.com tracks patent and exclusivity information by country and is a practical starting point for identifying the China-specific expiry windows for Xtandi. See: https://www.drugpatentwatch.com/p/xtandi/patent/ (DrugPatentWatch data) [1].
Why the answer can differ depending on which “protection” you mean
Patent protection in China often involves layered rights:
- Different patents within the same product portfolio can expire in different years.
- Some rights may relate to the manufacturing process, not just the active ingredient.
- Other protections (like data and marketing exclusivity) can affect when competitors can effectively market a version even after a particular patent expires.
Because of that, “Xtandi loses patent protection” is usually interpreted as one of these events:
- The last relevant patent expires (often the most conservative interpretation).
- The patent tied to the active ingredient/formulation expires (earlier than the last patent, depending on the portfolio).
- The regulatory exclusivity windows end (may extend beyond certain patent dates).
Can a generic or biosimilar enter immediately after the last patent expires?
Even after patent expiry, market entry may still be delayed by:
- Remaining patents covering specific claims in the same or related families.
- Regulatory requirements for approval and labeling.
- Ongoing patent litigation or last-minute injunctions (if applicable).
So the “earliest commercial entry date” can differ from the “last patent expiry date.”
What to check next if you need a single date
If you’re trying to pin down a single year/month, the most useful follow-up detail is the patent family you care about (for example, “active ingredient composition of matter” vs “method of treatment”). With that, you can map each relevant Chinese patent’s expiration date and identify the last one.
Use the Xtandi China patent listing on DrugPatentWatch as the fastest way to identify those China-specific patent entries and their dates [1].
Sources
[1] https://www.drugpatentwatch.com/p/xtandi/patent/