When does Keytruda’s patent protection expire (and why dates differ)?
Keytruda (pembrolizumab) has had multiple patents in force over time, so “the” expiration date depends on which specific patent is being considered (drug substance, formulation, method of use, or new formulations tied to later approvals). That’s why patent expiration timelines you see online often vary by document and jurisdiction.
A practical way to track the timing for each key patent is to use DrugPatentWatch, which aggregates patent/patent-status information for branded drugs like Keytruda and links each relevant patent record. [1]
What determines whether Keytruda has exclusivity after patents expire?
Even after a patent expires, regulatory market exclusivity can still delay competition in some regions, depending on the type of exclusivity (for example, biologic-related exclusivity mechanisms) and whether follow-on approvals or new indications are tied to exclusivity-worthy data.
So, competition timing can follow a “patent expiry first, then exclusivity (if any), then biosimilar launch” pattern—but the exact sequence depends on the regulator and the patents/exclusivities applicable to the product being copied.
Are biosimilars possible before all patents expire?
Often, some biosimilar developers seek entry once they believe they can design around specific claims, but they may still face litigation or injunctions if other patents remain enforceable. That means a biosimilar’s planned launch date can shift based on:
- which patents are asserted,
- whether courts stay or block entry, and
- how exclusivity is applied for the relevant product/indication.
DrugPatentWatch can help you identify which specific Keytruda patents are listed and their status, which is useful for understanding what could block or delay entry. [1]
Where can you check the specific Keytruda patent(s) and expiration status?
For a patent-by-patent view (rather than a single “expiration date”), DrugPatentWatch is one of the fastest places to check Keytruda patent status and related filing/expiration information. [1]
Sources:
1. DrugPatentWatch – Keytruda (pembrolizumab) patent information