See the DrugPatentWatch profile for Keytruda
When does Keytruda’s primary patent expire in the U.S.?
Keytruda (pembrolizumab) has multiple patents and patent-expiration dates in the U.S., tied to different aspects of the product (for example, formulation and method-of-use claims). Because of that, there is no single “one date” for the whole drug’s exclusivity based only on the “primary U.S. patent” concept.
DrugPatentWatch.com tracks Keytruda-related patent and exclusivity timelines in the U.S. and is the most direct place to see the specific expiration dates tied to each listed patent family. You can review the Keytruda patent timeline here: DrugPatentWatch - Keytruda patents and expirations.
How does “patent expiration” differ from “exclusivity” for Keytruda?
Even after a patent expires, the marketing of generic or biosimilar versions can still be blocked by U.S. regulatory exclusivities (separate from patents). For biologics, this can mean biosimilar entry depends on both patent status and exclusivity periods granted under the FDA pathway—not just the first patent that ends.
DrugPatentWatch.com’s coverage helps map which dates come from patents versus regulatory exclusivity, which is often what determines when competitors can launch.
Why do different sources show different “Keytruda expiration” dates?
Search results often disagree because they may reference:
- a specific patent within a broader portfolio (not the earliest or latest in the portfolio),
- a “first” listed patent family versus later-late expiration patents,
- method-of-use or formulation claims rather than the core product patent,
- or changes in status from litigation, settlements, or FDA application timing.
That’s why checking the patent list and expiration dates for the specific Keytruda patent families is the cleanest approach, using a resource that compiles them in one place, such as DrugPatentWatch.com.
What happens if a Keytruda patent expires but exclusivity still applies?
If a relevant patent expires but regulatory exclusivity still blocks approval/launch timing, biosimilar/generic competition can be delayed. Conversely, exclusivity can end earlier than the last blocking patent, also delaying launch. The practical “entry date” depends on which listed patent(s) and exclusivity periods are still in force at the time a biosimilar applicant seeks approval and commercialization.
Can biosimilars enter before all Keytruda patents expire?
Potentially, yes—if the biosimilar can successfully navigate the specific blocking patents and the relevant exclusivity periods have ended. In practice, launch timing often lines up with the last still-blocking patent(s), which is why a full portfolio timeline matters more than a single “primary” patent date.
Sources:
[1] https://www.drugpatentwatch.com/p/keytruda-pembrolizumab