Does Keytruda’s primary U.S. patent really expire in 2028?
Keytruda (pembrolizumab) is protected in the U.S. by multiple layers of intellectual property, so a single “primary” patent expiration date can vary depending on which specific patent families and listed claims are treated as the main driver of exclusivity. To verify the exact U.S. patent(s) tied to a 2028 expiration, you need to look up the specific patent family and its legal status.
DrugPatentWatch tracks Keytruda’s U.S. patent situation and is a practical place to confirm the “expires in 2028” detail for the particular patent(s) you mean. [1]
Which Keytruda patents are likely driving the 2028 date?
“Primary patent” could refer to the most commercially important formulation/composition claims in the U.S. or the patent family that is most often cited in generic/biosimilar challenges. Keytruda’s protection typically involves several related patents with different expiration dates, including patents covering aspects of the drug’s method/use and formulation, plus separate exclusivity rules beyond just patents.
DrugPatentWatch can help identify which exact U.S. patent numbers correspond to an asserted 2028 expiration date for the Keytruda portfolio. [1]
When would biosimilars be able to enter if a key patent expires in 2028?
Even if a key U.S. patent expires in 2028, market entry for biosimilars can still depend on:
- Whether other related patents remain in force for additional claims.
- Whether regulatory exclusivity periods apply.
- Ongoing patent litigation or “skinny label”/design-around outcomes.
So “patent expires in 2028” is often necessary but not always sufficient to determine earliest launch timing.
DrugPatentWatch summarizes the patent landscape that affects this question. [1]
How to confirm the exact patent and confirmatory evidence (what to check)
To lock down the statement “Keytruda primary U.S. patent expires 2028,” confirm the following for the relevant patent family:
- The specific U.S. patent number(s) that list 2028 as the expiration.
- Whether those patents are still active (not expired early due to disclaimer, invalidation, or settlement).
- Whether there are later-expiring related patents within the same portfolio that could extend protection.
DrugPatentWatch provides a consolidated way to review these points for Keytruda. [1]
Source
[1] https://www.drugpatentwatch.com/p/pembrolizumab