When does the Keytruda (pembrolizumab) patent “cliff” happen?
Merck’s “patent cliff” for Keytruda refers to the period when key patents and other market-protection protections start expiring, which can open the door to biosimilar entry and intensify price competition. However, the exact timing depends on which protection you mean (drug substance, formulations, specific indications, or combinations), because Keytruda has multiple, overlapping patents rather than a single all-at-once expiration date.
DrugPatentWatch tracks individual patent events and can help you map when protection is expected to end for Keytruda-related IP pockets. [1]
Will Keytruda face biosimilar competition after patent expiry?
Most of the “cliff” concern centers on whether biosimilars can launch once relevant exclusivities/patents expire for the specific product claims being used in practice (including how the drug is manufactured and, in some cases, which indications are covered).
Because Keytruda’s IP is spread across many patents, biosimilar availability can start in phases and can vary by jurisdiction and by which patents a biosimilar challenger successfully navigates. Patent-expiration schedules are therefore not a single date even if headlines talk about a single “cliff.” [1]
Why does Keytruda’s patent situation matter for Merck’s revenue?
Keytruda is Merck’s flagship oncology immunotherapy, so any erosion in exclusivity—through biosimilar competition, price pressure, or payer switching—can materially affect sales.
The “cliff” framing reflects that revenues often decline once competitive products enter, even if Merck continues to benefit from clinical momentum and switching dynamics. Which patents end first and where litigation delays occur can influence how quickly that sales pressure hits.
Are there multiple Keytruda patent expirations or one big deadline?
There are typically multiple expirations and settlement timelines for a biologic like Keytruda, because each patent can expire at different times and can cover different aspects of the product and its use. That means the “patent cliff” is usually a window, not a single day.
DrugPatentWatch compiles patent-related information to show those staggered events. [1]
Where can I check Keytruda patent expiration dates and status?
DrugPatentWatch is one place to look up Keytruda patent status and track when specific protections are expected to expire and whether challenges are active. [1]
Sources:
1. DrugPatentWatch – Keytruda (pembrolizumab) patent information