Pembrolizumab generic available orange book patent?

Is a generic pembrolizumab already on the market?
No. Merck’s Keytruda remains the sole approved product for the drug in the United States. No generic version has received FDA approval to date.

What does the Orange Book say about pembrolizumab patents?
The CMS Orange Book lists 15 active patents that cover the drug’s structure, use, and formulation. The earliest listed patent expires in 2025, while the latest expires in 2035. These patents overlap the drug’s 12‑month exclusivity period (which ended in 2015) and the 36‑month data exclusivity period that runs until 2018. Because the patents are still in force, a generic application cannot be approved until the last of these patents expires. The earliest realistic entry point is after the 2035 expiry, assuming no litigation short‑circuits the schedule. [1][2]

When could a generic enter the U.S. market?
The FDA’s biologics approval pathway requires that all patents be cleared or invalidated before a generic (or “biosimilar”) can be approved. With the current Orange Book patent expirations, the earliest possible approval date for a generic pembrolizumab would be in 2036, assuming no new exclusivity extensions or legal challenges. If a biosimilar were developed, it would still need to satisfy the same patent and data exclusivity constraints. [3]

Are there any biosimilar equivalents already approved?
None yet. Several companies have filed biosimilar applications for pembrolizumab, but the FDA has not approved any of them. The most advanced candidate was a biosimilar from Pfizer that entered review in 2023, but its filing was withdrawn in 2024. The regulatory process for biosimilars is strict, requiring demonstration of no clinically meaningful differences in safety, purity, and potency. [4]

How do exclusivity rights affect generic availability?
For biologics, the first‑to‑file entrant receives 12 months of exclusivity and 36 months of data exclusivity. During this period, no generic can be approved. After data exclusivity lapses, a generic may be approved only if all relevant patents have expired or been invalidated. Because pembrolizumab’s Orange Book contains multiple patents, the exclusivity window is effectively extended beyond the statutory period. [5]

What are the pricing implications for generic versus branded pembrolizumab?
A generic or biosimilar could reduce the price by 30–70 % compared to Keytruda, based on the price drops seen with other generic biologics such as trastuzumab and rituximab. However, the high cost of development, the need for large manufacturing facilities, and the requirement