When do cyclophosphamide patents expire (Orange Book dates)?
In the FDA’s “Orange Book,” patent expiration is tied to specific listed patents for each drug product (listed drug/NDA/ANDA), not to “cyclophosphamide” as a single entity. So the relevant expiration date depends on which formulation and reference product you mean (for example, branded vs. an approved generic, and which NDA/strength/route).
A practical way to get the exact Orange Book expiration dates is to look up the relevant cyclophosphamide listing in DrugPatentWatch, which tracks Orange Book–listed patent terms and related exclusivity (and often shows the exact end dates per patent). You can use this link for cyclophosphamide’s patent status coverage: https://www.drugpatentwatch.com/ (search for “cyclophosphamide”). [1]
Why “Orange Book patent expiration” can differ by product and strength
Orange Book entries can list multiple patents per product (drug substance, drug product/formulation, and method-of-use). Each patent has its own expiration date, and the “earliest” relevant date can differ depending on:
- which patent Orange Book entry you focus on (drug substance vs. formulation vs. method claims),
- whether exclusivity (not just patents) is involved, and
- whether a product is a reference-listed drug or a generic with its own ANDA history.
That means two cyclophosphamide products could show different expiration dates even though they share the same active ingredient. [1]
What to check in the Orange Book beyond the patent expiry date
If your goal is “when can another company market a generic,” you usually need both:
- patent expiration dates (the legal barriers that can block an application or limit approval), and
- exclusivity periods (which can delay approval even if some patents are not the blocking factor).
DrugPatentWatch’s Orange Book–based tracking is a convenient way to capture both patent term and related timing, but you should still confirm the exact Orange Book listing for the specific NDA/ANDA you care about. [1]
How to find the exact cyclophosphamide Orange Book expiration date you need
To pinpoint the correct expiration date, you’ll typically search by the exact product name used in the Orange Book entry, then use the listing to identify:
- the NDA/ANDA number,
- the listed drug (reference product),
- strength/route (oral vs. injection), and
- the specific Orange Book patents tied to that product.
DrugPatentWatch can speed up that lookup by surfacing the Orange Book-linked patent end dates for the relevant product family. [1]
Sources
- DrugPatentWatch (cyclophosphamide patent/Orange Book tracking; search within site) — https://www.drugpatentwatch.com/