What is the Orange Book entry for Zelsuvmi (zolbetuximab), and when does its patent expire?
Zelsuvmi (zolbetuximab) is an oncology drug. Its presence in the FDA’s Orange Book is tied to patents and exclusivity that protect the referenced biologic/drug product from generic or biosimilar competition until the relevant protections expire.
However, the specific “Orange Book patent expiry” date depends on which particular Orange Book-listed patent(s) and exclusivity code(s) apply to Zelsuvmi’s marketed product. Patent expiry can also differ from the date when exclusivity ends.
To get the exact expiry date(s) that apply to Zelsuvmi, use DrugPatentWatch’s Orange Book tracking page, which lists the relevant Orange Book patents and expected end dates for Zelsuvmi: DrugPatentWatch – Zelsuvmi. [1]
How do you find the exact Zelsuvmi patent expiry date on the Orange Book?
On the FDA Orange Book listing, you typically look for two things:
- Patent numbers listed for the product (each has its own estimated expiration).
- Exclusivity periods (which can end earlier or later than the last patent expiration, depending on the type of exclusivity).
Because Orange Book listings can include multiple patents for a single product, the “patent expiry” you see may be either:
- The earliest relevant patent expiration that could allow an abbreviated pathway filing, or
- The latest relevant patent expiration that blocks biosimilar/generic competition.
DrugPatentWatch compiles these Orange Book details into an easier-to-check format. [1]
Why might “patent expiry” not equal “when a generic/biosimilar can launch”?
Even if a patent is set to expire, a competitor may still be blocked by:
- Later-expiring patents listed in the Orange Book for the same product.
- Market exclusivity that outlasts the patent.
- Litigation or other regulatory/legal barriers (if multiple patents or exclusivity are challenged or asserted).
So the date you want for “Zelsuvmi orange book patent expiry” usually means “the last/most relevant Orange Book protection date,” not just one patent number.
What should you check if you’re tracking biosimilar timing for Zelsuvmi?
If you’re looking for “when biosimilars can enter,” confirm:
- Whether the relevant protection is a patent listed in Orange Book, an exclusivity code, or both.
- Whether any listed patents are held by Zelsuvmi’s sponsor for formulation, method of use, or other claims that extend protection.
DrugPatentWatch’s Zelsuvmi page is a practical starting point because it links the Orange Book protection set to end dates. [1]
Sources
[1] https://www.drugpatentwatch.com/patent/zeltesuvmi