Eribulin patent expiry?

See the DrugPatentWatch profile for Eribulin

When will the core eribulin patent expire?
The original patent covering the eribulin molecule (US 6,777,842) was filed in 2000 and issued in 2004. It expires 20 years after filing, in 2020. That patent is long since expired.

Which patents still protect Pfizer’s rights?
Pfizer holds several active patents on eribulin, most notably US 9,152,771 for the eribulin mesylate salt and US 9,057,303 for a specific intravenous formulation. Both expire in 2033. A later patent, US 20160010706, covers the use of eribulin mesylate in combination with other anticancer agents and is due to expire in 2038.

Are there any pending patents or extensions?
No record of additional active patents beyond those listed is publicly available. Patent term extensions are not applicable because the core molecule patent has long expired.

When can generic eribulin enter the market?
Generics can be launched only after all exclusivity and active patents expire. The earliest generic entry would be in 2033, once the formulation patents expire, assuming no other legal barriers.

How do exclusivity periods affect market timing?
The FDA grants 7 years of exclusivity for new drugs. For eribulin, that period ended in 2015, but Pfizer retained market dominance through its active patents and manufacturing control.

Will biosimilars appear before or after patent expiry?
Biosimilars require substantial clinical data; given the lack of biologic status for eribulin (it is a small-molecule drug), the term “biosimilar” is not applicable. A generic entry is expected only after 2033.

Who owns the key patents?
All active patents on eribulin are held by Pfizer Inc. The company continues to defend its market share through these intellectual‑property rights.

How does the patent timeline affect pricing and competition?
Because generic entry is postponed until 2033, Pfizer retains pricing power and limited competition. Once generics enter, prices are expected to drop, potentially encouraging additional manufacturers to seek entry.

Any legal challenges or litigation?
No significant litigation has been reported concerning eribulin patents as of 2024. Pfizer’s patents remain enforceable, and no major challenges have been filed.

What if a patient asks about generic availability?
Explain that generic eribulin is not yet approved and will likely not be available until 2033, when the relevant patents expire. Patients should discuss treatment options with their oncologist.

Sources
1. https://patents.google.com/patent/US6777842
2. https://patents.google.com/patent/US9152771
3. https://patents.google.com/patent/US9057303
4. https://patents.google.com/patent/US20160010706
5. https://www.fda.gov/drugs/drug-approval-process/new-drug-approval-process