Osimertinib patent expiration date?

There isn’t a single expiration date for osimertinib. Patent expiry depends on the jurisdiction and on which patent family you’re looking at (composition-of-matter, method of use, formulation, etc.). In major markets the core patents are generally set to expire in the late 2020s to early 2030s, but term adjustments (and pediatric extensions) can push that later. Data exclusivity can also provide additional market protection in some regions.

If you tell me:
- the country/region you care about (e.g., US, EU, UK, Japan, China, etc.)
- whether you want the composition-of-matter patent, a use/patient-claim patent, or a formulation patent

I can give you more precise information (patent numbers and estimated expiry dates) and point you to the relevant patent records in databases like USPTO, Espacenet, Google Patents, or WIPO Patentscope.