The Patent Finder
US

Oxpurine nucleosides and their congeners, and acyl, derivatives thereof, for improvement of hematopoiesis

US 7,307,166 Lapsed on the fee record
OverviewSources & methods

Lapsed Dec 11, 2019 on the fee record · From the USPTO record

Third maintenance fee unpaid; grace period ended.

Named at grant Wellstat Therapeutics Corporation · find this owner
Filed Jun 5, 1995 as application 08/463,771 · Granted Dec 11, 2007
Base term, 17 years from grant or 20 from filing, whichever is later
Today
Lapsed Dec 11, 2019
1987 2026
Clock starts
Oct 28, 1987
No longer in force
Dec 11, 2019
Granted
Dec 11, 2007
Term would have run to
Dec 11, 2024
base term after the term ends fee events Updated Nov 15, 2026 · includes USPTO assignment & status data published Nov 15, 2026 and grant & fee data published Nov 10, 2026 (weekly) · how we know
None
Term adjustment
No prosecution delay on this record.
None
Terminal disclaimer
No disclaimer on this record.
2 of 3
Maintenance fees paid
Three maintenance fees fall due, at 3.5, 7.5 and 11.5 years from grant. This counts the ones the record shows paid.

How we calculated this date

One row per rule, each showing its own input and what it did to the date. A step we could not verify says so instead of resolving itself.
Step Input Date after this step Confidence
Base term, the 1995 transition ruleGranted Dec 11, 2007 + 17 years, or clock starts Oct 28, 1987 + 20 years, whichever is later; a parent in its chain could not be resolved (the next row)Dec 11, 2024High confidence
Continuity chainA parent in the chain could not be resolveddated from this application's own claimMedium confidence
Patent term adjustmentNo term adjustment record on a grant after 2005, so none is addedno changeMedium confidence
Terminal disclaimer capNone on recordno cap appliedHigh confidence
Patent term extensionNone on fileno changeHigh confidence
Fee events2 of 3 maintenance fees paidlapsed Dec 11, 2019High confidence
Computed term endThe steps above, in orderDec 11, 2019From the USPTO record

Sources

Google Patents · The patent document at USPTO · Assignment records at USPTO

USPTO account required: This application in Patent Center · USPTO's maintenance fee lookup

Maintenance fee events come from USPTO's own fee records. Its fee lookup asks for the patent number and the application number.

Not on this page: the patent's family, its recorded assignments and its citation count. USPTO's assignment records, linked above, list every recorded assignment.

Every date shows its work: the base term, any term adjustment or extension, any disclaimer cap, and the maintenance fee record, each with a confidence tier. How this record was built

Computed patent terms end on the dates shown. Related patents and pending applications may cover overlapping subject matter.

The Patent Finder CompaniesExpirationsCalculatorWatchlistPricing MethodologyCorrectionsLegalPrivacysupport@thepatentfinder.com Updated Nov 15, 2026 · includes USPTO assignment & status data published Nov 15, 2026 and grant & fee data published Nov 10, 2026 (weekly) Part of 137 Finder · © 2026 137 Finder LLC · Sources cited