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Nucleoside Phosphoramidate Prodrugs

US 9,585,906 In force, term unresolved
OverviewFamilyAssignmentsSources & methods

Term ends no later than Mar 21, 2028 · Low confidence

In force on USPTO's status record and by its fee record. A terminal disclaimer on file may shorten this term, possibly to a date already past; its reference document is unresolved, so the date above is an upper bound and no earlier date is guessed.

Filed Mar 12, 2015 as application 14/656,546 · Granted Mar 7, 2017
Base term, 20 years from filing
Today
20 years from filing
2008 2028
Clock starts
Mar 21, 2008
Ends no later than
Mar 21, 2028
Granted
Mar 7, 2017
base term fee events Updated Nov 14, 2026 · includes USPTO assignment & status data published Nov 14, 2026 and grant & fee data published Nov 10, 2026 (weekly) · how we know
None
Term adjustment
No prosecution delay on this record.
Unresolved
Terminal disclaimer
On file, reference document not resolved, so the date above is an upper bound. We do not guess the cap.
2 of 2
Maintenance fees paid
Two maintenance fees can end this term early, the ones due 3.5 and 7.5 years from grant; the third one's grace period runs past the term end. This counts the ones the record shows paid.
16
Family applications on record here
Applications sharing this one's continuity chain whose file history this site holds. The family may have others.

This patent's term is its 20-year base term, with no adjustment for prosecution delay. A terminal disclaimer is on file with no resolved reference, so no cap is applied and none is guessed. 2 of 2 maintenance fees are paid so far. Confidence: Low. from the record

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.
StepInputDate after this stepConfidence
Base term, 20 years from filingClock starts Mar 21, 2008, when application 12/053,015, the earliest non-provisional in its chain, was filed (this one was filed Mar 12, 2015); a parent in its chain could not be resolved (the next row)Mar 21, 2028High confidence
Continuity chainA parent in the chain could not be resolveddated from this application's own claimMedium confidence
Patent term adjustmentNone on fileno changeHigh confidence
Terminal disclaimer capDisclaimer on file (approved), reference document not resolvedno cap applied, and none guessedMedium confidence
Patent term extensionNone on fileno changeHigh confidence
Fee events2 of 2 maintenance fees paidIn forceHigh confidence
Computed term endThe steps above, in orderno later than Mar 21, 2028Low confidence

This family

US 7,964,580In force
Mar 2029
Mar 2029
US 8,334,270In force
Mar 2028
Mar 2028
US 8,580,765In force
Mar 2028
Mar 2028
US 9,085,573In force
Mar 2028
Mar 2028
US 8,735,372In force
Mar 2028
Mar 2028
US 8,957,046In force
Mar 2028
Mar 2028
US 8,906,880In force
Mar 2028
Mar 2028
US 9,585,906this patent
no later than Mar 2028
no later than Mar 2028
8 of 16 applications in this family shown, earliest filings first. The applications whose file history this site holds. The family may have others.

Assignments

Assignment documents as recorded at the USPTO, oldest first, with the reel and frame each was recorded at. A recorded assignment is a filed document, not a statement of current ownership, and the absence of a later one is not evidence that the last one still stands.
RecordedAssignorAssigneeConveyance
Apr 7, 2015
Reel 35351, frame 87
Sofia, Michael Joseph; Du, Jinfa; Wang, Peiyuan; Nagarathnam, DhanapalanPharmasset, Inc.Assignment of Assignor's Interest
Apr 7, 2015
Reel 35386, frame 358
Pharmasset, Inc.Gilead Pharmasset LLCChange of Name
Jan 28, 2022
Reel 58890, frame 229
Gilead Pharmasset LLCGilead Sciences, Inc.Assignment of Assignor's Interest

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.

The Patent Finder CompaniesExpirationsCalculatorWatchlistPricing MethodologyCorrectionsLegalPrivacysupport@thepatentfinder.com Updated Nov 14, 2026 · includes USPTO assignment & status data published Nov 14, 2026 and grant & fee data published Nov 10, 2026 (weekly) Part of 137 Finder · © 2026 137 Finder LLC · Sources cited