The Patent Finder
US

Relaxin Polypeptides Comprising Non-Naturally Encoded Amino Acids

US 8,735,539 Lapsed on the fee record
OverviewFamilyAssignmentsSources & methods

Lapsed May 27, 2026 on the fee record · High confidence

Third maintenance fee unpaid; grace period ended.

Held by Ambrx, Inc.
Filed Aug 17, 2011 as application 13/212,101 · Granted May 27, 2014
USPTO first gave this application the number US 8,691,940 and withdrew it before it issued. That number now leads here.
Base term, 20 years from filing
Today
Lapsed May 27, 2026
2011 2031
Clock starts
Aug 17, 2011
No longer in force
May 27, 2026
Granted
May 27, 2014
Term would have run to
Aug 17, 2031
base term after the term ends 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.
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.
12
Family applications on record here
Applications sharing this one's continuity chain whose file history this site holds. The family may have others.

Its term would have run to Aug 17, 2031: its 20-year base term, with no adjustment for prosecution delay. Confidence: High. 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 Aug 17, 2011, when this application, 13/212,101, was filedAug 17, 2031High confidence
Continuity chainEvery parent in the chain resolvedno changeHigh confidence
Patent term adjustmentNone on fileno changeHigh confidence
Terminal disclaimer capNone on recordno cap appliedHigh confidence
Patent term extensionNone on fileno changeHigh confidence
Fee events2 of 3 maintenance fees paidlapsed May 27, 2026High confidence
Computed term endThe steps above, in orderMay 27, 2026High confidence

This family

US 8,735,539this patent
May 2026
May 2026
US 9,567,386In force
Nov 2031
Nov 2031
US 9,452,222In force
Aug 2031
Aug 2031
US 9,962,450Lapsed on the fee record
May 2026
May 2026
US 10,253,083In force
Aug 2031
Aug 2031
US 10,702,588In force
Aug 2031
Aug 2031
US 10,751,391In force
Aug 2031
Aug 2031
US 11,311,605Lapsed on the fee record
Apr 2026
Apr 2026
8 of 12 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
Jun 28, 2012
Reel 28464, frame 689
Kraynov, Vadim; Knudsen, Nick; Hewet, Amha; De Dios, Kristine; Pinkstaff, Jason; Sullivan, LorraineAmbrx, 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