Lapsed Jun 12, 2026 on the fee record · High confidence
20-year base term ends Dec 11, 2035
Second maintenance fee unpaid; grace period ended.
Held by Crystal Pharmatech Co., Ltd.
Filed Jun 12, 2017 as application 15/535,104 · Granted Jun 12, 2018
Base term, 20 years from filing
Today
Lapsed Jun 12, 2026
2015
2035
Clock starts
Dec 11, 2015
Dec 11, 2015
No longer in force
Jun 12, 2026
Jun 12, 2026
Granted
Jun 12, 2018
Jun 12, 2018
Term would have run to
Dec 11, 2035
Dec 11, 2035
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.
1 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.
3
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 Dec 11, 2035: 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.
| Step | Input | Date after this step | Confidence |
|---|---|---|---|
| Base term, 20 years from filing | Clock starts Dec 11, 2015, when application PCT/CN2015/097204, the earliest non-provisional in its chain, was filed (this one was filed Jun 12, 2017) | Dec 11, 2035 | High confidence |
| Continuity chain | Every parent in the chain resolved | no change | High confidence |
| Patent term adjustment | None on file | no change | High confidence |
| Terminal disclaimer cap | None on record | no cap applied | High confidence |
| Patent term extension | None on file | no change | High confidence |
| Fee events | 1 of 3 maintenance fees paid | lapsed Jun 12, 2026 | High confidence |
| Computed term end | The steps above, in order | Jun 12, 2026 | High confidence |
This family
| US 9,994,579 | this patent Jun 2026 | Jun 2026 |
| US 10,138,250 | In force Dec 2035 | Dec 2035 |
2 of 3 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.
| Recorded | Assignor | Assignee | Conveyance |
|---|---|---|---|
| Sep 14, 2017 Reel 43593, frame 645 | Chen, Minhua; Zhang, Yanfeng; Liu, Kai; Li, Jiaoyang; Zhang, Xiaoyu | Crystal Pharmatech Co., Ltd. | 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.
Free plan: 3 watched companies. Pro: unlimited.
Alerts on its grants, lapses and transfers.
Citations
8
later US patents cite this one
That is above the median of utility patents granted in 2018 in our data, the only group it is compared against.
How we rank
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.