Invalidity dossier
US 9233168
Oligomer-opioid agonist conjugates
Current assignee: Nektar Therapeutics
Added 9/21/2026, 10:32:23 AM
Active provider: DeepSeek · deepseek-flash
Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
Patent Overview — US 9,233,168 B2
Title: Oligomer-opioid agonist conjugates
Patent number / application: US 9,233,168 B2; application US 14/581,832; earlier publication US 2015/0112069 A1.
Inventors: Jennifer Riggs-Sauthier, Bo-Liang Deng, Timothy A. Riley.
Assignee: Nektar Therapeutics (original and listed current assignee in the excerpt). The excerpt also records security-interest assignments to Wells Fargo Bank and TC Lending, LLC, and later assignments to Inheris Pharmaceuticals, Inc., Inheris Biopharma, Inc., and back to Nektar Therapeutics.
Key dates: Priority date 2007-03-12; filing date 2014-12-23; publication date 2016-01-12; anticipated expiration 2028-03-12; legal status "Active."
Purpose / plain-language scope: The patent concerns conjugates in which an oligomer (the excerpt repeatedly uses "mPEG"/"PEG" and shows a methoxy-PEG chloride reactant) is attached to an opioid agonist. The disclosed chemistry illustrates PEGylation of opioid structures — for example, a morphinan-type compound bearing a phenolic OH reacted with mPEG-Cl to give a methoxy-PEG-aryl ether — and also shows nalbuphine-related and related opioid intermediates and nalbuphine-PEG conjugates. The abstract-like formula uses a morphinan core with variable substituents R1–R5 and a nitrogen substituent, indicating PEG/oligomer attachment at one or more positions.
Citing the supplied source: https://patents.google.com/patent/US9233168/en
What the excerpt does not establish: It does not prove claim scope, validity, enforceability, inventorship correctness, or freedom to operate. It does not establish clinical utility, dosing, safety, or regulatory status. It does not establish that ownership transfers are legally effective or current, nor does it determine the true legal priority date or expiration. It does not show the complete claims, specification, or prosecution history; omitted text may contain limitations not visible here. Finally, the excerpt does not demonstrate that any listed compound is within the granted claims or that the recited reactions were actually performed.
Generated 10/1/2026, 10:01:30 PM
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Litigation summary
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Proceedings on file (0)
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No PTAB proceedings on file. This patent has not been challenged via IPR, PGR, or CBM. The absence is itself a signal — well-asserted patents eventually attract IPRs. The LLM analysis below may surface filings the ODP feed hasn’t indexed yet.
PTAB challenges
AIA trial proceedings at the USPTO Patent Trial and Appeal Board — IPR, PGR, and CBM. Petitioners, judge panels, claim-level invalidation outcomes from Final Written Decisions, and Federal Circuit appeals. The single most important defensive datapoint after litigation history.
Assignment history
Inventors, original assignee, and the chain of ownership recorded with the USPTO — including the correspondent attorney who recorded each assignment, since shell-LLC chains often share one repeat-player attorney even when the entity names look unrelated. Surfaces NPE / patent-troll patterns: shell-entity transfers, known asserters in the chain, repeat correspondent fingerprints, pre-litigation assignments, and bankruptcy fire-sales.
Prior art
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Obviousness
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Extensions
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Derivative works
Defensive disclosure: derivative variations of each claim designed to render future incremental improvements obvious or non-novel.