US 9233165

I'll search for current information on this patent number before summarizing.

Let me dig deeper on litigation and the specific patent.

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US Patent 9,233,165 B2 — Summary

Important sourcing note: I do not have direct API access to USPTO PatentCenter/PAIR or the CAFC docket system. My findings below are grounded in the authoritative full-text record you supplied (Google Patents mirror of US9233165, fetched 2026-09-13), the patent PDF hosted at patentimages.storage.googleapis.com, and CourtListener (a third-party mirror of federal dockets). My CAFC-specific search returned no docket or appeal involving this patent number. Anything I cannot verify from those sources is flagged.

Bibliographic Data

Abstract (verbatim)

"The invention relates to (among other things) oligomer-aryloxy-substituted propanamine conjugates and related compounds. A conjugate of the invention, when administered by any of a number of administration routes, exhibits advantages over un-conjugated aryloxy-substituted propanamine compounds."

Technical Subject Matter

The patent covers PEG/oligomer conjugates of aryloxy-substituted propanamines — i.e., a small-molecule antidepressant/analgesic drug class whose exemplar is duloxetine, chemically identified in the specification as (+)-(S)-N-Methyl-3-(naphthalen-1-yloxy)-3-(thiophen-2-yl)propan-1-amine (the patent text says "(+)-(S)—N-Methyl…" and later "…propan-1-amine (duloxetine)"). The core structural concept is an aryloxy-substituted propanamine residue covalently attached, via a stable or degradable linkage (spacer "X"), to a water-soluble, non-peptidic oligomer ("POLY," preferably a short-chain PEG/oligoethylene glycol of ~1–30 monomers). Stated purpose: retain bioactivity while altering properties such as reduced blood-brain-barrier penetration and reduced metabolism.

The specification cites duloxetine-related prior patents U.S. Pat. Nos. 4,956,388; 5,023,269; and 5,362,886 as sources of aryloxy-substituted propanamines and synthetic routes.

Plain-Language Overview of the Independent Claims

⚠️ Uncertainty flag: The authoritative text supplied to me includes the Abstract, Definitions, and Detailed Description but does not include the literal claim set. The overview below is reconstructed from the "Summary of the Invention" and the Definitions section (which typically mirror the independent claims almost verbatim). I could not verify the exact claim language or claim count — treat wording as approximate.

The patent's Summary recites five distinct subject-matter families, consistent with independent claims directed to:

1. A compound (the conjugate itself). "A compound comprising an aryloxy-substituted propanamine residue covalently attached via a stable or degradable linkage to a water-soluble, non-peptidic oligomer." The compound claims are expressed as Markush structures (Formulas Ia, Ib and related) in which:

   • R¹ is C₅–C₇ cycloalkyl, thienyl, halothienyl, (C₁–C₄ alkyl)thienyl, furanyl, pyridyl or thiazolyl;
   • Ar is an optionally substituted aryl/condensed-ring system (e.g., naphthyl-type) bearing R⁴ (halo, C₁–C₄ alkyl, C₁–C₃ alkoxy, trifluoromethyl) and R⁵ substituents, with m = 0–2 and n = 0–1;
   • R² and R³ are independently hydrogen or methyl (or, in the narrower variant, R² is hydrogen or methyl);
   • X is a spacer moiety; and POLY is a water-soluble, non-peptidic oligomer (preferably oligoethylene glycol).
   • In plain terms: the drug molecule with a short PEG chain stapled onto it through a defined linker.

2. A composition. The conjugate above plus, optionally, a pharmaceutically acceptable excipient.

3. A dosage form. The conjugate presented in a dosage form (the disclosure emphasizes oral dosage forms such as tablets, caplets, capsules and the like).

4. A method of making. "Covalently attaching a water-soluble, non-peptidic oligomer to an aryloxy-substituted propanamine moiety" (conjugation chemistry is described at length — ether, amide, carbamate, carbonate, amine/reductive-amination, and similar linkages).

5. A method of administering / treating. Administering an effective amount of the conjugate to a patient (the specification frames the indication broadly around conditions responsive to antidepressant/analgesic therapy).

Litigation / Docket Search Results

• CAFC, 2026: My search returned no appeal or 2026 CAFC docket naming patent 9,233,165. I cannot confirm the absence of a docket from the CAFC's own filing system, only that no such docket surfaced in searchable public mirrors.
• District court: The only 2026-active Nektar litigation surfacing in the search is Nektar Therapeutics v. Eli Lilly & Co., No. 3:23-cv-03943-JD (N.D. Cal.) — a breach-of-contract dispute over Lilly's "commercially reasonable efforts" to develop REZPEG under a license agreement. This case does not involve patent 9,233,165 and is not a patent-infringement matter; I found no pleading in it asserting this patent.
• USPTO assignment history (per the patent record): Nektar Therapeutics → Nektar Therapeutics AL Corp. (2009); Nektar Therapeutics (2010); security interests to Wells Fargo (2012) and TC Lending (2015), both later released (2015, 2020). These are collateral/security filings, not litigation.

Foreign Family Members (for context, not US claims)

Corresponding family filings identified include EP 2265290 A1, WO 2009126333 A1, JP 2011516551 A, IL 208567 A0/A, and MX 2010011101 A — all titled "Oligomer-aryloxy-substituted propanamine conjugates" and all naming Nektar Therapeutics with the same priority date (2008-04-11).

Bottom line: US 9,233,165 is a Nektar Therapeutics composition-of-matter/medical-use patent (granted Jan. 12, 2016; adjusted expiry Sept. 1, 2031) covering short-PEG conjugates of aryloxy-substituted propanamines such as duloxetine. I found no patent litigation or CAFC 2026 appeal involving this specific number. If you need the literal claim text or a certified docket check, that should be pulled directly from USPTO PatentCenter and the CAFC electronic filing system, which were not directly accessible to me here.

I'll research litigation involving US patent 9233165 specifically. Let me run targeted searches.

Initial queries returned nothing. Let me try more specific sources.

Let me try more specific queries on litigation databases and the specific patent.

US Patent 9,233,165 — Litigation Search Results

Bottom line: I found no litigation specifically naming U.S. Patent No. 9,233,165. Based on the searches I was able to run, there are no district court cases, ITC actions, or PTAB proceedings identifiable as involving this patent.

Patent identification (verified, to avoid conflation)

Important disambiguation: The number 9,233,165 sits adjacent to two different Nektar patents that appear in search results — US 9,233,167 and US 9,233,168, both titled "Oligomer-opioid agonist conjugates" (priority 2007‑03‑12). Those are unrelated patents. I excluded them and did not treat them as this patent.

Litigation table

What the searches did and did not show

• Queries for "9233165", US patent 9233165 litigation, "9,233,165" infringement case, and Unified Patents litigation portal 9233165 returned no case records naming this patent. Two queries returned zero results.
• The Unified Patents litigation caselist (the site you suggested) is structured so that a patent-specific filter is applied via URL parameters; the search results surfaced the caselist tool itself and an example filtered to a different patent (10,213,2941), but no data for 9,233,165. I could not confirm a filtered caselist entry for this patent.
• The only Nektar-related records adjacent to the search were the sibling 9,233,167 / 9,233,168 patents (opioid-agonist conjugates) — not this patent and not litigation.
• The "reassignment" events visible in the patent record (Wells Fargo Bank and TC Lending LLC security interests in 2012 and 2015, with releases in 2015 and 2020) are secured-financing lien recordings, not litigation. They should not be counted as lawsuits.

Caveats and confidence

• Confidence: moderate-to-low that this is a complete negative. My tool access was limited (a small number of searches, no direct docket access to PACER, Docket Navigator, Lexis, Westlaw, or a live filtered Unified Patents caselist), and the search budget was exhausted before I could query the Unified Patents caselist directly by patent number or check Docket Navigator/Lexis Litigation Analytics.
• What would confirm a clean negative: a direct PACER/Docket Navigator query on the patent number; a LexisNexis or Westlaw litigation search; and a filtered Unified Patents caselist query (portal.unifiedpatents.com/litigation/caselist?patents=9233165). I could not complete these.
• I did not auto-correct or substitute any patent number. Where search results surfaced 9,233,167/9,233,168, I identified them as distinct.

Why an absence is plausible

US 9,233,165 is an oligomer–drug conjugate family patent (PEGylated aryloxy-substituted propanamines, i.e., duloxetine-type scaffolds) held by Nektar Therapeutics. Nektar's conjugation portfolio has generally been asserted or monetized in select programs (e.g., the opioid-agonist conjugate family, later moved to Inheris Pharmaceuticals), and the duloxetine/aryloxy-propanamine conjugate line does not appear to have generated public infringement suits. This is contextual reasoning only — not evidence of no litigation.

If you need a definitive answer, I recommend running the three verification searches listed above; I could not complete them here.

PTAB / AIA Trial Landscape — US 9,233,165 B2

"Oligomer-aryloxy-substituted propanamine conjugates" · Nektar Therapeutics · App. 12/936,894 · PCT filed 2009-04-13 · Granted 2016-01-12 · Priority 2008-04-11 · Adjusted expiration 2031-09-01

Proceedings overview

There are no AIA trial proceedings on file for US 9,233,165 B2 — zero IPRs, zero PGRs, zero CBM reviews. The USPTO Open Data Portal returns an empty proceeding list as of the most recent ingest, and my targeted web searches (Google Patents, PTAB/assignment aggregation and general litigation queries keyed to the patent number, the assignee "Nektar Therapeutics," the inventors Riggs-Sauthier / Duarte, and the subject matter "oligomer–aryloxy propanamine / duloxetine conjugate") surfaced no petition, institution decision, FWD or appeal touching this patent. The bottom-line defensive posture is therefore the inverse of the usual § 315(e)(2) story: there is no PTAB invalidation record to lean on, but also no estoppel wall blocking a defendant — the entire IPR toolbox is still open, unspent and un-tainted. Treat the patent as untested at the PTAB, not hardened.

⚠️ Confidence note / flag-as-instructed: I cannot rule out an older or very recently filed proceeding that the ODP has not indexed and that did not surface in my (rapidly capped) web searches. I found no evidence of one, and I am not inventing a proceeding number to fill the section template below. If you need a belt-and-suspenders check, query PTAB E2E / the USPTO Patent Trial and Appeal Board End-to-End system directly by the 12/936,894 application number and by patent 9,233,165 before you finalize a defense budget.

Per-proceeding detail

None. No proceeding exists to detail. For completeness, the template fields a defendant would expect resolve as follows:

• Type: n/a (no IPR / PGR / CBM on file)
• Filed: n/a
• Status: n/a — no structured status to quote
• Judge panel: n/a — no panel has ever been constituted
• Petition grounds: n/a — no § 102 / § 103 / § 112 challenge has been pleaded
• Institution decision: n/a
• Final Written Decision: n/a — no claim of 9,233,165 has ever been canceled or confirmed by the Board
• Settlement / termination: n/a
• Appeal: n/a — nothing to appeal to the Federal Circuit
• Defensive value: Neutral-to-favorable for a defendant. The absence of any prior petitioner means (a) no claim has been narrowed by adverse judgment and no statutory disclaimer appears on the face of the patent, and (b) no § 315(e)(2) estoppel attaches to you or to any real party in interest/privy — you may raise any § 102/§ 103 ground you can find, in any forum, without worrying that an earlier challenger "reasonably could have raised" it.

Strategic summary

Claim status: UNTESTED. Nothing in the public record indicates any claim of 9,233,165 has been canceled, disclaimed, or confirmed through an AIA trial. Because no FWD exists, I cannot and will not state that any specific claim (independent or dependent) is dead or alive — the claim set stands exactly as granted, subject only to whatever ordinary prosecution history and any (unconfirmed) certificates of correction or disclaimer may show. The patent carries an adjusted expiration of 2031-09-01, roughly two years of PTA beyond the nominal 2029 date, which raises the stakes of any invalidity fight: a defendant is buying exposure into the 2030s if the claims hold.

Estoppel landscape — the field is clear. § 315(e)(2) estoppel is petitioner-specific: it bars only a petitioner (and its RPI/privies) from raising grounds it raised or reasonably could have raised in a post-grant proceeding that reached FWD. With no prior petitioner, there is no estoppel shadow falling on anyone. Practically:

• A defendant can file a de novo IPR on any art it finds, including art that a hypothetical prior challenger would have found, with no "could have raised" trap.
• IPR estoppel cuts the other way too — because Nektar has never had to defend these claims at the Board, its own prosecution-history and priority story (the 2008-04-11 provisional priority, the PCT/US2009/002285 filing, the § 371 national stage) has never been stress-tested adversarially. That is fertile ground for a § 112 / priority / written-description attack that no one has yet mapped.
• Watch the real-party-in-interest question at petition drafting: if a supplier, joint-defense group, or indemnitor previously ran a challenge on a related Nektar oligomer patent in the same family, privity arguments could theoretically be raised against you even here — so confirm no affiliate has previously petitioned on the sibling oligomer-family patents before you rely on the clean estoppel slate.

Pattern signals. (1) Same-petitioner pattern: none observable — there is no petitioner to repeat. (2) Patent-owner appeal aggressiveness: Nektar has been an active life-sciences patent owner and assignor of record (multiple security-interest reassignments to Wells Fargo, then TC Lending, with releases recorded in 2015 and 2020), so it is a sophisticated patent holder, but there is no PTAB/Federal Circuit appellate track record on this patent to read. (3) Defensive aggregator: I found no indication that Unified Patents, RPX, or any similar aggregator has taken up this patent — the Unified Patents portal pages that surfaced in search were for other Nektar oligomer patents (e.g., US 10,143,690; US 9,782,488; US 9,827,239) and did not list 9,233,165 as a subject patent. Do not assume a third party has already fronted a validity challenge for you; on this record, you would be the first.

The signal in the silence. A patent granted in 2016 that has never drawn a single AIA petition is informative. Either (a) it has never been asserted in a commercially meaningful way, so no defendant has had the incentive to spend $500K–$1M on a post-grant challenge; or (b) it has been asserted but targets settled/declined to fight before the Board. Both readings favor a fresh petitioner: the claims have not been paired down, the prior-art record before the Office is whatever the examiner assembled years ago, and there is no adverse Board claim construction to work around.

Recommended next steps

1. Verify the null result directly before budgeting. Pull PTAB E2E and the USPTO PatentCenter record for application 12/936,894 / patent 9,233,165 and confirm no IPR/PGR/CBM and no certificate of correction or statutory disclaimer. The ODP feed is the canonical source here, but a one-time direct check is cheap insurance.
2. Mine the priority chain before you draft art. The patent claims benefit of PCT/US2009/002285 and U.S. Provisional 61/123,929 (2008-04-11). No one has ever litigated that priority claim. Build the § 112 / priority timeline first — it may define your effective prior-art date more favorably than the face of the patent suggests.
3. Identify sibling patents before choosing a venue. Nektar's oligomer-platform family is large (oligomer–opioid, oligomer–cannabinoid, oligomer–tricyclic, oligomer–beta-blocker conjugates, etc., several of which the search results show issuing from the same 2007–2008 priority window). A single IPR on 9,233,165 does not clear the portfolio; map the family and consider whether a joint or serial challenge strategy makes sense.
4. Estoppel is a blank slate — spend it deliberately. Because nothing is on file, you have no prior-petitioner art record to inherit and no estoppel risk from someone else's failed challenge. That means the first petitioner can pick the strongest art set freely; conversely, if you are not the first, you inherit full § 315(e)(2) exposure from your own filing. Decide early whether to lead.
5. No active-proceeding milestones to track. There is no institution-deadline, no oral-hearing date and no statutory 1-year FWD clock running against anyone — because there is no trial. If you file, the clock starts at institution (35 U.S.C. § 316(a)(11)).

Source links

• Patent text (authoritative): https://patents.google.com/patent/US9233165/en
• PTAB decisions portal (verify null result by patent number): https://www.uspto.gov/patents/ptab/decisions
• PTAB E2E (proceeding search): https://ptab.uspto.gov/
• CourtListener (Federal Circuit docket search): https://www.courtlistener.com/

No proceeding number is cited above because none exists on the record I could retrieve. I have not fabricated an IPR/PGR/CBM number, petitioner, panel, or disposition.

I'll research the assignment record for US 9,233,165 before drafting. Let me run targeted searches.

Let me dig for the specific reel/frame records and the TC Lending security interest.

US Patent 9,233,165 — Ownership Chain Reconstruction

Data caveat up front: The authoritative source (the full patent text retrieved from Google Patents) exposes the legal events but not every reel/frame or the correspondent of record. I could not reach USPTO Assignment Center directly (search budget exhausted), so reel/frame values below are marked [confirmed] (stated in the patent record), [cross-referenced] (taken from the identically dated Nektar portfolio recording on a sibling patent), or [unknown]. No value is fabricated. Correspondent of record was not retrievable from my sources — I flag that as a gap rather than guess.

Inventors

Pattern check: No unusual inventor-side signal. Several Nektar conjugations from this era were filed in the Huntsville/AL (ex‑Shearwater) group, and both inventors appear as assigning to Nektar, not departing with rights. I found no evidence of either inventor leaving within 12 months of filing, nor of any inventor retaining or later re‑acquiring rights — but this is an absence of evidence, not a confirmed clean bill.

Original assignee

• Entity on the issued patent: Nektar Therapeutics (with Nektar Therapeutics AL Corp also listed as an assignee on the early record).
• Primary line of business: Operating pharmaceutical company — PEGylation / polymer–drug conjugate chemistry and a clinical pipeline (NASDAQ: NKTR). It is a going concern, not an NPE.
• Product embodying the claims: Unclear / likely none. The claims are drawn to oligomer-conjugated aryloxy-substituted propanamines (a PEGylated duloxetine-type scaffold). I found no evidence Nektar ever commercialized a product reading on these specific claims; the family reads as research-stage/drug-discovery IP. Nektar's revenue-bearing patents in this period concern PEGylation platform technology and supply/licensing (e.g., CIMZIA, MIRCERA), which are distinct subject matter.
• Current status: Operating, publicly traded. No bankruptcy, no dissolution. (Its 2015 secured note issuance and the security interests discussed below are ordinary corporate financing, not distress events — the note was repaid/redeemed and the liens released, per SEC/8‑K filings and the 2016 10‑K.)

Assignment timeline

Chronological. Ownership-transferring conveyances are bolded; the remainder are financing liens (security interests) and releases, which are not ownership changes and must not be counted as NPE transfers.

1. 2009-05-19 (recorded 2009-05-19) — Reel [unknown]

   • Conveyance: Assignment (inventor→company, initial/obligation assignment)
   • Assignor: Franco J. Duarte; Jennifer Riggs-Sauthier
   • Assignee: Nektar Therapeutics AL, Corporation
   • Correspondent: [unknown — not retrievable from my sources]
   • Context: Ordinary employment-assignment of the inventors' rights to the originating Nektar subsidiary (AL / Huntsville group).

2. 2010-12-06 (recorded 2010-12-06) — Reel [unknown]

   • Conveyance: Assignment (confirmatory, coincident with §371 national-stage entry of PCT/US2009/002285 → App. 12/936,894)
   • Assignor: Franco J. Duarte; Jennifer Riggs-Sauthier
   • Assignee: Nektar Therapeutics
   • Correspondent: [unknown]
   • Context: Confirmatory/second-look assignment into the ultimate parent, Nektar Therapeutics — internal housekeeping, not a third-party transfer.

3. 2012-07-17 (recorded 2012-07-17) — Reel 028571/0141 [confirmed by the patent's own release event: "REEL 28571, FRAME 0141"]

   • Conveyance: Security Agreement — "Grant of Security Interest"
   • Assignor: Nektar Therapeutics
   • Assignee: Wells Fargo Bank, National Association, as Collateral Agent
   • Correspondent: [unknown]
   • Context: Securitization (collateral pledge under a Nektar secured financing) — not an ownership transfer.

4. 2015-10-06 (recorded 2015-10-06) — Reel 036796/0562 [cross-referenced — same-date, same-conveyance Nektar portfolio filing on sibling patent US 7,078,496; not independently confirmed on this patent]

   • Conveyance: Security Agreement — "Grant of Security Interest in United States Patents"
   • Assignor: Nektar Therapeutics
   • Assignee: TC Lending, LLC, as Collateral Agent (Fort Worth, TX — 301 Commerce Street, Suite 3300)
   • Correspondent: [unknown]
   • Context: Securitization tied to Nektar's $250M 7.750% Senior Secured Notes due 2020 (Indenture and Pledge & Security Agreement dated 2015‑10‑05; recorded per the 8‑K of 2015‑10‑06). Blanket lien over substantially all Nektar IP; not an ownership transfer.

5. 2015-10-14 (recorded 2015-10-14) — Reel 036866/0700 [cross-referenced from the same Nektar release event on sibling patent US 7,078,496]

   • Conveyance: Release — "Release of Security Interest recorded at Reel 28571, Frame 0141"
   • Assignor: Wells Fargo Bank, National Association, as Collateral Agent
   • Assignee: Nektar Therapeutics
   • Correspondent: [unknown]
   • Context: Discharge of the 2012 Wells Fargo lien upon repayment of the underlying secured notes (the proceeds of the TC Lending notes were used to redeem the prior secured notes).

6. 2016-01-12 — grant of the patent; no conveyance tied to issuance.

7. 2020-04-17 (recorded 2020-04-17) — Reel [unknown] (a TC Lending "Release by Secured Party" around this period was recorded at 053180/0009 on a different Nektar-inherited record; [cross-referenced, unconfirmed for this patent])

   • Conveyance: Release — "Release of Security Interest" (TC Lending)
   • Assignor: TC Lending, LLC, as Collateral Agent
   • Assignee: Nektar Therapeutics
   • Correspondent: [unknown]
   • Context: Discharge of the 2015 TC Lending lien following repayment of the 2020 notes; leaves Nektar as sole owner.

Note on the "reassignment" entries shown on Google Patents: the 2015‑10‑14 and 2020‑04‑17 events are releases in favor of Nektar, not transfers away from it. A naive reading of the "Assigned to … RELEASE OF SECURITY INTEREST" labels could be misread as new ownership; they are the opposite. My earlier litigation note reached the same conclusion (lien recordings ≠ lawsuits), and this analysis is consistent with it.

Timeline diagram

timeline
    title Ownership of US 9233165
    2008 : Priority provisional filed
    2009 : PCT application filed
         : Inventors assign to Nektar AL Corp
    2010 : Confirmatory assignment to Nektar
    2012 : Security interest to Wells Fargo
    2015 : Security interest to TC Lending
         : Wells Fargo lien released
    2016 : Patent granted
    2020 : TC Lending lien released

NPE / troll-pattern signals

Verdict

Insufficient data — but for a specific, benign reason: the ownership chain is essentially a single original assignment.

Justification: The only recorded ownership transfers are inventor→Nektar (2009‑05‑19) and the confirmatory AL Corp→Nektar assignment (2010‑12‑06); every subsequent recording is a security interest or its release — Wells Fargo at Reel 028571/0141 (2012‑07‑17), TC Lending at Reel 036796/0562 [cross-ref] (2015‑10‑06), and the corresponding releases (2015‑10‑14; 2020‑04‑17) — which return full ownership to Nektar rather than moving it to any third party. No shell-entity transfer, no known asserter, no cascading LLCs, no fire-sale, and no pre-suit transfer were found, and the chain terminates at the original operating-company assignee. The one unresolved item is the correspondent of record (Signal 3), which I could not retrieve — confirming that would upgrade this from "insufficient data" to a clean operating-company, non-asserting call; note that no rubric category exactly fits a patent that stayed with its operating originator and was never asserted.

Verify at: https://assignmentcenter.uspto.gov/ (search patent number 9233165) — and specifically pull the correspondent fields on the 2009‑05‑19 and 2010‑12‑06 recordings to close Signal 3, plus confirm Reels 036796/0562 and 036866/0700 apply to this patent and locate the 2020‑04‑17 TC Lending release reel/frame.

I'll research the cited prior art for US 9,233,165. Let me run targeted searches.

I now have the front-page "References Cited" list. Let me verify the key references and their bibliographic details.

I reached my search-step limit mid-verification, so I'll flag precisely what I did and did not confirm. Below is the prior-art analysis built on the authoritative front-page "References Cited" list I retrieved from the granted patent PDF (patentimages.storage.googleapis.com/04/a4/f1/b23750c3287896/US9233165.pdf) and the pre‑grant publication text (US 2011/0071207 A1).

Prior-Art Analysis — US 9,233,165 B2

0. Critical framing before the list

Three cautions up front, because they materially affect how you read the "§ 102" column:

1. "References Cited" ≠ "references applied as anticipatory art." The list on the face of US 9,233,165 is a mixture of (a) art the examiner applied, (b) art cited in the specification's own background (duloxetine syntheses), and (c) a large block of IDS-type catalog/trade literature (Nektar, NOF, Quanta Biodesign, Polypure, Shearwater catalogs). The catalog material is there to document the state of the PEG-reagent art, not to anticipate. Without the file wrapper / examiner's reasons for allowance I cannot say which were actually applied under § 102 vs. § 103.

2. The literal granted claim set is 3 claims; I only have the published application's 22 claims. The face of US 9,233,165 says "3 Claims, No Drawings." The claim text I can quote verbatim (claims 1–22, from US 2011/0071207 A1) is the pre-grant set and is therefore only an approximation of the granted claims. I flag this explicitly; do not treat my claim mapping as a mapping onto the literal granted claims. (Consistent with the earlier summary's uncertainty flag.)

3. One important inter-family data point: the EP counterpart (EP 2265290 B1) granted with claims limited to "a poly(alkylene oxide)" rather than the broader "water-soluble, non-peptidic oligomer," and its specification expressly identifies US 2006/0281722 as prior art ("charge-modified antidepressants… conjugated to either a charged group or a bulky group in a manner that resists in vivo cleavage"). That tells you the family's prosecution treated the Foley reference as the closest art and narrowed to survive it.

1. U.S. Patent Documents cited on the face of US 9,233,165

Dates are given as printed on the patent face where I verified them against independent records; where the printed date appears garbled I say so and do not silently correct the number.

Foreign Patent Documents cited:

Selected "Other Publications" (non-patent literature) — only the substantively important ones:

• Kuo, F. et al., "Synthesis and biological activity of some known and putative duloxetine metabolites," Bioorg. Med. Chem. Lett. 14 (2004) 3481–3486 — the most chemically relevant NPL: duloxetine metabolite structures. § 103/background; reinforces that the propanamine core was well-characterized.
• Bymaster et al., Neuropsychopharmacology 25(6):871–880 (2001) — duloxetine vs. venlafaxine pharmacology. Background bioactivity art for the "maintain bioactivity" limitation.
• Chen & Baker, J. Org. Chem. 64:6870–6873 (1999) and Zhao et al., J. Org. Chem. 66:7035–7043 (2001) — oligomer/self-assembly chemistry, cited for monodisperse oligomer synthesis.
• The large Shearwater / Nektar / NOF / Quanta Biodesign / Polypure catalog block (1995–2006) — documents commercial availability of monodisperse PEG reagents; § 103 background on the oligomer element only.

2. What the claims require (basis for the anticipation screen)

From the published application (US 2011/0071207 A1), the independent claims are:

• Claim 1 – a compound comprising an aryloxy-substituted propanamine residue covalently attached via a stable or degradable linkage to a water-soluble, non-peptidic oligomer.
• Claim 19 – a composition (conjugate + optional pharmaceutically acceptable excipient).
• Claim 20 – a composition of matter in a dosage form.
• Claim 21 – a method of making (covalently attaching the oligomer to the propanamine).
• Claim 22 – a method of treatment (administering the conjugate).
• Dependent claims 2–7 define the Markush structures / residue; 8–14 the oligomer type/size; 15–18 the linkage type (stable vs. degradable; ether; ester).

For anticipation under § 102, a single reference must disclose every element — critically, (i) the aryloxy-substituted propanamine residue and (ii) the covalently attached water-soluble, non-peptidic oligomer, arranged as in the claim.

3. Anticipation (§ 102) analysis

Bottom line: none of the cited references anticipates the claims of US 9,233,165. They split cleanly into (A) art that discloses only the propanamine half and (B) art that discloses only the oligomer/reagent or delivery-vehicle half. Anticipation is only conceivable if a single reference bridges both halves — and the one reference that comes closest (Foley, US 2006/0281722) does so with a charged/bulky group, not a water-soluble non-peptidic oligomer.

Group A — disclose the propanamine half only (relevant to claims 2–7, 6–7):
US 4,956,388; US 5,023,269; US 5,362,886; US 3,674,840. These collectively render the aryloxy-propanamine (duloxetine-type) residue old in the art, but each lacks any oligomer limitation. → § 103 material at most; no § 102 anticipation of any independent claim.

Group B — disclose the oligomer/reagent or vehicle half only (relevant to claims 8–14, and the delivery-vehicle disclosure):
US 5,672,662; US 2005/0136031; US 2006/0275252; the WO PEG/conjugate references; the glucan patents (US 4,810,646; US 4,992,540; US 5,607,677; US 5,741,495; US 2005/0281711; US 2008/0044438). Each lacks the aryloxy-propanamine residue. → § 103 material; no § 102 anticipation.

The one reference worth a hard look — US 2006/0281722 A1 (Foley et al.):

• If it disclosed a duloxetine-type antidepressant linked to a poly(ethylene glycol)/oligo(ethylene glycol), it would potentially anticipate claim 1 (and the residue/oligomer dependents).
• But the EP family's own characterization is that Foley discloses linkage to "either a charged group or a bulky group in a manner that resists in vivo cleavage." A charged group (e.g., a quaternary ammonium/sulfonate) or a "bulky group" is not necessarily a "water-soluble, non-peptidic oligomer," and the linkage there is expressly non-cleavable, whereas claim 1 permits a degradable linkage. Those are genuine claim-element gaps.
• Net: § 103 (obviousness) art, not § 102 anticipation — which is consistent with the EP counterpart granting with claims narrowed to "poly(alkylene oxide)."
• Caveat: I was not able to pull the full text of US 2006/0281722 within the search budget. If its disclosure in fact enumerates PEG/oligo-ethylene-glycol conjugates of a duloxetine-type propanamine, the § 102 picture for claim 1 as published changes and you should re-run the analysis against its actual paragraphs.

4. Ranking — most to least relevant

1. US 2006/0281722 A1 (Foley et al.) — only cited reference that arguably bridges both halves (charged/bulky-group antidepressants). Closest art; § 103 unless its full text discloses a PEG/oligo-EG conjugate.
2. US 5,672,662 A (Harris et al.) — foundational PEG-active-ester conjugation art; bears directly on the oligomer + linkage elements (claims 8–18).
3. US 5,023,269 A and US 4,956,388 A (Robertson et al.) — the duloxetine composition-of-matter patents; they make the propanamine residue old (claims 2–7).
4. US 5,362,886 A (Berglund) — duloxetine asymmetric synthesis; enables the residue and supplies the synthetic chemistry mirrored in the '165 Examples.
5. US 2005/0136031 A1 (Bentley et al.) — monodisperse PEG-oligomer preparation (the oligomer element; claims 8–14).
6. The glucan/yeast-particle family (US 4,810,646; 4,992,540; 5,607,677; 5,741,495; 2005/0281711; 2008/0044438) — delivery-vehicle disclosure only; peripheral.
7. Remaining WO/JP items and the catalog literature — background/IDS material.

5. Explicit uncertainty log

• I did not access the USPTO file wrapper, so I cannot tell you which references the examiner actually applied under § 102/§ 103 vs. which were applicant/IDS-submitted. The catalog block strongly suggests IDS origin.
• I could not verify the full disclosures of US 2006/0275252, the WO references, JP 51-23488, or US 2006/0281722. Statements about those are flagged as unverified above; do not treat my one-line descriptions of the WO/JP items as confirmed.
• Claim mapping uses the published 22-claim set (US 2011/0071207 A1), not the 3 granted claims, whose literal text I do not have. If you need the anticipation screen run against the exact granted claims, pull the granted claim set from USPTO PatentCenter.
• Apparent transcription/OCR issues I flagged rather than corrected: "US 5,607,703 A, 7/1991"; "US 5,362,886 A, 11/1991" (actual 11/8/1994); spec "WO 02/098949" vs. face "WO 02/099949"; spec "US 5,028,703" vs. face "US 5,607,703."
• Date note: the task header says "Current Date: April 26, 2026" while the working environment reports 2026-09-14. I have not relied on either for any substantive conclusion.

If you want, tell me whether to (a) pull the literal granted 3-claim text, or (b) retrieve the full text of US 2006/0281722 to settle whether it is § 102 or § 103 art — those are the two steps that would tighten this analysis most.

I'll research the prior art landscape for this § 103 analysis, starting with the references cited on the patent's face and in its text.

Let me pull the specific prior-art references cited on the patent's face and the foundational Nektar conjugate application.

Obviousness Analysis — U.S. Patent No. 9,233,165 B2 under 35 U.S.C. § 103

Patent: US 9,233,165 B2, "Oligomer-aryloxy-substituted propanamine conjugates"
Assignee: Nektar Therapeutics · Inventors: Riggs-Sauthier & Duarte
Priority: April 11, 2008 (Prov. 61/123,929) · §371 filed: April 13, 2009 · Granted: Jan. 12, 2016

0. Scope, governing law, and a mandatory caveat

Governing framework. Because the application was filed before March 16, 2013, pre-AIA § 103(a) applies. The analysis follows Graham v. John Deere, 383 U.S. 1 (1966), as refined by KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007) — scope/content of the prior art, differences, PHOSITA level, and secondary considerations. Under KSR, a claimed combination is obvious where (i) the prior art elements were known, (ii) there was a finite number of identified, predictable solutions, and (iii) there was a reasonable expectation of success. An express "teaching, suggestion, or motivation" is no longer required; market/design need and common sense suffice.

⚠️ Caveat on the record (unchanged from prior sections). The authoritative text supplied to me contains the Abstract, Summary, Definitions, Detailed Description, and Examples, but not the literal claim set, and the Google Patents mirror as fetched does not include the front-page "References Cited" list. Accordingly:

• Claim reconstruction below is drawn from the patent's own Summary of the Invention (which conventionally mirrors the independent claims verbatim) and the Definitions section. Treat the wording as approximate.
• The "Prior Art section of this page" available to me consists of (a) the stated prior-art keyword set — "oligomer, aryloxy, water, group, soluble" — and (b) the references cited in the specification text. Where I rely on art surfaced by search rather than cited on the face, I say so explicitly.
• Patent numbers are reproduced literally from the sources. Do not treat any apparent near-duplicate as interchangeable.

1. The claimed invention, reduced to its inventive core

Stripped of Markush boilerplate, every independent claim reduces to a three-element combination:

Critical observation: the element-A Markush definitions in US 9,233,165 — including the specific recitation of "each R⁴ independently is halo, C₁–C₄ alkyl, C₁–C₃ alkoxy or trifluoromethyl; each R⁵ independently is halo, C₁–C₄ alkyl or trifluoromethyl; m is 0, 1 or 2; and n is 0 or 1" — are verbatim the substituent definitions of the prior-art 3-aryloxy-3-substituted propanamine genus. Element A is therefore admitted prior art on the face of the patent itself. The patent expressly concedes this: "Examples of aryloxy-substituted propanamines as well as synthetic approaches for preparing aryloxy-substituted propanamines are described in the literature and in, for example, U.S. Pat. Nos. 4,956,388, 5,023,269 and 5,362,886."

The entire novelty of US 9,233,165 thus resides in elements B + C — i.e., putting a short PEG chain on a known antidepressant. That framing drives everything below.

2. The prior art of record

2.1 Art cited in the specification (admissions against interest)

2.2 Art surfaced by search (not on the face; verify before reliance)

⚠️ Discrepancy flag. One secondary source (the Justia page for US 7,538,232) recites the Lilly synthesis patents as "U.S. Pat. Nos. 5,362,866 and 5,491,243." Every primary source I retrieved — including the patent at issue here and the Lilly EP 0 650 965 A1 front matter — identifies the asymmetric-synthesis patent as US 5,362,886. I am reproducing 5,362,866 literally where the secondary source says it, but treating 5,362,886 as the operative citation. This is not a correction of either number; it is a note that the two sources diverge.

3. Element-by-element obviousness mapping

Every element is disclosed. The question is purely whether the combination is obvious. It is.

4. The § 103 combinations

Combination 1 (primary): US 4,956,388 + US 2005/0136031

This is the strongest ground. Take the duloxetine genus of US 4,956,388 as the drug; take the O–X–D platform of US 2005/0136031 as the oligomer-plus-linker; combine.

Motivation to combine — KSR rationales, in order of strength:

1. Express teaching of the very advantage claimed. US 2005/0136031 states, in haec verba, that attaching a water-soluble oligomer to a small-molecule drug "effectively diminishes the ability of the resulting conjugate to cross certain biological membranes, such as those associated with the blood-brain barrier," and gives numeric targets (≥10%–90% retained oral bioavailability; reduced first-pass metabolism). US 9,233,165 claims exactly those outcomes. When a reference names the problem and the solution, the motivation is not merely adequate — it is explicit.

2. The patent's own admission. US 9,233,165 concedes element A is old and cites US 2005/0136031 as the source of its oligomer technology ("Water-soluble, non-peptidic oligomers can be prepared as described in … WO 02/098949, and U.S. Patent Application Publication 2005/0136031"). A patent cannot simultaneously admit the platform and the drug and claim the joinder as inventive.

3. Same assignee, same inventors, same laboratory. US 2005/0136031 is a Nektar application (Bentley et al.). US 9,233,165 is Nektar (Riggs-Sauthier & Duarte). The "motivation" is the ordinary course of a platform program: the 2003 application teaches the generic method; the 2008 application applies it to the next drug class. KSR expressly holds that where the prior art is a general method and the applicant merely applies it to a new field using known techniques, the result is likely obvious.

4. Finite, predictable set of solutions. US 2005/0136031 already bounds the search space: oligoethylene oxide monomers, 1–25 in series, monodisperse; linkages limited to ether/amide/urethane/amine/thioether/C–C; drug = any small molecule bearing a free hydroxyl, amino, carboxyl, thiol, or aldehyde "handle." Duloxetine's secondary N-methyl amine is precisely such a handle — and, as the patent itself notes, the S-enantiomer and its N-demethylation chemistry are disclosed in US 5,362,886. A PHOSITA "has good reason to pursue the known options within his or her technical grasp." KSR, 550 U.S. at 421.

5. The "substitution of a known reagent for a known purpose" corollary. US 5,672,662 supplies activated mPEG-SPA/SBA succinimidyl esters that react with amines to give hydrolytically stable amide linkages. Substituting that known PEGylating reagent onto the known duloxetine amine is the paradigm of an obvious substitution of materials — "the improvement of one material over another for no reason other than design necessity" is not patentable subject matter. KSR, 550 U.S. at 416.

Combination 2: US 4,956,388 + US 5,672,662 + WO 02/098949 (+ Zalipsky 1983)

A tighter, three-reference variant that avoids any reliance on the later-published US 2005/0136031, if a defendant prefers art with earlier dates:

• US 4,956,388 → the drug genus and the amine handle.
• Zalipsky 1983 → "attach PEG to drugs," with the classic listing of PEG-drug conjugations.
• US 5,672,662 → the specific reactive PEG (SPA/SBA) needed to make a stable amide to the drug's amine.
• WO 02/098949 → monodisperse oligomer synthesis, supplying element C's "monodisperse" limitation.

Motivation: Zalipsky's review is a "why would you not?" teaching — it comprehensively catalogs attaching PEG to drugs to alter solubility, stability, and pharmacokinetics. The Federal Circuit has repeatedly held that a reference disclosing a broad class of PEG–drug conjugates, together with a known drug and a known reactive PEG, renders the specific conjugate obvious absent a non-obvious, unexpected property. Cf. In re Peterson, 315 F.3d 1325 (Fed. Cir. 2003) (narrowing a disclosed range to a preferred sub-range is obvious absent evidence of criticality).

Combination 3: The Nektar sibling-patent family as a "same method, different drug" teaching

The record shows the identical "X is a spacer moiety; POLY is a water-soluble oligomer" + BBB-reduction template applied by the same assignee to corticosteroids, opioid agonists, calcium channel blockers, nucleoside phosphates, and 3-alkoxypropionamides. Applying an established, uniformly successful conjugation methodology to one more known drug class is ipso facto obvious under the KSR "predictable use of a known technique" rationale.
⚠️ Timing caveat: several siblings carry 2007–2008 priorities. Each must be individually qualified as § 102(e) or § 103 art. Do not cite the family generically.

5. Reasonable expectation of success

A PHOSITA at April 11, 2008, would have had every reason to expect the conjugation to work:

• The chemistry is routine. Amide coupling of an activated PEG ester to a secondary amine, and reductive amination of an aldehyde-PEG onto an amine, are described in US 2005/0136031 and US 5,672,662 with working examples.
• The "handle" is present. Duloxetine's N-methyl secondary amine is a nucleophile; the patent itself states "a small molecule having an aldehyde function is coupled to an oligomer amino group by reductive amination" and "Most small molecule drugs for covalent attachment to an oligomer will possess a free hydroxyl, amino, thio, aldehyde, ketone, or carboxyl group."
• The outcome was predicted in advance. US 2005/0136031 predicted reduced BBB crossing and retained oral bioavailability for the generic O–X–D class. The patent's asserted advantages are therefore not "unexpected results" — they are the expected results of a generic teaching, which severs any nexus for secondary considerations. See In re Kao, 639 F.3d 1057, 1068 (Fed. Cir. 2011) (secondary considerations require nexus to the claimed invention, not to a property disclosed in the prior art).

6. Anticipated § 103 counterarguments, and how they fare

7. Claim-differentiation: which claims are most exposed

8. Bottom line

US 9,233,165 is, in substance, a two-reference obviousness case. The patent's element A is admitted prior art — the very Markush definitions are copied from US 4,956,388, and the specification names US 4,956,388, 5,023,269 and 5,362,886 as sources of the drug. Element C (and the claimed functional benefits) are taught in US 2005/0136031, which the patent itself cites and which expressly recites reduced blood-brain-barrier crossing, retained oral bioavailability, and reduced first-pass metabolism. Element B is a menu of routine linkages supplied by US 2005/0136031, US 5,672,662, and Zalipsky (1983).

The strongest ground is US 4,956,388 + US 2005/0136031, motivated by (i) the express teaching of the exact advantage claimed, (ii) the same-assignee/same-platform continuity, (iii) the finite, enumerated solution space, and (iv) KSR's predictable-use and obvious-to-try rationales. The US 4,956,388 + Zalipsky + US 5,672,662 + WO 02/098949 combination is a date-safer alternative.

The patent's best defenses are teaching away (CNS drugs "need" BBB penetration) and unexpected results (retained bioactivity at short oligomer lengths) — but both are substantially undercut by Nektar's own 2003 application, which taught the strategy generically for CNS-active small molecules and predicted the very properties now claimed. The patent record as supplied contains no comparative data to support the unexpected-results argument.

Because no AIA trial has ever been filed (per the prior PTAB section), these claims are untested, un-narrowed, and carry no § 315(e)(2) estoppel shadow. The art set above has never been presented to the Board.

9. Verifications I could not complete (flagging, not fabricating)

1. The literal claim set — pull from USPTO PatentCenter (App. 12/936,894). Everything in §7 is provisional.
2. The front-page "References Cited" list of US 9,233,165 — the fetched mirror omitted it. If the examiner cited art beyond the specification's citations (e.g., a § 102(e) Nektar sibling or a third-party PEG–antidepressant reference), that art is in the file wrapper and should anchor the petition.
3. Whether US 2005/0136031 expressly names duloxetine or aryloxy-propanamines — I could not confirm the reference's full drug list from the retrieved excerpts. If it does name them, this case approaches anticipation and the § 103 analysis becomes near-dispositive.
4. Date-qualification of each Nektar sibling oligomer-conjugate filing as § 102(b)/(e) art — critical, and not yet done.
5. The 2008-04-11 provisional's § 112 support for the full Markush — untested; may shift the prior-art date.

Confidence: moderate-to-high on the substance of the obviousness case (the two-reference combination is well grounded in the record). Low on the claim-level conclusions, pending retrieval of the literal claims. I have not auto-corrected any patent number; where sources diverge (5,362,886 vs. 5,362,866), I have flagged rather than reconciled.