US 5023269

I'll search for authoritative information on this patent number.

Let me search for the claims text and any 2026 litigation activity.

Let me search for the actual claim text and any recent Federal Circuit activity.

Summary — US Patent 5,023,269

Caveat on scope of search: I was able to retrieve the patent's own bibliographic and disclosure data (Google Patents full text provided) plus secondary sources (DrugPatentWatch, Stanford NPE Litigation Database, Orange Book listings). I found no CAFC docket activity in 2026 for this patent number, and no live USPTO proceeding. I searched for it directly and returned only unrelated hits (e.g., a Brazilian TRF-3 appeal numbered 5023269-94.2019, and JP 5023269 B2, a Japanese surfactant patent — different jurisdictions/subject matter, not the same patent). Treat the "no 2026 CAFC activity" finding as a reasonable negative result, not a certainty.

Bibliographic data (per the patent front page)

Abstract (verbatim)

"The present invention provides 3-aryloxy-3-substituted propanamines capable of inhibiting the uptake of serotonin and norepinephrine."

Commercial significance

This is the duloxetine compound patent — the active ingredient in Lilly's Cymbalta® (duloxetine hydrochloride). Duloxetine is named in the disclosure/examples as N-methyl-3-(1-naphthalenyloxy)-3-(2-thienyl)propanamine. It is described as a dual serotonin/norepinephrine reuptake inhibitor (SNRI), in contrast to the specification's discussion of fluoxetine (selective serotonin) and tomoxetine (selective norepinephrine) from U.S. Pat. Nos. 4,018,895, 4,194,009 and 4,314,081.

Plain-language overview of the independent claims

The Google Patents text I retrieved contains the full specification but the verbatim claim set was truncated, so I give the substance of the independent claims as they are framed in the "Summary of the Invention," with the caveat that the exact claim wording is not reproduced here.

1. Compound claim (the genus claim). A 3-aryloxy-3-substituted propanamine of the formula shown as ##STR1## — i.e., a propanamine chain bearing (a) an aryloxy group (Ar-O-) at the 3-position of the chain, and (b) a substituent R¹ at that same 3-position. In plain terms:

• R¹ is C₅–C₇ cycloalkyl, thienyl, halothienyl, (C₁–C₄ alkyl)thienyl, furanyl, pyridyl or thiazolyl;
• the aryl portion (##STR2##) is a naphthalenyl-type ring system optionally substituted with one or two R⁴ groups (each independently halo, C₁–C₄ alkyl, C₁–C₃ alkoxy or trifluoromethyl; m = 0, 1 or 2) and optionally one R⁵ (halo, C₁–C₄ alkyl or trifluoromethyl; n = 0 or 1);
• R² and R³ are each independently hydrogen or methyl (i.e., the terminal amine is either –NHCH₃, –N(CH₃)₂, or –NH₂), and
• the pharmaceutically acceptable acid addition salts thereof (e.g., hydrochloride, oxalate, maleate).

The specification expressly includes the dl-racemates as well as the individual d- and l- enantiomers, since the carbon labeled "C" is asymmetric.

Minor uncertainty: the OCR rendering of the Markush fragment ##STR2## is ambiguous about exact ring positions of R⁴/R⁵ on the naphthalene, though the enumerated species (1-naphthalenyloxy, 2-naphthalenyloxy, 4-methyl-1-naphthalenyloxy, 4-chloro-, 4-trifluoromethyl-, 6-iodo-, 5-methyl-2-naphthalenyloxy, etc.) make the intent clear.

2. Pharmaceutical formulation claim. A pharmaceutical formulation (composition) comprising a compound of the above genus together with a pharmaceutically acceptable carrier, diluent or excipient. The specification describes unit dosage forms containing about 5–500 mg (more usually 25–300 mg) of active ingredient, as tablets, capsules, syrups, suppositories, aerosols, injectables, etc.

3. Method-of-use claims. Methods for inhibiting serotonin uptake and for inhibiting norepinephrine uptake in a mammal, comprising administering a pharmaceutically effective amount of a compound of the genus — i.e., the dual-uptake-inhibition utility. Related method claims cover treating disorders linked to decreased serotonergic/noradrenergic neurotransmission: obesity, depression, alcoholism, pain, loss of memory, anxiety and smoking. Typical recited daily dose ranges are about 0.01–20 mg/kg (preferably 0.05–10 mg/kg).

The DrugPatentWatch entry characterizes the patent's claim types as Compound; Use; Composition, consistent with the three groups above. I could not independently confirm the total claim count or the exact language of claims 2–16 from an authoritative source in this session.

Litigation note (for completeness)

Google Patents lists numerous 2008–2009 district court cases (S.D. Ind. and D.N.J.) involving this patent and the Lilly v. Lupin family of suits (see the Unified Patents litigation links and the Stanford NPE database entry, e.g. Eli Lilly and Company v. Lupin Limited et al., 1:08-cv-01596, S.D. Ind.). The patent expired in 2013, so any 2026 appellate activity would be unusual, and my searches surfaced none.

I'll search litigation databases for this specific patent number.

Let me gather details on each specific case.

Let me get details on the New Jersey cases, the appellate activity, and any post-grant challenges.

Caveat on scope of the search

I was able to pull the litigation records tied to US 5,023,269 from the Stanford NPE Litigation Database, the Unified Patents litigation links surfaced on the Google Patents front page, the Finnegan (Lilly's outside counsel) press release, Lilly's own investor communications, and the Cymbalta consent-order PDF hosted on PatentDocs. My last query (looking specifically for any IPR/PGR/post-grant challenge) was cut off by a step limit, so treat the "no post-grant proceeding" statement below as unverified. I found no 2026 litigation or appellate activity — not surprising for a patent that expired in 2013.

Important framing note: Every case I could confirm was a Hatch-Waxman ANDA case in which Eli Lilly and Company was the sole plaintiff. Lilly is a practicing entity, not an NPE — the Stanford database classifies it as a "Product company" (Asserter Category 8).

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Confirmed litigation involving US 5,023,269

The core Cymbalta / duloxetine HCl ANDA litigation (2008–2011)

Defendants named in press reporting as having been sued on the '269 patent (nine generic manufacturers in 2008):

• Wockhardt Limited / Wockhardt USA
• Lupin Limited / Lupin Pharmaceuticals, Inc.
• Aurobindo Pharma Ltd. / Aurobindo Pharma USA, Inc.
• Sun Pharmaceutical Industries Ltd.
• Sandoz, Inc.
• Cobalt Laboratories
• Impax Laboratories, Inc.
• Actavis Elizabeth LLC
• (plus one further filer — the ninth — not identified in the sources I retrieved)

Individual S.D. Ind. docket numbers listed on the Google Patents litigation record for this patent:

Filing dates confirmed by contemporaneous reporting:

• November 24, 2008 — Lilly petition filed against Lupin and Aurobindo (per The Hindu summary reprinted on PatentColumn, filed "before US District Court for the Southern Districts of Indiana")
• November 18, 2008 — Impax Laboratories announced Lilly had sued it in S.D. Ind. based on Impax's ANDA (submitted August 4, 2008)
• December 4, 2008 — Eli Lilly and Company v. Sun Pharmaceutical Industries Ltd. et al., 1:08-cv-01629

The D.N.J. cases

The Google Patents record also lists eight District of New Jersey filings tied to this patent's family:

⚠️ Contradiction/uncertainty flag: I want to be explicit that I could not confirm the party names or dispositions for the eight D.N.J. dockets. Google Patents presents them as family-level litigation data (its Darts-ip link is labeled "First worldwide family litigation"), so some of these may relate to sibling patents in the same family (e.g., the EP 273658 counterpart or the '388 patent) rather than the '269 patent itself. I also encountered a D.N.J. docket — Eli Lilly and Company v. Actavis Elizabeth LLC, 2:07-cv-03770 (D.N.J., Judge Dennis M. Cavanaugh) — that involves a '590 patent and atomoxetine (Strattera), not the '269 patent. Do not conflate that case with the Cymbalta matters; the similarly-named defendants (Sandoz, Mylan, Apotex, Aurobindo, Sun) make the two lines of cases easy to mix up.

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What I did NOT find

• No Federal Circuit appeal of the '269 case. The Finnegan release and Lilly's April 27, 2011 press release both indicate the remaining cases ended by stipulated dismissal, and Lilly stated expressly that "the litigation has been dismissed and no appeal is possible." The CAFC activity I did surface around this era relates to other Lilly patents (the atomoxetine/Strattera '590 patent appeal in D.N.J.; the Evista/raloxifene particle-size appeal in S.D. Ind.; Eli Lilly v. Medtronic, 872 F.2d 402 (Fed. Cir. 1989)), not to US 5,023,269.
• No 2026 docket activity of any kind — consistent with the patent's expiration (June 11, 2013, adjusted/with pediatric exclusivity to Dec. 11, 2013).
• No IPR/PGR/reexamination confirmed. Caveat: my search for post-grant proceedings was truncated, so I cannot affirmatively rule out an IPR or inter partes reexamination. Given that the district court litigation resolved in 2011 and IPR practice began in September 2012 (by which time the patent had ~9 months of term left), a post-grant challenge would be improbable but I did not prove the negative.
• No ITC Section 337 action, no antitrust/counterclaim case, and no declaratory-judgment action (the Stanford database entry records "Declaratory Judgment: No").
• A non-litigation note: In 2009, Article One Partners ran a crowdsourced prior-art search aimed at invalidating the '269 patent in connection with the Cymbalta dispute and paid a $50,000 award. This was a prior-art research bounty, not litigation.

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Summary table of resolved outcomes

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Sources

• Stanford NPE Litigation Database, patent 5023269: https://npe.law.stanford.edu/patent/5023269 ; case entry for ELI LILLY AND COMPANY v. LUPIN LIMITED et al, 1:08-cv-01596: https://npe.law.stanford.edu/case/[139834](/patent/139834)
• Finnegan, "Finnegan Client Eli Lilly and Company Prevails in U.S. Cymbalta® Litigation," April 28, 2011: https://www.finnegan.com/en/firm/news/finnegan-client-eli-lilly-and-company-prevails-in-u-s-cymbalta.html
• Eli Lilly & Co. press release, "U.S. District Court Order Maintains Patent Exclusivity for Lilly's Cymbalta," April 27, 2011: https://investor.lilly.com/static-files/51c7970b-a920-405c-b507-79f9ffd130b8
• Eli Lilly and Company v. Actavis Elizabeth LLC, Order and Stipulation of Dismissal, S.D. Ind. No. 1:08-cv-1547: https://patentdocs.typepad.com/files/cymbalta.pdf
• PatentDocs, "Court Report," Dec. 7, 2008 (Sun/1:08-cv-01629 filing description): https://patentdocs.org/2008/12/07/court-report-27/
• Impax Laboratories news release, Nov. 18, 2008 ("Impax Sued Based on ANDA for Generic Cymbalta"): https://salesandmarketing.network/news_release_bs.html?pipe=0000ac177000191&ID=[2026596](/patent/2026596)
• PatentColumn, "Eli Lilly files suit against Lupin, Aurobindo in US," Dec. 3, 2008 (reprinting The Hindu): http://patentcolumn.blogspot.com/2008/12/eli-lilly-files-suit-against-lupin.html
• iniplaw.org summary of the S.D. Ind. order (case number 1:08-cv-1547-TWP-TAB; identifies Judge Tanya Walton Pratt): https://www.iniplaw.org/eli-lilly-co-wins-court-ruling/
• IPBiz, Sept. 21, 2009 (Article One Partners prior-art bounty re the '269 patent): http://ipbiz.blogspot.com/2009/09/article-one-makes-more-awards.html
• Google Patents front page, US5023269A (Unified Patents and Darts-ip litigation links): https://patents.google.com/patent/US5023269/en

Bottom line: The only litigation I can substantiate against US 5,023,269 is the 2008–2011 Lilly Hatch-Waxman campaign in the Southern District of Indiana against roughly nine generic duloxetine HCl ANDA filers, which Lilly won by a March 21, 2011 final judgment against Wockhardt on claims 10 and 11 and an April 27, 2011 consent order against the remaining defendants. It ended by stipulated dismissal with no appeal. The eight D.N.J. docket numbers on the patent's Google Patents page are listed without party names and I could not verify them; treat those as unconfirmed.

I'll verify the structured block's "no proceedings" result against the public record before writing.

Let me run a few more targeted checks on PTAB dockets, reexaminations, and any AIA-trial activity.

Proceedings overview

Zero AIA trial proceedings have been filed on US 5,023,269: the canonical USPTO Open Data Portal list in the structured block returns no IPR, PGR, or CBM (0 active / 0 claims invalidated / 0 claims sustained / 0 settled / 0 institution denials), and independent web checks against PTAB decision databases and litigation reporters surfaced no petition, no Final Written Decision, and no Federal Circuit appeal of any PTAB decision on this patent. The defensive posture is therefore not "the patent survived IPRs and is hardened," and also not "the claims are dead on the merits" — it is: the patent is expired, its validity was adjudicated in district court rather than at the PTAB, and there is no AIA record at all. That absence is a timing artifact, not a signal about claim strength (explained below).

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Proceedings on file

None. There are no proceeding numbers to report, and I will not manufacture any. The per-proceeding template (petition grounds, institution decision, FWD, settlement, appeal) is inapplicable because no trial was ever instituted.

Why there are zero AIA proceedings — the timing explanation

This is the analytically important point, because a naive reading of "no IPRs" would suggest the patent was never seriously challenged. It was seriously challenged — just in the wrong forum era:

Sources: Google Patents litigation block (https://patents.google.com/patent/US5023269/en) listing the S.D. Ind. cases (1:08-cv-01547, -01548, -01549, -01550, -01559, -01595, -01596, -01629; 1:09-cv-01029) and D.N.J. cases (3:08-cv-06124, -06135, -06136, -06137, -06138, -06139, -06261, -06266); Finnegan client note (https://www.finnegan.com/zh-CHT/firm/news/finnegan-client-eli-lilly-and-company-prevails-in-u-s-cymbalta.html); Lilly press release (https://investor.lilly.com/static-files/51c7970b-a920-405c-b507-79f9ffd130b8); Actavis stipulation/order (https://patentdocs.typepad.com/files/cymbalta.pdf).

The generics' invalidity (obviousness) theories — including the Molloy et al. prior-art compounds and the argument that Cymbalta's success flowed from the enteric coating rather than the '269 claims, raised in the Wockhardt discovery dispute — were litigated in S.D. Ind., not at the Board. No IPR ever re-tested those grounds. So there is no FWD to link to, and no § 315(e)(2) estoppel was ever created because no IPR was instituted.

Confidence note: the "zero proceedings" finding rests on (a) the USPTO ODP structured block (authoritative for AIA trials) and (b) multiple targeted web searches that returned only unrelated IPR numbers (e.g., IPR2017-00693, IPR2017-00316 — different patents/parties) and no '269 petition. I found no public evidence of an ex parte reexamination either, but ODP's AIA-trial feed would not capture reexaminations, so treat that as unverified rather than established.

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Strategic summary

Claim status: neither canceled nor PTAB-sustained — court-validated and now expired. No claim of US 5,023,269 was ever canceled, disclaimed, or amended through an AIA trial, because no trial occurred. The only adjudicated claim-level outcome of record is the 2011-03-21 S.D. Ind. Final Judgment against Wockhardt, reported by Finnegan as finding that Wockhardt's generic duloxetine HCl products infringe asserted claims 10 and 11 and confirming the validity and enforceability of the '269 patent. Claims other than 10 and 11 were not the subject of a merits validity ruling that I can verify — do not assume they were tested. My earlier summary flagged that I could not confirm the total claim count or the verbatim text of claims 2–16; that gap is unresolved and matters if anyone quotes a specific claim number.

Estoppel landscape: essentially empty, but also irrelevant. Because no IPR/PGR was instituted, there is no § 315(e)(2) estoppel barring any petitioner or privy from raising any ground — the entire prior-art universe (Molloy et al., the fluoxetine/tomoxetine patents cited at 4,018,895 / 4,194,009 / 4,314,081, and anything else) remains formally un-estopped as a PTAB matter. But that is a theoretical benefit: a defendant cannot file an IPR to knock out an expired patent's claims in a way that buys commercial freedom, and the practical exit is § 286's six-year damages lookback, which ran out on approximately 2019-06-11 (or 2019-12-11 counting pediatric exclusivity). Any demand letter citing this patent in 2026 is asserting rights against conduct that is now time-barred.

Pattern signals: no petitioner repeats, no PO appeals, no defensive aggregator. There is no multiple-petition pattern, no patent-owner appeal history (as a report states, "no appeal is possible" following the stipulated dismissal), and no Unified Patents or other aggregator in the chain. The only recurring actor is Eli Lilly as plaintiff enforcing the '269 patent against nine generic filers in 2008–2011.

One contradiction to flag for the record: my previously generated summary characterized the patent's listed legal status as "Expired – Lifetime" with adjusted expiration 2013-06-11. That is consistent with everything found here. However, a search result from DrugPatentWatch's generic Cymbalta market page loosely refers to "early invalidation or non-infringement rulings" affecting Cymbalta patents; in context that passage concerns a different, later patent (it names U.S. 7,553,847). It does not describe any invalidation of the '269 patent, and the 2011 S.D. Ind. judgment went the other way. Do not cite that page as evidence of '269 invalidity.

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Recommended next steps

1. If you are a defendant or accused infringer: the correct response to any modern '269 assertion is not an IPR petition but a statute-of-limitations and standing analysis. State plainly that no AIA trial proceeding has ever been filed against US 5,023,269, that the patent expired (adjusted expiration 2013-06-11, with pediatric exclusivity to 2013-12-11), and that any pre-expiration damages claim is now outside the § 286 six-year window. There is no FWD to link to — say that rather than citing a nonexistent one.
2. If you need the claim text before relying on any claim number: the verbatim claim set was truncated in the Google Patents extract used for this analysis, and the only claim numbers I can confirm from a public source are 10 and 11 (asserted and adjudged infringed against Wockhardt). Pull the issued patent PDF from USPTO PatentCenter or the Google Patents PDF (https://patents.google.com/patent/US5023269/en) to confirm claims 1–16 verbatim before quoting them.
3. If you are researching the family: the more productive PTAB targets are the later duloxetine patents (e.g., the polymorph/process family around U.S. 7,553,847, and the '269 division/continuation relatives U.S. 4,956,388, 5,362,886 and 5,491,243), where AIA-era challenges would have been possible. None of those is the subject of this report; each needs its own ODP pull.
4. If you are checking for 2026 activity: I found none. No PTAB trial, no CAFC appeal of a PTAB decision, no live proceeding. Thirteen years past expiration, further AIA activity on this patent would be anomalous, and a negative finding here should be treated as reliable for PTAB purposes.

I'll research the assignment record for this patent. Let me run several searches in parallel.

Let me search for the specific assignment records and any post-issuance transfers.

I was unable to pull live USPTO Assignment Center records in this session (the search budget was exhausted before I could reach the assignment API/UI, and no web result surfaced a reel/frame for this patent). I will not fabricate reel/frame numbers. Below I report what the authoritative record (Google Patents legal events, as supplied) actually shows, and flag the gaps.

Inventors

Pattern note: All three inventors are Lilly employees and all list Lilly's home city (Indianapolis and the adjacent suburb of Greenwood). There is no pattern of inventors departing the assignee within 12 months of filing — the opposite is true. Wong in particular continued to publish the pharmacology of these compounds under Lilly auspices (e.g., D. T. Wong et al., Neuropsychopharmacology 8, 23 (1993)), and the same inventive team signed the parent filings in the chain (Ser. No. 06/945,122 → 07/462,925 → 07/499,940). This is a classic in-house, vertically integrated pharma invention record — not a precursor to a portfolio fire-sale.

Caveat: I could not independently verify execution dates on a signed inventor→Lilly assignment instrument (see Assignment timeline).

Original assignee

Eli Lilly and Company (Indianapolis, Indiana) is the assignee named on the issued patent and the "Original Assignee" of record per the patent front page; the Google Patents legal-events feed likewise lists "Application filed by Eli Lilly and Co" on 1990-03-27.

• Product embodying the claims: Yes — Cymbalta® (duloxetine hydrochloride), the SNRI whose active ingredient is N-methyl-3-(1-naphthalenyloxy)-3-(2-thienyl)propanamine, expressly within the genus and Example set. Lilly's own April 2011 press materials describe the '269 patent as "covering duloxetine hydrochloride, the active ingredient in Cymbalta®," and the Wockhardt judgment found generics infringed asserted claims 10 and 11.
• Primary line of business: Research-based global pharmaceutical manufacturer. Cymbalta was Lilly's second-best-selling drug (~$3.3 billion worldwide in 2010).
• Current status (2026): Operating company; no bankruptcy, no dissolution, no acquisition. The patent itself expired 2013 (adjusted expiration 2013-06-11, extended to 2013-12-11 under pediatric exclusivity), and Lilly's product exclusivity ended at that point.

Assignment timeline

This is the key finding: the Google Patents legal-events record for US 5,023,269 contains no assignment, change-of-name, merger, security-interest, or release events at all. The only recorded events are prosecution and term events:

• 1986-12-22 — priority/earliest filing (Ser. No. 06/945,122, now abandoned)
• 1990-01-12 — Ser. No. 07/462,925 filed (now US 4,956,388)
• 1990-03-27 — Application 07/499,940 filed by Eli Lilly and Co; priority to US07/499,940
• 1991-06-11 — Application granted; publication of US5023269A
• 2013-06-11 — Adjusted expiration (Expired – Lifetime)

No post-issuance transfer is recorded anywhere I could reach. In particular:

• No assignment/transfer to any "IP Holdings," "Licensing," "Ventures," or other LLC.
• No security agreement, no release, no merger, no change of name.
• No transfer to, or from, RPX / AST / Unified Patents / LOT / OIN.

I was unable to retrieve a reel/frame for the underlying inventor→Lilly assignment, and I will not invent one. Two possibilities remain and I cannot distinguish them on the available data: (a) an inventor→Lilly assignment was recorded on filing and simply is not reflected in the Google Patents events feed, or (b) it was never separately recorded because Lilly took the application by the inventors' employment/assignment obligation and prosecuted in its own name. Either way, the ownership that matters — the assignee of record at issue and throughout the patent's life — is Eli Lilly and Company, and it never changed.

Do not treat the absence of an assignment event as a gap in my data that a below-verdict inference can fill. The patent was enforced by Lilly as record owner, suing in its own name (see below), which is inconsistent with any transfer of title away from Lilly during the 2008–2011 litigation window.

Timeline diagram

timeline
    title Ownership of US 5023269
    1986 : Priority filing by inventors
    1990 : Division filed by Eli Lilly and Co
    1991 : Patent issued to Eli Lilly and Co
    2008 : Lilly sues generics as record owner
    2011 : Judgment against Wockhardt
    2013 : Patent expires

NPE / troll-pattern signals

1. Shell-entity transfer — NOT PRESENT. No recorded conveyance to any licensing-only LLC. The assignee of record is Eli Lilly and Company; there is no "IP / Holdings / Licensing / Ventures" transferee anywhere in the record I could reach.
2. Known asserter in the chain — NOT PRESENT. The only asserter is Eli Lilly, an operating pharmaceutical manufacturer. The Stanford NPE Litigation Database classifies the Eli Lilly and Company v. Lupin matter (1:08-cv-01596, S.D. Ind.) with the asserter category "Product company," not as an NPE/PAE. No entity from the Acacia / Marathon / IV / IPNav / Wi-LAN / Conversant / Vringo / Pendrell / MPHJ / Lumen View / Round Rock / Erich Spangenberg lists appears.
3. Repeat correspondent across the chain — NOT PRESENT / INSUFFICIENT DATA. I could not retrieve USPTO correspondent-of-record data for this patent in this session, so I cannot affirm or negate a repeat recording attorney. This is a data gap, not a clean negative. (For context, Lilly's litigation counsel was Finnegan, Henderson, Farabow, Garrett & Dunner — a general-practice firm that does both operating-company and defense work — but litigation counsel is not the assignment-recording correspondent and its single appearance is not a signal under this factor.)
4. Cascading transfers — NOT PRESENT. Zero consecutive assignments through chained LLCs; the ownership chain is a straight line from inventors to Eli Lilly, unchanged for the patent's life.
5. Pre-litigation transfer — NOT PRESENT. The first suits naming the '269 patent were filed in late 2008 (e.g., 1:08-cv-01547 through 1:08-cv-01629, S.D. Ind.). Lilly was the plaintiff of record, so there was no assignment "arranged to enable assertion" within six months of filing.
6. Bankruptcy fire-sale — NOT PRESENT. Lilly never filed Chapter 7/11; no assets were sold in proceedings.
7. Privateering — NOT PRESENT. Lilly asserted the patent itself against generic ANDA filers who were competitors in the U.S. duloxetine market; there is no operating-company-to-NPE transfer and no NPE asserting on Lilly's behalf.
8. Defensive aggregator — NOT PRESENT. The chain never terminates at RPX, AST, LOT, Unified Patents, or OIN; the patent simply expired in Lilly's hands in 2013.

Verdict

Operating-company assertion.

Justification: The assignee of record and the litigation plaintiff are the same entity — Eli Lilly and Company — which both shipped a product embodying the claims (Cymbalta/duloxetine HCl, ~$3.3 billion in 2010 sales) and sued actual competitors (nine generic ANDA filers in S.D. Ind., 2008–2011), winning a March 21, 2011 judgment that Wockhardt's generics infringed claims 10 and 11. Google Patents' legal-events record shows no assignment, change-of-name, merger, security, or release event at any point, and the Stanford NPE Litigation Database categorizes the asserter as a "Product company." There is no shell LLC, no known asserter, no cascading transfer, and no defensive-aggregator terminus — the ownership story is the reverse of an NPE pattern.

Two honest caveats:

• I could not retrieve live Assignment Center records or a reel/frame in this session; my "no post-issuance assignment" finding rests on the Google Patents legal-events feed supplied as authoritative, plus the corroborating fact that Lilly litigated as record owner. Verify independently at the USPTO Assignment Center search page: https://assignmentcenter.uspto.gov/ (search by patent number 5023269; note the legacy assignment.uspto.gov / assignments.uspto.gov URLs are being retired, per USPTO's Feb 2, 2026 notice).
• The inventor→Lilly assignment instrument, if separately recorded, is the one link I could not document; a reel/frame for it should be confirmed directly rather than assumed.

I'll research the cited prior art for US 5,023,269.

Let me find the actual "References Cited" section on the patent front page.

Let me try to retrieve the patent front page (citation list) directly.

Retrieval status and a required caveat (read first)

What I could verify in this session. The authoritative full text you supplied (Google Patents, fetched 2026‑10‑01) covers the specification, abstract, classification, and bibliographic data for US 5,023,269 A. It does not include the front‑page "References Cited" table (patent citations). My searches returned the patent's own full text, family/modeling patent documents that cite it, litigation links, and Orange Book/DrugPatentWatch entries — but not the examiner's/author's citation list printed on the '269 front page.

I must be explicit about this per the operating rules: I could not retrieve the verbatim "References Cited" (PTO‑892 / front‑page) list for US 5,023,269 in this session, and my search budget is now exhausted. Everything below is therefore split into (a) citations I can verify from the patent's own authoritative text, (b) family documents, and (c) my prior-art analysis. Where a date or content is from my training knowledge rather than a retrieved source, I mark it unverified.

How to get the definitive list (so this answer can be closed out): USPTO Patent Center file wrapper for application 07/499,940 (all "References Cited" / PTO‑892 forms); the "Patent Citations" tab on the Google Patents page (present in the HTML but not in the fetched text I received); or the scanned front page of the patent PDF.

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1. Patent-grant date anchors relevant to § 102 (this is a pre‑AIA patent)

Because pre‑AIA 35 U.S.C. § 102 governs, anything patented or described in a printed publication before Dec. 22, 1985 is § 102(b) art; anything published between Dec. 22, 1985 and Dec. 22, 1986 is § 102(a) art only (and can be sworn behind); and co‑invented/commonly‑owned family members are not § 102(e) art ("by another" is not met).

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2. Prior art cited in the patent's own text (verified from the authoritative full text)

The only U.S. patents the '269 specification names are in the Background section:

"…the hydrochloride salt of fluoxetine (dl‑N‑methyl‑γ‑[4‑(trifluoromethyl)phenoxy]benzenepropanamine) is a selective serotonin … uptake inhibitor … Similarly, tomoxetine hydrochloride ((−)‑N‑methyl‑δ‑(2‑methylphenoxy)benzenepropanamine hydrochloride) is a selective inhibitor of norepinephrine uptake … These compounds are among many taught in U.S. Pat. Nos. 4,018,895, 4,194,009, and 4,314,081 as being potent but selective blockers of the uptake of a particular monoamine."

Bottom line on A/B/C: none anticipates any claim of US 5,023,269. They are the closest prior art of record and are § 102(b)/§ 103‑type references, not § 102‑anticipatory references. The distinguishing limitation is the R¹ heteroaryl/cycloalkyl substituent and the naphthalenyl (Ar) oxy group in the claim‑1 genus.

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3. Family documents — expressly not § 102 prior art

(Cross‑reference: the earlier‑generated summary's characterization of 4,956,388 as the parent, and of EP 273658 as the counterpart, is consistent with the authoritative '269 text — no contradiction.)

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4. Verified — how later patents treat the '269 art family

These confirm A/B/C as the recognized prior‑art cluster for this subject matter, and are useful as a proxy for what the examiner of 07/499,940 searched:

• EP 1 379 492 B1, "Patent documents cited in the description": US 4018895 A; US 4194009 A; US 4314081 A; US 4956388 A; US 5023269 A — i.e., exactly patents A, B, C plus the '388/'269 family.
• EP 1 857 435 A2, "Patent documents cited in the description": US 5023269 A; US 5362886 A; EP 457559 A; US 4018895 A; EP 52492 A.
• US 8,093,407 / US 2008/0021089, "Referenced Cited": US 4,956,388 (Sept. 11, 1990, Robertson et al.) and US 5,023,269 (June 11, 1991, Robertson et al.), plus US 5,362,886 and US 5,491,243 (Berglund) — the '269 document is now itself cited as prior art for later duloxetine‑synthesis patents.
• WO 2011/145102 describes US5023269 as disclosing preparation of racemic duloxetine via demethylation of the N,N‑dimethyl propanamine with phenyl chloroformate — relevant only if a claim is directed to that process, in which case later patents (e.g., US 5,362,886, US 5,491,243) are the § 102(b)/§ 103 art, not the reverse.

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5. Direct answers to the task

1. "Search USPTO for 5023269." The record I can rely on is the Google Patents text of US 5,023,269 A, appl. 07/499,940, filed Mar. 27, 1990, granted June 11, 1991, priority Dec. 22, 1986, assignee Eli Lilly and Company, inventors Robertson, Wong, Krushinski. I was unable to open the USPTO Patent Center front page / file wrapper for this application in this session; that is the only place the complete examiner‑cited reference list is authoritative. Note also the unrelated JP 5023269 B2 (a Japanese surfactant/coating patent, Sun Nopro, 2012) — a different document entirely; do not conflate it with US 5,023,269.

2. Most relevant prior art for US 5,023,269: US 4,018,895; US 4,194,009; and US 4,314,081 (all Eli Lilly aryloxy‑propanamine patents, all § 102(b) art). This set is: (i) the only patent art the '269 specification itself names; and (ii) independently corroborated as the cited art family in the "Patent documents cited in the description" lists of EP 1 379 492 B1 and EP 1 857 435 A2 and in the "Referenced Cited" lists of US 8,093,407 / US 2008/0021089.

3. Which claims they potentially anticipate under § 102: none. For each of US 4,018,895, US 4,194,009, and US 4,314,081:

   • They are § 102(b) references by date (all published well before Dec. 22, 1985), but
   • they do not disclose a 3‑position substituent falling within R¹ = C₅–C₇ cycloalkyl, thienyl, halothienyl, (C₁–C₄ alkyl)thienyl, furanyl, pyridyl or thiazolyl, and
   • they do not disclose the naphthalenyloxy Ar moiety that appears in the species of the '269 disclosure (1‑naphthalenyloxy, 2‑naphthalenyloxy, 4‑methyl‑1‑naphthalenyloxy, 4‑chloro‑, 4‑trifluoromethyl‑, 6‑iodo‑, 5‑methyl‑2‑naphthalenyloxy, etc.), all of which are benzene‑based (phenoxy/2‑methylphenoxy) in the fluoxetine/tomoxetine art.

   Consequently, if any claim of '269 were invalidated on this art, the theory would be § 103 obviousness (single‑monoamine‑selective aryloxypropanamines + a known heteroaryl/cycloalkyl pharmacophore swap + naphthalenyloxy homologation), not § 102 anticipation. No claim of the '269 patent — genus (claim 1‑type), the species claims covering N‑methyl‑3‑(1‑naphthalenyloxy)‑3‑(2‑thienyl)propanamine (duloxetine), the N,N‑dimethyl homolog, the formulation claims, or the serotonin/norepinephrine‑uptake method claims — is anticipated by A, B, or C.

Flagged uncertainty (do not treat as settled): (i) I could not read the verbatim claim set of '269, so I refer to claims by group (genus / species / formulation / method) rather than by number; (ii) I could not retrieve the front‑page "References Cited" list, so additional examiner‑cited patents (e.g., further foreign patents or NPL) may exist that I have not reported — I am deliberately not fabricating any citation numbers; (iii) the issuance dates for US 4,018,895 and US 4,194,009 given above are from my prior knowledge and were not verified against a primary source in this session.

I'll research the prior art relevant to this patent before building the §103 analysis.

Key prior art is emerging. Let me dig deeper into the specific references cited and the thienyl prior art.

Let me pin down the exact claims, the cited references on the patent face, and the Lilly v. Wockhardt validity opinion.

Obviousness Analysis — U.S. Patent 5,023,269 under 35 U.S.C. § 103

Bottom line up front: The '269 claims sit one structural step away from an admitted, same-assignee prior-art genus that already disclosed (i) the identical propanamine backbone, (ii) the identical 1‑naphthalenyloxy group, (iii) the identical N‑methyl/N,N‑dimethyl amine options, (iv) the identical salt list, and (v) the identical antidepressant/monoamine-uptake utility. The only element of claim 1 not literally disclosed is R¹ = heteroaryl/cycloalkyl at the 3-position — i.e., the substitution of a 2-thienyl for the prior art's phenyl. That single change is the entire § 103 battleground, and it is a textbook bioisosteric swap. A prima facie obviousness case is therefore strong for most claims, but the patentee has a real (and, as litigated, successful) rebuttal in the form of unexpectedly dual 5‑HT/NE activity.

I flag at the outset that I hit the tool-step limit, so this is built on the references I did retrieve — most importantly the Lilly/Molloy–Schmiegel family and the published Cymbalta litigation record.

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1. The claims at issue

Per the previously generated summary, the '269 claim set comprises: (1) a genus compound claim (3-aryloxy-3-substituted propanamines), (2) formulation claims, and (3) method-of-use claims (inhibiting serotonin uptake; inhibiting norepinephrine uptake; treating obesity, depression, alcoholism, pain, memory loss, anxiety, smoking). DrugPatentWatch characterizes the claim types as "Compound; Use; Composition" (drugpatentwatch.com/p/patent/5023269).

Critically for the analysis: claim 1's R¹ is not phenyl. It is limited to C₅–C₇ cycloalkyl, thienyl, halothienyl, (C₁–C₄ alkyl)thienyl, furanyl, pyridyl or thiazolyl. So the prior-art 3-phenyl compounds are outside claim 1 — the whole obviousness question is whether the phenyl → 2-thienyl replacement (yielding duloxetine) was obvious.

Unverified point: I could not retrieve the verbatim claim set in this session. The Finnegan report on the Cymbalta litigation states that claims 10 and 11 were the asserted claims against Wockhardt (finnegan.com). Given the specification's working examples (Example 1 → N,N‑dimethyl‑3‑(1‑naphthalenyloxy)‑3‑(2‑thienyl)propanamine; Example 2 → the N‑methyl compound; plus "(+)-N-methyl-3-(1-naphthalenyloxy)-3-(2-thienyl)propanamine maleate, mp 118°–122° C." and the oxalate, mp 133°–134° C.), claims 10/11 most plausibly recite the duloxetine species and/or a specific salt or enantiomer thereof. Treat that as inference, not fact.

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2. Prior art on the record

2.1 Prior art admitted in the '269 specification itself (AAPA)

The '269 Background states that fluoxetine ("dl‑N‑methyl‑γ‑[4‑(trifluoromethyl)phenoxy]benzenepropanamine") and tomoxetine ("(-)‑N‑methyl‑δ‑(2‑methylphenoxy)benzenepropanamine") "are among many taught in U.S. Pat. Nos. 4,018,895, 4,194,009, and 4,314,081 as being potent but selective blockers of the uptake of a particular monoamine."

That sentence is an admission that the prior art taught the same scaffold as potent monoamine-uptake blockers.

2.2 U.S. 4,018,895 — Molloy & Schmiegel (Lilly), "Aryloxyphenylpropylamines in treating depression"

Sources: patents.google.com/patent/US4018895; drugpatentwatch.com/p/patent-claims/4018895.

2.3 U.S. 4,313,896 — "Aryloxyphenylpropylamines" (same 432,379 grandparent)

Abstract: "3‑Aryloxy‑3‑phenylpropylamines and acid addition salts thereof, useful as psychotropic agents, particularly as anti-depressants. 4 Claims." Its Summary describes the same Markush genus — "R is naphthyl or [substituted phenyl]," "each R′ is independently hydrogen or methyl," with substantially the same R″/R‴ definitions, and "n and m are 0, 1 or 2; and acid addition salts thereof." Its background expressly states: "Two U.S. Pat. Nos. 4,018,895 and 4,194,009, based on divisional applications identical in disclosure to Ser. No. 432,379, have issued."

Sources: US4313896 PDF; patents.justia.com/patent/4313896.

2.4 U.S. 4,314,081 and U.S. 4,584,404 — the N‑methyl / SAR references

U.S. 4,584,404's background (a Lilly/Molloy–Schmiegel family member) recites that "the claims of U.S. Pat. No. 4,314,081 cover secondary amines of the formula R‑O‑CH(R′)–CH₂–CH₂–NH–CH₃ wherein R′ has its previous scope but R is m‑ or p‑chlorophenyl, o, m or p‑anisyl, phenyl, o- or m‑fluorophenyl, o- or p‑tolyl, 2,4‑difluorophenyl or p‑trifluoromethylphenyl. These claimed secondary amines each had unusually high activity in inhibiting uptake of serotonin (5HT) and norepinephrine (NE) with less effect on dopamine uptake."

It further explains that fluoxetine's 5‑HT/NE IC₅₀ ratio was "0.06 to 20 or about 333 to 1," that "[t]wo of these [clinical candidates] have been primarily NE uptake inhibitors," and that "it is the purpose of this application to specify and claim these drugs" — i.e., compounds of the same scaffold deliberately selected for very high or very low 5‑HT/NE ratios.

Source: US4584404 PDF.

2.5 Older art establishing the scaffold

• U.S. 3,106,564 — tertiary 2-phenoxy-2-phenylethylamines as CNS agents.
• J. Pharm. Soc. Japan 93, 508–519, 1144–53, 1154–61 (1973) — several tertiary 3-phenoxy-3-phenylpropylamines as mydriatics.
• GB 2 060 618 A — process for "preparing a 3‑aryl‑3‑aryloxypropylamine… wherein Ar is phenyl optionally substituted by one or more halogen, trifluoromethyl, lower alkyl, lower alkoxy, nitro or amino groups," via fluoro compounds in dipolar aprotic solvents; expressly frames fluoxetine as "N-methyl-3-phenyl-3-(p-trifluoromethylphenoxy)propylamine."

Sources: US4313896 PDF; GB2060618A PDF.

Note on the "Prior Art" section of the page: the Google Patents page's extracted prior art keywords for this document are "compound, thienyl, methyl, propanamine, naphthalenyloxy" (patents.google.com/patent/US5023269/en) — i.e., the very two substituent motifs (thienyl + naphthalenyloxy) that distinguish the claimed compounds from the admitted art. That is an algorithmic association, not a legal teaching, but it accurately identifies the two-point difference.

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3. Graham factors

(a) Scope/content of the prior art. Establishes: the 3-aryloxy-3-arylpropanamine pharmacophore; naphthyloxy as a permissible aryloxy group; N‑methyl and N,N‑dimethyl amine termini; pharmaceutically acceptable acid addition salts; antidepressant utility; and inhibition of 5‑HT and NE uptake as the mechanism.

(b) Level of ordinary skill. Circa 1986: a medicinal chemist (Ph.D. or M.S.) with several years' experience in CNS/antidepressant drug discovery, familiar with the Molloy–Schmiegel family (which was Lilly's own fluoxetine/tomoxetine estate) and with standard bioisosteric replacement practice.

(c) Differences. (i) R¹ = 2‑thienyl instead of phenyl at C‑3; (ii) — flowing from (i) — the asserted dual 5‑HT/NE profile; (iii) the specific salt/enantiomer selections.

(d) Objective indicia. Commercial success of Cymbalta; the asserted unexpected dual-uptake property (see §6).

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4. Proposed § 103 combinations

Combination A — '895 (primary) + the benzene/thiophene bioisostere (secondary, as skill-in-the-art)

Mapping of claim 1:

The combination: select the '895 α-naphthoxy/N‑methyl genus member and replace the C‑3 phenyl with 2‑thienyl → N‑methyl‑3‑(1‑naphthalenyloxy)‑3‑(2‑thienyl)propanamine = duloxetine.

Why a POSA would have done it:

1. Structural near-identity. '895 already names N,N‑dimethyl‑3‑(α‑naphthoxy)‑3‑phenylpropylamine. Duloxetine differs from it by exactly one ring-atom substitution (one CH of the phenyl → S) plus removal of one N-methyl. That is about as close as a chemical obviousness case gets short of anticipation.
2. Classical bioisosterism. Thiophene is the canonical five-membered aromatic bioisostere of benzene: same ring size and aromatic character, comparable steric bulk, greater electron density and lipophilicity. Substituting a thienyl for a phenyl in a known aryl-bearing drug candidate, with the expectation of retained (and possibly improved) activity, is routine medicinal-chemistry practice.
3. Finite, predictable set. The claimed R¹ list (thienyl, halothienyl, alkylthienyl, furanyl, pyridyl, thiazolyl, cycloalkyl) is precisely the small, well-known set of aryl surrogates. Under KSR, where there is "a finite number of identified, predictable solutions," a POSA has good reason to pursue them and a reasonable expectation of success — which is the "obvious to try" branch of § 103.
4. The art itself frames the goal as dual 5‑HT/NE inhibition. '081's secondary amines "had unusually high activity in inhibiting uptake of serotonin (5HT) and norepinephrine (NE)," and '404 explains fluoxetine vs. tomoxetine in terms of the 5‑HT/NE ratio. Because the art teaches that changing the aryl/aryloxy substitution shifts the 5‑HT/NE ratio, a POSA optimizing for a balanced dual inhibitor is affirmatively directed to vary the cyclic substituents — including the C‑3 aryl group.
5. Same assignee, same family, mutually consistent disclosures. '895, '009, '896, '081 and '404 share the 432,379 grandparent and issue from the same inventive entity; combining them raises no de facto "disparate references" concern and requires no leap between fields.

Combination B — Combination A + '081 (to reach the N‑methyl embodiments)

'081 claims the secondary amines R‑O‑CH(R′)CH₂CH₂‑NH‑CH₃ and is expressly characterized in the '404 background as conferring "unusually high activity in inhibiting uptake of serotonin (5HT) and norepinephrine (NE)." A POSA seeking the N‑methyl terminus of claim 1 need only apply '081's N‑methyl teaching to '895's naphthyloxy genus. Rationale: same pharmacophore, same utility, and the methyl-homolog/des-methyl relationship was the family's own optimization axis.

Combination C — Combination A + '009 / '404 (formulation claims)

'009 (per the '404 and '896 backgrounds) claims "pharmaceutical formulations containing 3-substituted phenoxy-3-phenyl dimethylamines as the active ingredient." The '269 formulation claims add only a "pharmaceutically acceptable carrier, diluent or excipient" and recite conventional unit dosage forms (tablets, capsules, syrups, suppositories, aerosols, injectables) and a routine 5–500 mg dose range. Under KSR, combining a known active with a known pharmaceutically acceptable carrier in a known dosage form is the paradigm of a predictable, obvious combination.

Combination D — '895 (method claim) + '081/'404 (mechanism) → method-of-use claims

• '895 claim 1 is "a method of treating human suffering from depression which comprises administering… an effective antidepressant dose."
• '081/'404 teach that these compounds work by inhibiting 5‑HT and NE uptake.

The '269 method claims (inhibiting serotonin uptake; inhibiting norepinephrine uptake; treating depression, anxiety, obesity, smoking, etc.) are thus the inherent mechanism of the '895 genus applied to the obvious species of Combination A. That framing is supported by Eli Lilly & Co. v. Barr Labs., 251 F.3d 955 (Fed. Cir. 2001), where the court held a later claim to "blocking the uptake of serotonin by brain neurons by administering… fluoxetine hydrochloride" was not patentably distinct from the earlier claim to "treating anxiety … by administering … fluoxetine or a pharmaceutically acceptable salt thereof," because the prior art taught the salt equivalence (as discussed in Venable/PLI treatise excerpt and the litigation commentary). The same commentary records that "the judges were not persuaded by Lilly's argument that selecting fluoxetine from the large class of compounds disclosed in claim 1 of the '895 patent would not have been obvious to one of ordinary skill in the art." (Caveat: I could not verify the caption/date of that commentary in this session; treat the paraphrase as secondary-source reporting.)

Combination E — Salt and single-enantiomer claims

'895/'896 claim "acid addition salts thereof formed with pharmaceutically acceptable acids," and the '269 salt recitations (hydrochloride, oxalate, maleate, etc.) track the conventional pharmaceutically acceptable salt list essentially verbatim. Salt formation from a basic amine is routine and predictable. As for the individual enantiomers: the '269 specification itself concedes that "[s]uch optically active isomers may be prepared from their respective optically active precursors by the procedures described above, or by resolving the racemic mixtures," and names dibenzoyl‑d‑ and ‑l‑tartaric acid as useful resolving agents. Resolution of a known racemate by conventional resolving agents, absent evidence of surprising enantiomer-specific potency, is a routine expedient.

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5. Articulated motivation to combine (single-sentence statement for each)

• A: "One of skill would substitute the phenyl ring of the known 3‑(1‑naphthalenyloxy)‑3‑phenylpropanamine with the bioisosteric 2‑thienyl ring, a routine aromatic-ring substitution expected to retain antidepressant/uptake-inhibiting activity while favorably altering physicochemical and transporter-selectivity properties."
• B: "One of skill would select the N‑methyl terminus taught by '081 for the same scaffold — the family's own established optimization axis for the 5‑HT/NE uptake ratio."
• C: "One of skill would formulate the resulting active in a conventional unit dosage form with a pharmaceutically acceptable carrier, as taught by '009 and as is routine."
• D: "One of skill would recognize that the compound's antidepressant utility operates through inhibition of serotonin and norepinephrine uptake, and would therefore practice the method for that inherent purpose."

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6. Rebuttal — where the patentee wins

The obviousness case is not a foregone conclusion. The patentee's strongest positions:

1. No reference discloses a 3-heteroaryl compound, let alone 3-thienyl. Every retrieved prior-art compound is a 3-(unsubstituted, substituted or fused) carbocyclic aryl. Under In re line-of-descent-type reasoning, the entire genus claim 1 is a new genus (heteroaryl/cycloalkyl at C‑3), not a species selection from a disclosed class. If the examiner treated the phenyl→thienyl change as a structural departure rather than a mere species pick, allowance is explicable. (Caveat: I could not verify in this session whether any pre-1986 reference expressly disclosed a 3-heteroaryl-3-aryloxypropanamine; I hit the tool-step limit. That absence is the crux of the patentee's case and should be independently confirmed.)
2. Unexpected results — the dual-uptake property. The '269 specification frames the invention as "novel 3-aryloxy-3-substituted propanamines which are potent inhibitors of both serotonin and norepinephrine uptake," in explicit contrast to fluoxetine (SSRI) and tomoxetine (NRI). The comparative data (specification Table I; synaptosomal ³H‑5‑HT/¹⁴C‑NE assays) showing that the thienyl/naphthalenyloxy compounds are balanced dual inhibitors rather than selective for one transporter is a colorable In re Soni-style showing — and the closest prior art ('404) had deliberately sorted compounds into high and low 5‑HT/NE ratio extremes, which can be argued as a teaching away from seeking a balanced ratio.
3. Actual litigation outcome. In Eli Lilly & Co. v. Wockhardt (S.D. Ind.), the court's March 21, 2011 Final Judgment found infringement of claims 10 and 11 of the '269 patent by Wockhardt's generic duloxetine HCl and "confirm[ed] the validity and enforceability of the '269 patent," notwithstanding Wockhardt's obviousness defense directed to "prior art compounds disclosed by Molloy, et al." The April 27, 2011 order then resolved the remaining defendants by stipulated dismissal and Paragraph III conversions. Sources: Finnegan press release; Wockhardt discovery order, 1:08‑cv‑01547, D.I. 252; order/stipulation, 1:08‑cv‑1547. Caveat: the announcement states a validity finding as to Wockhardt; whether all nine defendants abandoned invalidity on the merits, or merely converted to Paragraph III for commercial reasons, is not established by the documents I retrieved. Do not overstate this as a nationwide merits adjudication of the § 103 question.
4. Secondary considerations. Commercial success (Cymbalta as a blockbuster, including the SUI and diabetic-neuropathic-pain indications), long-felt need for an antidepressant combining serotonergic and noradrenergic activity, and the existence of the Orange Book listing through pediatric exclusivity (Dec. 11, 2013) are the classic objective indicia; note that success must be linked to the claimed compound rather than to formulation/enteric-coating effects — a point defendant Wockhardt actually litigated by seeking discovery on Lilly's enteric-coated formulation and IND 37,071 (see the discovery order above).

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7. Confidence and open items

If I were framing the office action: reject claim 1 under § 103 over '895 (or '896) in view of the art-recognized benzene/thiophene bioisosterism and the '404 disclosure that the 5‑HT/NE ratio is tuned by aryl substitution; reject the N‑methyl species further in view of '081; reject the formulation claims further in view of '009; reject the method claims further in view of '895's own antidepressant method claim and the '081/'404 mechanism disclosure; and reject the salt/enantiomer claims as conventional variants. The patentee's answer, and the reason the claims survived both prosecution and the Cymbalta litigation, is the unexpected balanced dual-uptake profile — so any serious challenge must meet that evidence head-on with close prior-art compounds and comparative data rather than with bioisosterism rhetoric alone.