US 7393939

I'll search for authoritative information on US patent 7393939, including any 2026 CAFC docket activity.

Let me run a couple more targeted searches to check for any litigation or CAFC activity specific to this patent.

US Patent 7,393,939 — Summary

Caveats up front: The patent-number search hit no CAFC 2026 docket activity or litigation involving 7,393,939. Two searches returned only unrelated cases (e.g., a "7393939" string in a Kyocera/Imperium stipulation, and the Gamevice v. Nintendo " '393 patent" — a different patent, U.S. Patent 8,939,393). I found no authoritative record of any 2026 Federal Circuit appeal, IPR, or district-court case naming this patent. Treat that as "no activity found," not proof of none.

Bibliographic data (from the patent text and Google Patents/Justia records)

Procedural note: This is a divisional of U.S. Ser. No. 09/786,261 (issued as U.S. 6,673,898 B1), which was a continuation of PCT/JP2000/003878 (WO 2001/002562 A1). The same family includes JP 4435334 B2, EP 1108784 B1, CA 2340795 C, and DE 60038531 T2.

Abstract (verbatim)

"A novel organic anion transporter gene participating in organic anion transport in the placenta; and an organic anion transporter which is a polypeptide encoded by the gene. A placental organic anion transporter OAT4, more particularly, a placental organic anion transporter OAT4 having the amino acid sequence represented by SEQ ID NO:2 or an amino acid sequence derived therefrom by deletion, substitution or addition of a part of the amino acids thereof. A nucleic acid (preferably DNA) having a base sequence encoding the placental organic anion transporter OAT4 or a base sequence hybridizable therewith under stringent conditions."

Independent claim — plain-language overview

Claim 1 (the sole claim; independent):

"An isolated nucleic acid encoding a protein comprising the amino acid sequence of SEQ ID NO:2."

Plain language: The claim covers any isolated nucleic acid (e.g., DNA/cDNA or RNA) that encodes a protein containing the amino acid sequence of SEQ ID NO:2 — the human OAT4 polypeptide. Because it uses "comprising," it reads on nucleic acids encoding that sequence even with additional amino acids attached; it is a composition-of-matter claim to the encoding nucleic acid, not to the protein itself, and not to methods of use.

Notable narrowing relative to the specification: The written description describes broader subject matter — the OAT4 protein itself, variants with deletions/substitutions/additions (up to ~110 residues, ≥75–90% homology), hybridizing nucleic acids, probes of ≥14 contiguous bases, expression vectors/hosts, and antibodies. The granted claim captures only the encoding nucleic acid, and only via the specific SEQ ID NO:2 amino acid sequence rather than the SEQ ID NO:1 base sequence or the hybridization language.

Family cross-check on claim count

The parent U.S. 6,673,898 B1 issued with 2 claims (claim 1 being "[t]he isolated organic anion transporter OAT4 of a placenta type…", i.e., a protein claim), whereas this divisional 7,393,939 issued with the single nucleic-acid claim above. This division of claim types between parent and divisional is consistent with a restriction requirement.

Uncertainty flags

• Assignee: Sources conflict. Google Patents lists the original assignee as Japan Science and Technology Corp. and the current assignee as J. Pharma Co., Ltd. (per the recorded 2008 assignments to Endou, Sekine, and J. Pharma). Justia's "Patent History" still shows Japan Science and Technology Corporation. The Google Patents assignment record is the more current authority.
• A third-party aggregator (patentleaderboard.com) attributes the patent to "Hamamatsu Photonics K.K."; this appears to be an aggregation artifact and is not corroborated by USPTO assignment records — treat it as unreliable.
• I have no authoritative information that this patent was ever litigated or appealed, including in any 2026 CAFC docket. Absence of hits may reflect search limitations rather than confirmed absence of activity.

Sources

• https://patents.google.com/patent/US7393939/en (authoritative full text supplied)
• https://patents.justia.com/patent/7393939 (bibliographic/patent-history corroboration)
• https://patents.google.com/patent/[US6673898](/patent/US6673898) (parent patent, 2 claims)
• https://patents.google.com/patent/JP4435334B2/en (family member)

I'll search for litigation involving US patent 7393939 across patent litigation sources.

Let me search more targeted litigation databases.

Let me try more specific searches for litigation and PTAB proceedings on this patent.

Summary of Findings — U.S. Patent No. 7,393,939

Bottom line: I found no evidence of any litigation (district court, ITC, CAFC, or PTAB) involving U.S. Patent No. 7,393,939.

What I searched

• General web searches for "US 7,393,939," "7,393,939," and "7393939" combined with litigation/lawsuit/infringement terms
• CourtListener (PACER/RECAP) and Justia dockets
• Unified Patents litigation/PTAB references and PTAB (PTACTS) filings
• Full-text queries pairing the number with "IPR," "inter partes review," and "PTAB"

Important caveat on "false positives"

Every hit I retrieved for a "’939 patent" was a different patent and should not be attributed to U.S. 7,393,939. Specifically:

• Celgene pomalidomide/ANDA litigation (e.g., Celgene Corp. v. Hetero Labs Ltd., D.N.J. 2:17‑cv‑03387) — the "’939 patent" there is a Celgene formulation patent, not 7,393,939.
• Vivato Networks / XR wireless litigation (E.D. Tex.) — a "’939 patent" from application 10/700,342, unrelated.
• Meso Scale Diagnostics v. Roche — a different "’939 patent" (diagnostics).
• LG Innotek, IPR2019‑01159/01160 — concerns U.S. 9,530,939.
• Changer & Dresser v. 002152706 Ontario (IPR2017‑00341) — concerns U.S. 9,393,639.

None of these involve U.S. 7,393,939.

What is known about the patent itself (from the patent record)

• Title: "Placental organic anion transporter and gene thereof" (organic anion transporter OAT4)
• Inventors: Hitoshi Endou, Takashi Sekine, Seok Ho Cha
• Original assignee: Japan Science and Technology Corp.; later reassigned (2008) to J. Pharma Co., Ltd. and to the inventors Endou/Sekine
• Family: Divisional of U.S. Ser. No. 09/786,261 (now U.S. 6,673,898); CIP of PCT/JP2000/003878; claims priority to JP 11‑187244 (July 1, 1999)
• Claim 1 (only claim): "An isolated nucleic acid encoding a protein comprising the amino acid sequence of SEQ ID NO:2."
• Status: Expired – Lifetime (adjusted expiration April 11, 2022). A patent this recent in expiration with a single narrow nucleic-acid claim and no commercial product disputes is a plausible explanation for the absence of litigation.
• The record shows 4 cited prior-art documents and no "Related litigation" listings on the patent page.

Confidence and limits

I have moderate-to-high confidence that no litigation exists, based on the absence of any matching records across the sources listed. However, my search was not exhaustive (e.g., I could not complete direct queries against a live Docket Navigator or the Unified Patents portal case list page, and PACER coverage of older/quieter dockets can be incomplete). I am flagging this explicitly rather than asserting a definitive negative.

If you need a definitive confirmation, the most authoritative next steps would be:

1. Docket Navigator (subscription) — search by patent number for all district, ITC, and PTAB proceedings
2. Unified Patents Portal (https://portal.unifiedpatents.com/litigation) — free case list searchable by patent
3. USPTO PTAB — search for IPR/PGR/CBM petitions naming 7,393,939
4. PACER — party search for "Japan Science and Technology" and "J. Pharma" as assignees/patent owners

If no litigation is known: that is my conclusion — no litigation involving U.S. Patent No. 7,393,939 was identified.

I ran the structured ODP feed against the patent and then tried to corroborate with web searches (Google Patents family page, Justia, PTAB-related queries, and litigation/appeal queries). Here is the honest picture.

Proceedings overview

Total AIA trial proceedings on file for US 7,393,939: 0 — zero IPRs, zero PGRs, zero CBMs; the breakdown across active / invalidated / sustained / settled / institution-denied is therefore 0/0/0/0/0, and the defensive posture this gives a defendant is "no PTAB attack on this patent has ever been filed, but the patent is also expired, so there is no live patent right left to attack or to fear."

This matches the structured "PTAB proceedings on file" block (USPTO Open Data Portal returns no AIA trial proceedings as of the most recent ingest). My independent web searches surfaced no IPR/PGR/CBM petition number, institution decision, Final Written Decision, or Federal Circuit appeal tied to 7,393,939 or its parent 6,673,898. Searches that returned a "7,393,939" hit turned out to be false positives (e.g., a phone number in an unrelated N.D. Cal. stipulation), not proceedings against this patent.

No AIA trial proceeding to report

There is no {PROCEEDING_NUMBER} to populate here — I will not manufacture one. The canonical ODP list is empty and no public source contradicts it. For completeness, the fields the template asks for would be:

• Type: N/A
• Filed: N/A
• Status: N/A
• Judge panel: N/A
• Petition grounds: N/A
• Institution decision: N/A
• Final Written Decision: N/A
• Settlement / termination: N/A
• Appeal: N/A
• Defensive value: No IPR estoppel, no FWD canceling or sustaining any claim, and no PTAB record to leverage — but also no live enforcement exposure, because the patent is expired (see below).

Caveat on completeness: ODP ingest can lag, and a very old, never-asserted patent is exactly the profile where nothing turns up. I could not fully rule out an obscure district-court or ITC use of the patent — my searches did not reveal one, but I cannot affirm a negative to a certainty. If you need certainty, the authoritative check is the USPTO PTAB E2E / Patent Trial and Appeal Board docket search for the patent number and the CourtListener docket search: PTAB E2E and CourtListener.

Strategic summary

Claim status. US 7,393,939 has exactly one claim (claim 1): "An isolated nucleic acid encoding a protein comprising the amino acid sequence of SEQ ID NO:2." No PTAB proceeding ever reached that claim, so it is neither canceled nor sustained by any FWD — it is simply untested at the PTAB. The significant fact for a defendant is not claim-level survival, it is patent-level expiration: Google Patents records the legal status as Expired - Lifetime, adjusted expiration 2022-04-11, with the underlying priority date of 1999-07-01. Whatever claim 1 covers, the patent term ran out in April 2022. Note this is a divisional of US 6,673,898 (which issued from U.S. Ser. No. 09/786,261, the national-stage entry of PCT/JP2000/003878); that parent and the family (EP1108784B1, JP4435334B2, CA2340795C) share the same 1999 priority and are likewise expired or near-expired. A defendant facing a demand letter citing this family should check the expiration date first — a demand premised on an expired patent supports no injunction and, absent a still-open damages window for past infringement, no ongoing royalty.

Estoppel landscape. Because no IPR was ever instituted, there is no § 315(e)(2) estoppel running against anyone, and no petitioner/privity chain to trace. Conversely, there is also no petitioner-side benefit to inherit. Practically, the estoppel question is academic: with the patent expired, the dominant defenses for a defendant today are (a) no enforceable term remains (expiration 2022-04-11), (b) § 286 damages look-back (six years) and the § 287 marking defense for any pre-expiration recovery theory, and (c) on the merits, the actual claim scope — a single nucleic-acid claim to "a protein comprising the amino acid sequence of SEQ ID NO:2," which is narrow and invites non-infringement arguments based on sequence identity as much as invalidity arguments.

Pattern signals. No petitioner has ever filed on this patent — no repeat filer, no serial-attack pattern, and no defensive aggregator (Unified Patents, RPX, etc.) appears anywhere in the chain. The patent owner history is institutional/academic rather than a troll pattern: original assignee Japan Science and Technology Corp., inventor-assigned to Hitoshi Endou and Takashi Sekine (2008-05-16), then to J. Pharma Co., Ltd. (effective 2008-05-24). The patent reached its full 20-year-plus term, paid maintenance fees through the 12th-year payment (2019-12-23), and expired. There is no PTAB appeal to report and no Federal Circuit activity I could find.

Recommended next steps

• If you are a defendant being asserted against today: the threshold question is whether the asserted claim is even in force. Confirm the expiration against the USPTO PatentCenter (adjustment to 2022-04-11 per Google Patents) and check whether the demand is really about liability on a lapsed patent versus past damages within the § 286 six-year window. If the demand cites only claim 1 and the patent is expired, the exposure is at most historical — not injunctive.
• There is no FWD to link or quote. I will not fabricate one. The absence of any PTAB proceeding is the substantive finding: this patent was never subjected to an AIA validity challenge in the ~14 years it was enforceable and assertable. That is itself a signal — well-asserted patents tend to attract IPRs — and suggests the patent was never a meaningful litigation target (consistent with the absence of any district-court or ITC hit in my searches).
• No trial-stage milestones to track. There are no pending proceedings, so there is no institution-decision deadline, no oral hearing date, and no statutory 1-year FWD due date to calendar. Nothing is active.
• If you want to be certain the ODP feed is not merely stale: run the patent number directly through PTAB E2E and search CourtListener for both 7,393,939 and 6,673,898. I searched and found nothing, but a direct docket pull is the conclusive check for a patent this old.

Bottom line: there is no PTAB fight to brief on US 7,393,939. The patent has a single claim, no AIA trial history, and an expiration date of 2022-04-11 — a defendant's fastest path to closing out a demand letter is the calendar, not the Board.

I'll cross-check the assignment records against external sources before reconstructing the chain.

Let me check for the actual USPTO assignment records and any litigation history for this patent.

Assignment & Ownership Analysis — US 7,393,939 B2

Sourcing note (read first): I was able to retrieve the two post-issuance assignment records below from the Google Patents mirror of the USPTO assignment data (reel/frame, assignor/assignee, execution and recording dates are given). I was not able to pull the live Assignment Center entries for correspondents of record — the USPTO Assignment Search / Assignment Center pages did not return content to my queries, and my step budget ended before I could retry alternate endpoints. Every correspondent field below is therefore "not available in the retrieved records," not "no correspondent." Treat that gap as a limitation, not a finding.

Inventors

Pattern note: The unusual feature here is not inventor flight. The original assignee is Japan Science and Technology Corporation / Agency (JST) — the Japanese government-affiliated technology-transfer organization — and the 2008 assignments move the patent out of JST and back to the inventors, who then convey it to J-Pharma Co., Ltd., the company Endou himself founded (J-Pharma's own corporate history shows founder/CEO Hitoshi Endou). That is an inventor spin-out, not a portfolio fire-sale. One caution: the third-party aggregator patentleaderboard.com attributes this patent to Hamamatsu Photonics K.K. via a "Takashi Sekine" match; that is an aggregation artifact (name collision across unrelated inventors) and is not corroborated by any USPTO record — disregard it.

Original assignee

Japan Science and Technology Corporation (Saitama-ken), later renamed Japan Science and Technology Agency (JST) — the patent names "Japan Science and Technology Corp." as original assignee, and the recording identifies "JAPAN SCIENCE AND TECHNOLOGY AGENCY (FORMERLY KNOWN AS JAPAN SCIENCE AND TECHNOLOGY CORPORATION)."

• Primary line of business: Government-backed science/technology funding and technology-transfer organization; it does not manufacture products.
• Shipped a product embodying the claims? No. JST is a funding/TTO entity, not an operating manufacturer.
• Current status: Operating (as the Agency). Its interest in this patent, however, was fully divested in 2008 (see chain below).

Current owner of record: J. Pharma Co., Ltd. (Japan) — an operating drug-discovery company founded 2005-12-26; ~16–18 employees; focused on SLC-transporter-targeted drugs (LAT1 inhibitor Nanvuranlat/JPH203); listed on the Tokyo Stock Exchange Growth Market 2026-03-25 (ticker 520A). It develops and licenses its own pipeline and research-tool patents — a genuine operating company, not a holding vehicle.

Assignment timeline

Two recorded assignments, both executed May 2008 and both recorded 2008-06-16, just before the 2008-07-01 issue date.

• 2008-05-16 (executed) / recorded 2008-06-16 — Reel 021096/0451

  • Conveyance: Assignment
  • Assignor: Japan Science and Technology Agency (formerly Japan Science and Technology Corporation)
  • Assignee: Hitoshi Endou (Japan) and Takashi Sekine (Japan) — both listed as owners on this reel/frame
  • Correspondent: not available in the retrieved records (the patent's prosecution attorney of record is Edwards Angell Palmer & Dodge LLP per Justia, but that is not the assignment-recording correspondent and should not be conflated with it)
  • Context: Internal/ownership reassignment — the government tech-transfer agency returns rights to the inventors.

• 2008-05-24 (executed) / recorded 2008-06-16 — Reel 021096/0457

  • Conveyance: Assignment
  • Assignor: Hitoshi Endou; Takashi Sekine (the assignors named in the record: "ENDOU, HITOSHI; SEKINE, TAKASHI")
  • Assignee: J. Pharma Co., Ltd. (Japan)
  • Correspondent: not available in the retrieved records
  • Context: Transfer to the inventors' own operating company (inventor spin-out); J-Pharma has held it since.

No further recorded assignments. Notably, there is no assignment record for the 2016 Ardea Biosciences/AstraZeneca transaction covering OAT4 — J-Pharma's own announcement (2016-05-10) describes it as a non-exclusive license, i.e., not a conveyance, so no assignment reel/frame would be expected. Similarly, J-Pharma's 2015 research-tool licensing program is license-only. If the Assignment Center shows additional records beyond these two, they were not visible to me.

Timeline diagram

timeline
    title Ownership of US 7393939
    1999 : Priority filing in Japan
    2005 : J Pharma founded by Endou
    2008 : JST assigns rights to inventors
         : Inventors assign to J Pharma
         : Patent issues Jul 1
    2016 : Non exclusive license to Ardea

NPE / troll-pattern signals

1. Shell-entity transfer — not present. The 2008 transfers run toward a real operating company, J-Pharma (founded 2005, TSE-listed 2026, pipeline of its own drugs), and originate from a government TTO. There is no "IP/Licensing/Holdings" LLC, no registered-agent address, and no single-purpose Delaware/Texas vehicle. Reel 021096/0457.

2. Known asserter in the chain — not present. Neither JST/JSPS nor J-Pharma appears on the RPX/Unified/Patent Progress high-frequency-plaintiff lists. J-Pharma's public posture is outbound non-exclusive licensing of research-tool patents (2015 program; 2016 Ardea/AstraZeneca deal covering OAT1/OAT4/URAT1), which is the opposite of an assertion campaign.

3. Repeat correspondent across the chain — unclear. No correspondent data retrieved (see sourcing note). Even if a firm recurs, a single firm doing both operating-company and NPE filings is not a finding; the signal requires recurrence, which I cannot establish here.

4. Cascading transfers — not present. Exactly two recorded assignments, both in a single week of May 2008, both recorded the same day (2008-06-16). No chained LLCs, no <24-month cascade.

5. Pre-litigation transfer — not present. No infringement suit naming this patent was located in any district court or at the Federal Circuit (consistent with the prior section's finding of no 2026 CAFC/litigation activity). With no suit, the "within 6 months before first suit" trigger cannot be satisfied.

6. Bankruptcy fire-sale — not present. No bankruptcy of JST or J-Pharma found; the transfer was a deliberate technology spin-out, and the patent remained in J-Pharma's hands through its 2026 IPO.

7. Privateering — not present. No evidence J-Pharma transferred to an NPE to assert on its behalf; it retained ownership and licensed directly.

8. Defensive aggregator — not present. The chain does not terminate at RPX, AST, LOT, Unified, or OIN.

Verdict

Operating-company assertion (with a licensing caveat). The chain terminates at J. Pharma Co., Ltd., a real operating drug-discovery company (founded by inventor Hitoshi Endou, TSE Growth-listed 2026) that retains ownership of the patent per reel 021096/0457 and monetizes it through non-exclusive licenses (e.g., the 2016 Ardea Biosciences/AstraZeneca deal covering OAT1/OAT4/URAT1) rather than litigation — no NPE-style shell, cascade, or asserter-chain signal is present. Strictly construed, this is closer to an operating-company licensor than a litigating asserter, but among the available verdict categories it is the only one supported: the sole recorded transfers (reel 021096/0451 and 021096/0457, both recorded 2008-06-16) run JST → inventors → operating company, with nothing pointing to an NPE.

Verification link: https://assignment.uspto.gov/patent/index.html (search "7393939") / https://assignmentcenter.uspto.gov/

Caveats: (i) Correspondents of record were not retrievable, so signal 3 is unresolved rather than negative; (ii) I did not find any suit or 2026 CAFC docket activity, which is evidence only of absence of found activity; (iii) the initial inventor→JST assignment (if any) predates the retrieved post-grant legal events and is not shown here.

I'll research each cited reference and verify details against authoritative sources.

Prior-Art Analysis — US 7,393,939 B2 ("Placental organic anion transporter and gene thereof")

Scope note and caveats (read first)

Per the strict rule, I interpret all identifiers literally. Two things must be flagged before walking the citations:

1. I could not retrieve a live USPTO "Patent Center" prior-art listing for this number through the searches run here. The citation set below is taken from the authoritative full text supplied for US 7,393,939 (Google Patents, https://patents.google.com/patent/US7393939/en), which lists 4 patent citations and 31 non-patent citations. Each of the four patent citations carries the asterisk legend meaning "cited by examiner." Treat the examiner-citation attribution as from Google Patents' rendering, not a certified USPTO Form PTO-892.
2. This is a single-claim patent. Claim 1 (the only claim) reads: "An isolated nucleic acid encoding a protein comprising the amino acid sequence of SEQ ID NO:2." Because there is only one claim, every § 102 question collapses to the same question: does the reference disclose a nucleic acid encoding the OAT4 polypeptide of SEQ ID NO:2? That framing matters for the analysis below.

Applicable law: The patent has a 1999 priority date and was filed/granted well before March 16, 2013, so pre-AIA 35 U.S.C. § 102 governs. The effective U.S. filing date is the international filing date of PCT/JP2000/003878, June 15, 2000 (35 U.S.C. § 363), with the § 119 benefit of JP 11-187244/1999, July 1, 1999. The § 102(b) critical date is therefore June 15, 1999, and the presumptive invention date is July 1, 1999.

Part 1 — Patent citations (all four examiner-cited)

1. WO 1998053064 A1 — "Organic anion transporter and gene coding for the same"

Description. This is the closest patent reference. Per the Google Patents text, it discloses the rat organic anion transporter OAT1 (full-length cDNA, ~2.2 kbp) and the human OAT1 (SEQ ID NO:2 therein; 563 amino acids), derived from kidney, together with functional data in Xenopus oocytes (PAH uptake, rNaDC-1 co-expression, sodium-dependence, substrate/inhibitor panels). It expressly describes the OAT family and recites a now-familiar genus: proteins having "one or several amino acids deleted, substituted or added," "usually 1 to about 110, preferably 1 to about 55," with homology "80% or more, preferably 90% or more," plus DNA hybridizing under stringent conditions (5×SSC at 37–42 °C, washing at 1×SSC, higher stringency at 0.1×SSC). This is essentially the same boilerplate genus language that appears in the '939 specification — a point relevant to any § 112 or § 103 argument, but not to anticipation.

§ 102 analysis. This reference is § 102(a) and § 102(b) prior art (published 1998-11-26, both before the July 1, 1999 invention date and more than one year before the June 15, 2000 filing date). However, it does not anticipate claim 1. Anticipation requires that a single reference disclose every limitation — here, an isolated nucleic acid encoding the protein comprising the amino acid sequence of SEQ ID NO:2 (human OAT4). WO 98/53064 discloses OAT1 sequences, not the OAT4 sequence. The '939 specification itself acknowledges the distinction, noting OAT1/OAT2/OAT3 are "around 40%" homologous to one another and that the inventors retrieved an EST database to find a new member. Accordingly, this reference is properly characterized as (i) background art showing the state of the OAT family, and (ii) § 103 obviousness art — not § 102 anticipation art.

2. WO 1999013072 A1 — "Transporter genes"

Description. Discloses novel transporter genes isolated from a human fetal library by random sequencing of a subtraction library, homologous to the organic cation transporters OCT1/OCT2 → designated hOCTN1 (SEQ ID NOS: 1/2) and hOCTN2 (SEQ ID NOS: 3/4), plus mouse OCTN1/OCTN2 (SEQ ID NOS: 22/23, 27/28). Functional data show transport of organic cations (TEA, carnitine, quinidine, pyrilamine), and the claims are drawn to proteins/DNAs/hybridizing ≥15-mers with organic-cation transport activity. Related family member US 7,947,470 B2 ("Polynucleotides encoding hOCTN1 polypeptide") descends from the same disclosure.

§ 102 analysis. § 102(a)/§ 102(b) prior art (published 1999-03-18, before the invention date and more than one year before June 15, 2000). It does not anticipate claim 1. The disclosed transporters are organic cation transporters of the OCTN subfamily (SLC22A4/SLC22A5 lineage), not the organic anion transporter OAT4, and none of its SEQ ID NOs is the OAT4 protein/nucleic acid. This reference is § 103 art at most (evidence that the SLC22 transporter superfamily was being mined by homology cloning), and it also supplies the broad "substitution/deletion/addition + hybridizing DNA + ≥15-mer probe" genus language that the '939 claims deliberately narrowed away from.

3. WO 2001049728 A2 — "HUMAN PROTEINS HAVING HYDROPHOBIC DOMAINS AND DNAs ENCODING THESE PROTEINS"

Description. A "hydrophobic-domain" genomics disclosure: cloned human cDNAs encoding proteins predicted to be secretory/membrane proteins on the basis of hydrophobicity plots. Claims recite proteins comprising any of SEQ ID NOS: 1–10, 31–40, 61–70, 91–100, 121–130; isolated DNAs encoding them; cDNAs of SEQ ID NOS: 11–20, etc.; expression vectors; transformed eukaryotic cells; antibodies. The European counterpart is EP 1 254 221 A2 (withdrawn).

§ 102 analysis — timing problem, flagged explicitly. Every date for this reference (priority 2000-01-06; international filing 2000-12-28; publication 2001-07-12) postdates the '939 priority date of 1999-07-01. Under pre-AIA § 102 it therefore cannot be prior art against claim 1:

• § 102(a)/(b) require the disclosure to predate the invention/statutory-bar date — it does not.
• § 102(e) requires the reference application to have been filed before the applicant's invention — the earliest date here (2000-01-06) is ~6 months after the July 1, 1999 invention date; its international filing date (2000-12-28) is even later.

Conclusion: not anticipatory, and not even citable as § 102 art on the face of the dates. It is at most contextual evidence of the crowded "hydrophobic-domain ORF" art, and would only become relevant if the applicant's priority claim to JP 11-187244/1999 were successfully challenged. The examiner's citation of it is best explained as a completeness/§ 103-trajectory citation, not a § 102 ground.

4. WO 2001062923 A2 — "Transporters and ion channels"

Description. Discloses "TRICH-1" through "TRICH-13" — isolated polypeptides (SEQ ID NOS: 1–13), polynucleotides encoding them (SEQ ID NOS: 14–26), probes, expression vectors, host cells, antibodies, arrays and screening methods; corresponding US application published as US 2006/0035315 A1. Of note for this family: Incyte's SEQ ID NO:13 (clone 6879618CD1; representative library PLACNOR01 — a placenta library) is annotated as a "putative integral membrane transport protein [Rattus norvegicus]" whose nearest homolog is GenBank g3004482 (Schömig et al. (1998) FEBS Lett. 425:79–86). That is an SLC22-family transporter isolated from human placenta — i.e., conceptually adjacent to the OAT4 subject matter — which is plausibly why the examiner pulled it.

§ 102 analysis — timing problem, same as item 3. Dates are priority 2000-02-25; PCT filing 2001-02-23; publication 2001-08-30, all after the 1999-07-01 invention date. So not § 102(a), (b) or (e) art against claim 1 on these dates. It does not anticipate claim 1 — and, independently of timing, it does not disclose a nucleic acid "encoding a protein comprising the amino acid sequence of SEQ ID NO:2" of the '939 patent (it discloses its own SEQ ID NOS 1–26). Note the internal documentary wrinkle worth recording: the Schömig 1998 FEBS Lett. g3004482 homolog it relies on is pre-1999 art, but that underlying publication is not itself a "patent citation" of the '939 patent.

Part 2 — The genuinely anticipatory-type references are in the non-patent set

Because all four patent citations fail to anticipate claim 1, the most legally pointed art sits in the 31 non-patent citations, two of which are database entries that existed before the invention:

Part 3 — Bottom line

Claim-by-claim § 102 result for the sole claim:

Net conclusion: No reference cited against US 7,393,939 anticipates claim 1 under 35 U.S.C. § 102. The two WO references that are timely (Tanabe Seiyaku's OAT1 and Chugai's OCTN genes) are directed to different transporters and are properly § 103 (and § 112-genus) references. The two later-published WO references (Protegene, Incyte) postdate the 1999-07-01 priority date on every date shown and are therefore not § 102 prior art to this claim; their citation is best understood as generic-genomics context. The closest anticipation-adjacent art is actually the pre-1999 EMBL EST H12876/N54154, but those fragments cannot read on a claim requiring a nucleic acid encoding the complete SEQ ID NO:2 polypeptide.

Cross-check against the prior section (no contradiction): the earlier bibliographic summary reported a single claim and an expired 2022-04-11 adjusted expiration with no litigation/CAFC activity found. That is consistent with everything above — a narrow, single-sequence claim that issued without an apparent § 102 rejection requiring these references to be resolved adversarially.

Sources

• https://patents.google.com/patent/US7393939/en (authoritative citation lists; claim 1; specification)
• https://patents.google.com/patent/WO1998053064A1/en (Tanabe Seiyaku OAT1 disclosure and genus language)
• https://patents.google.com/patent/WO1999013072A1/en and https://patents.google.com/patent/US7947470 (Chugai hOCTN1/hOCTN2; family)
• https://patents.google.com/patent/EP1254221A2/en and https://pubchem.ncbi.nlm.nih.gov/patent/WO-0149728-A2 (Protegene; dates)
• https://patents.google.com/patent/US20040034192A1/en and https://uspto.report/patent/app/20060035315 (Incyte TRICH; SEQ ID NO:13 and PLACNOR01 library; priority dates)
• https://patentimages.storage.googleapis.com/bf/46/56/2b686a2028ee0b/[US6673898](/patent/US6673898).pdf (parent patent text; H12876 probe; Examples)

I'll analyze the obviousness question under § 103 using the prior-art references identified on the patent page. Let me first gather details on the key references.

Let me gather more specifics on the EST fragment and OAT family sequences, which are central to the obviousness analysis.

Obviousness Analysis — U.S. Patent No. 7,393,939 B2 (35 U.S.C. § 103)

Caveat / scope: This is a technical patent-analysis opinion, not legal advice. Obviousness is a question of law based on underlying facts (Graham v. John Deere Co., 383 U.S. 1 (1966)), and a definitive conclusion would require the full text of each reference, the prosecution history, and any Rule 132 evidence. I flag below where I am working from the portions of the references available to me. I also note at the outset that the patent expired April 11, 2022 and (per the earlier sections of this report) no litigation or PTAB/CAFC challenge was identified, so this analysis is academic rather than operative.

1. The claim and its effective filing date

Claim 1 (the sole claim):

"An isolated nucleic acid encoding a protein comprising the amino acid sequence of SEQ ID NO:2."

• SEQ ID NO:2 is the human OAT4 polypeptide (UniProt Q9NSA0, SLC22A11), 550 amino acids; SEQ ID NO:1 is the 2,210-bp cDNA. (Confirmed against UniProt and the inventors' own later paper, Cha et al., J. Biol. Chem. 275:4507–4512 (2000).)
• Because the claim uses "comprising," it reads on any isolated DNA or RNA encoding SEQ ID NO:2 with or without additional residues — including expression constructs, tags, and codon-degenerate variants.
• Effective date / governing law: Priority is JP 11‑187244 (July 1, 1999); the application is a divisional of 09/786,261, a § 371 national stage of PCT/JP2000/003878 (int'l filing June 15, 2000). The patent is therefore governed by pre‑AIA § 102/103. For the § 102(b) bar, the critical date is one year before the U.S./international filing date, i.e. ~June 15, 1999 (a foreign priority date cannot antedate a § 102(b) reference).

Consequence: every reference relied on below was published before June 15, 1999, so each is § 102(b) prior art and usable for § 103 without any priority/antedating dispute.

2. Level of ordinary skill in the art

A Ph.D. (or M.S. with several years' experience) in molecular biology/biochemistry with working familiarity with: (a) expression cloning and oocyte uptake assays; (b) cDNA library screening with labeled probes; (c) public sequence databases (GenBank/EMBL) and homology searching; and (d) membrane-transporter biology. This is the level reflected in the references themselves (e.g., Sekine 1997; Kusuhara 1999).

3. Scope and content of the prior art of record

References that are NOT prior art (important): the record's citation list also includes Cha et al. 2000, Pavlova 2000, Enomoto 2002, Babu 2002, Ekaratanawong 2004, Hong 2004, Miyazaki 2005, Sakura 2004, Strausberg 2002, Sykes 2004, and WO 2001/049728 and WO 2001/062923. All post-date July 1, 1999; several post-date even the June 15, 1999 § 102(b) critical date. None may be used for § 103.

4. The two decisive facts

1. The OAT family was known and known to be a family. OAT1/OAT2/OAT3 shared only ~40% amino acid identity, yet were all multispecific organic-anion transporters (patent, col. 1; Sekine 1997; Sekine 1998; Kusuhara 1999). OAT4 is 44% identical to human OAT1, 43% to rat OAT1, 38% to rat OAT2, and 43% to rat OAT3 (Cha et al. 2000).

2. The critical lead was public before the priority date. H12876 (1995) is a public EST encoding the C-terminal ~114 residues of OAT4 plus 3′UTR. The inventors' own specification concedes the workflow: "an EST database … was retrieved, and a novel cDNA fragment H12876 having a homology to OAT1, OAT2 and OAT3 was obtained. Using a probe where this H12876 was labeled with ³²P, the present inventors screened a human kidney cDNA library" (US 7,393,939, Description; mirrored in US 6,673,898).

In other words, the claimed molecule differs from the prior art principally by (i) completing the N‑terminal ~436 codons of an ORF for which a public, gene-specific probe already existed, and (ii) the incidental fact that the resulting gene turned out to be a new family member.

5. Prima facie case: combinations that would render Claim 1 obvious

Combination A (strongest) — OAT1 + OAT2 + OAT3 + H12876 (± Hillier 1996)

Motivation to combine: The references expressly state that OAT1/2/3 "show that organic anion transporters form a family" (patent, col. 1, ¶ citing Sekine/Kusuhara). Once a gene family is identified, mining it for additional members is a routine, recognized objective (cf. Chugai's WO 1999/013072, which does exactly this for the OCT family). The EST database was a standard tool (Hillier 1996), and H12876 is a specific, unique lead — not a random screen — that hybridizes to a single cognate gene.

Reasonable expectation of success: Probe-based screening of a cDNA library with a gene-specific EST reliably yields the full-length clone of that gene; there was no unpredictability about which gene would be retrieved once H12876 was chosen as the probe.

KSR v. Teleflex (550 U.S. 398 (2007)) fit: "a finite number of identified, predictable solutions" and an "obvious to try" situation; a predictable variation on a known, finite gene family. Under this framework the claim is obvious.

Combination B — WO 1998/053064 (Tanabe) + WO 1999/013072 (Chugai) + H12876

Tanabe supplies the homology/genus template (≥80% identity; DNA hybridizing under stringent conditions) and the human OAT1 sequence; Chugai supplies the methodology of homology screening to isolate new transporter genes. A POSITA would combine these to hunt for further OATs. (Caveat: OAT4 at 44% identity falls outside Tanabe's ≥80% genus, so Tanabe does not itself encompass the claim — it supplies motivation and method, not the species.)

Combination C — A or B + Van Der 1994 / Endou 1998

Van Der (placental barrier) and Endou (renal transporter physiology) supply the rationale that an anion transporter should exist in placenta, and the patent itself derives its "placenta" characterization from this reasoning (col. 1). This bolsters the motivation to look in kidney/placenta libraries.

Claim chart (Combination A)

There is no anticipation (§ 102) — no reference discloses the full-length encoding sequence. The case rises or falls on § 103.

6. Counterarguments that could defeat the prima facie case

(a) The In re Deuel / In re Bell line. In re Deuel, 51 F.3d 1552 (Fed. Cir. 1994), and In re Bell, 991 F.2d 781 (Fed. Cir. 1993), hold that a claim to a DNA molecule is not obvious merely because a protein is known and general cloning methods exist, because the genetic code is degenerate and the specific nucleotide sequence cannot be predicted. Under that framework, the fact that a skilled artisan could isolate the gene does not make the specific claimed nucleic acid obvious. In re Kubin, 561 F.3d 1351 (Fed. Cir. 2009), later confined Deuel/Bell where the protein is fully known, but Kubin post-dates both the priority date and the issue date and does not directly fit here (the OAT4 protein was not fully known).

(b) H12876 is only a fragment, and its identify was unknown. In 1999 one could not know whether H12876 corresponded to a genuinely new OAT (OAT4) or merely to OAT1/2/3 or another homologous transcript. The specific SEQ ID NO:2 sequence — and hence its encoding nucleic acid — was not predictable.

(c) EST enablement/utility. A government/EST reference that discloses only a partial sequence may not be "enabling" for the full-length coding sequence or for a functional transporter, weakening its use as the anchor of the combination.

(d) Secondary considerations (objective indicia). The specification reports arguably unexpected properties — multispecific substrate range, Na⁺-independent transport, ochratoxin-A transport, and kidney+placenta tissue specificity (FIGS. 1–6). Any § 103 rebuttal via unexpected results, however, faces an attenuated nexus problem for a nucleic-acid claim defined by a protein sequence: the "unexpected" conduct belongs to the protein, and the claim contains no functional limitation tying the DNA to those properties. With no commercial product or litigation found, there is no independent evidence of non-obviousness.

(e) The examiner evidently accepted the Deuel-type position. Both the parent (US 6,673,898, 2 claims to the OAT4 protein) and this divisional (1 claim to the encoding nucleic acid) were allowed, consistent with the view that the unidentified OAT4 protein/sequence was the non-obvious element. That does not bind a later challenger, but it is a fair predictor of how the PTO would have resolved a 1999-era obviousness contest.

7. Bottom line

• Under the law as it stood at the 1999 priority date (Deuel/Bell), the claim is more likely than not non-obvious. No reference discloses the OAT4 protein or a nucleic acid encoding it; the only relevant nucleotide art is a partial EST (H12876) whose correspondence to a distinct new gene was not known, and the full-length sequence could not be predicted.
• Under a KSR-style "predictable result / obvious to try" analysis, Claim 1 is vulnerable. The combination of OAT1 + OAT2 + OAT3 + H12876 (optimally with Tanabe WO 1998/053064 for the genus template and Chugai WO 1999/013072 for the homology-screening methodology, and Van Der 1994/Endou 1998 for the placenta rationale) supplies a specific, gene-unique probe and a routine method that would reliably retrieve the claimed molecule with a reasonable expectation of success.
• Most likely single combination to assert: Tanabe WO 1998/053064 A1 + Kusuhara 1999 (OAT3) + EMBL H12876 + Hillier 1996, with Sekine 1997/1998 as corroborating family members. The H12876 entry is the linchpin — it is the one reference that turns a "family-mining" argument into a "one specific, predictable lead" argument.
• Practical relevance: Given the April 11, 2022 expiration, a single narrow claim, and the absence of any identified litigation, this obviousness question is essentially academic; no validity challenge was located.

Confidence: Moderate on the legal conclusion (the outcome genuinely depends on whether the Deuel/Bell or KSR/Kubin framework controls, and both are argued in good faith); high on the factual predicates (identity percentages, 550-aa length, and H12876's correspondence to OAT4 residues 437–550), which are corroborated by the patent text, the inventors' JBC paper, and UniProt.

Sources

• https://patents.google.com/patent/US7393939/en (authoritative full text supplied)
• https://patents.google.com/patent/US6673898 (parent; family/claim comparison)
• https://patents.google.com/patent/WO1998053064A1/en (Tanabe Seiyaku; OAT1, genus/hybridization teachings)
• https://patents.google.com/patent/WO1999013072A1/en (Chugai; homology-screening methodology)
• Cha et al., J. Biol. Chem. 275:4507–4512 (2000), doi:10.1074/jbc.275.6.4507 (OAT4 cloning; H12876 = residues 437–550 + 3′UTR; identity values)
• UniProt Q9NSA0 (SLC22A11/OAT4, 550 aa); UniProt Q4U2R8/Q8TCC7/Q9Y694 (OAT1/OAT3/OAT2)