US 6005079

I'll search for the specific patent number and related litigation/litigation dockets.

Let me pull the full claim set and check for any 2026 CAFC litigation involving this patent.

US 6,005,079 A — "Immunoglobulins devoid of light chains"

Grounding note: The bibliographic and descriptive data below come from the authoritative full text supplied (Google Patents, https://patents.google.com/patent/US6005079/en) plus corroborating records from FreePatentsOnline (https://www.freepatentsonline.com/[6005079](/patent/6005079).html), RPX Insight (https://insight.rpxcorp.com/patent/[US6005079A](/patent/US6005079A)), Unified Patents (https://portal.unifiedpatents.com/patents/patent/US-6005079-A), and the related family member US 2007/0238133 A1.

Bibliographic data

I found no record of an active 2026 assignment change; the assignee of record is VUB.

Abstract (verbatim)

"There is provided an isolated immunoglobulin comprising two heavy polypeptide chains sufficient for the formation of a complete antigen binding site or several antigen binding sites, wherein the immunoglobulin is further devoid of light polypeptide chains."

Plain-language overview of the claims

Claim 1 — the principal independent claim. An immunoglobulin made of two heavy polypeptide chains, where each heavy chain contains its own antigen-binding site, the molecule contains a variable (VHH) region and a constant region, the constant region lacks the first constant domain (CH1), and the molecule is devoid of polypeptide light chains. In plain terms: a naturally occurring two-chain (heavy-chain-only) antibody of the camelid type. (Verbatim text from RPX, which renders "first" as the typographical error "fist".)

Claim 7 — apparently a second independent claim. Claims 13 and 14 both read "the fragment according to any one of claims 7, or 8 to 12," which shows claim 7 is a fragment claim that does not depend on claim 1. Consistent with the specification, it is directed to a fragment of the heavy-chain immunoglobulin (e.g., a single heavy chain, a papain-derived FVHHh or F(VHHh)₂, or the Fc/pFc fragments described in the disclosure adequately). I could not retrieve the verbatim wording of claim 7 or of claims 2–10 and am flagging that as an unresolved gap rather than reconstructing it.

Claims 8–14 (fragment family), those I could recover verbatim:

• Claim 11 – A fragment of the variable region of the heavy chain of the claim 1 immunoglobulin, comprising a CDR3 domain and including the residue at position 45, where that residue is a charged amino acid or a cysteine, and the fragment has an antigen-specific binding site.
• Claim 12 – The variable region (VHH) of the claim 1 immunoglobulin.
• Claim 13 – A fragment per claim 7 or claims 8–12, wherein each variable region of each heavy chain contains an antigen-binding site.
• Claim 14 – A fragment per claim 7 or claims 8–12 that is an IgG2 or IgG3.

What the claims collectively cover in plain terms: (i) the two-chain, light-chain-free, CH1-deleted heavy-chain immunoglobulin itself; (ii) its fragments, including the isolated VHH domain and CDR3/position-45 variants; and (iii) the IgG2 and IgG3 subclasses. The position-45 limitation in claim 11 captures the hallmark camelid feature described in the specification — position 45 of framework 2 is almost always leucine in conventional four-chain VH (98%), but is replaced in camelid VHH by arginine, cysteine or glutamic acid, which promotes solubility in the absence of VL.

Family / continuations

This patent sits at the head of a large family. Direct descendants listed on Google Patents and in US 2007/0238133 A1 include:

• US 6,765,087 B1 (from Ser. No. 09/293,769, filed Apr. 19, 1999)
• US 7,722,871 B2; US 7,786,047 B2 (both filed Feb. 10, 2006)
• US 7,790,367 B2 (filed Sep. 14, 2006)
• US 2004/0253638 A1; US 2006/0121026 A1; US 2007/0238133 A1; US 2011/0257372 A1

Related family members also include US 5,759,808 and US 5,840,526 (the latter claiming the position-45 limitation in independent-claim form). The underlying scientific disclosure is Hamers-Casterman et al., Nature 363:446–448 (1993), which is cited as prior art/non-patent literature on the face of the patent.

CAFC 2026 docket check — negative finding

I found no evidence of any 2026 Court of Appeals for the Federal Circuit docket involving US 6,005,079. Searches for the number combined with "Federal Circuit," "IPR," "appeal," and the assignee returned only patent-family and citation references, no litigation docket entries. This is consistent with the record status "Expired – Lifetime" (anticipated expiration Dec. 21, 2016), which would ordinarily limit the practical value of further appellate activity.

Caveat: the tools I used are general web search, not a direct CAFC/PACER docket query. I cannot rule out a 2026 proceeding that is not indexed on the open web. If a definitive docket check is required, it should be run against the Federal Circuit's own docket system (PACER/CM-ECF) rather than inferred from these results.

Identifier caution — do not conflate with look-alikes

Per your instruction to interpret IDs literally, note that searches for the bare string "6005079" returned several unrelated documents that must not be merged with this record:

• JP 6005079 B2 (Japanese Patent No. 6005079, granted 2016-10-12) — a Mitsubishi Electric patent on a differential data generation device / mobile navigation device. Entirely different subject matter.
• Other numeric collisions (e.g., Chinese securities codes such as 600552, internal application numbers) appeared in results and are irrelevant.

Uncertainty summary

• High confidence: title, patent number, assignees, inventors, filing/issue/priority dates, application number, divisional relationship, expiration status, and the abstract — all corroborated across the authoritative full text and multiple databases.
• High confidence: verbatim text of claim 1 and claims 11–14.
• Explicit uncertainty: the verbatim text of claims 2–10 was not retrieved. The dependency references in claims 13–14 establish that claim 7 is independent, but I have not verified the exact wording of claims 2–6, 7, 8, 9, or 10, nor confirmed in the official USPTO claims listing whether any further independent claim exists.
• Explicit uncertainty: absence of 2026 CAFC activity is a negative search result, not a certified docket clearance.

I'll research litigation involving US patent 6005079. Let me run several targeted searches.

Let me dig deeper into specific US litigation and the Ablynx/Unilever/VHsquared dispute over this patent family.

Summary of Findings

No litigation naming U.S. Patent No. 6,005,079 itself was found. Based on the searches I was able to run (Google Patents, Unified Patents portal, Docket Alarm/PTAB materials, BAILII, and Dutch case databases), I could not identify any U.S. district court action, ITC proceeding, PTAB/IPR, or Federal Circuit appeal in which US 6,005,079 was asserted or challenged as an identified patent-in-suit.

I want to be explicit about a limitation: I was cut off before completing every proposed search, so this is "none found" rather than a verified negative. A definitive check would require a full Docket Navigator / PACER / Lex Machina query on the precise number.

About the patent (for context)

• US 6,005,079 — "Immunoglobulins devoid of light chains." Inventors: Cecile Casterman and Raymond Hamers. Assignee: Vrije Universiteit Brussel (VUB). Priority 1992-08-21 (EP92402326 / EP0584421A1); filed US 1995-06-06; granted 1999-12-21; anticipated expiration 2016-12-21 (status: Expired – Lifetime).
• It is one of the "Hamers patents" (the camelid heavy-chain antibody / VHH "nanobody" family), which also includes US 5,800,988 and continuations/divisions US 6,765,087, US 7,722,871, US 7,786,047, US 7,790,367, and the European member EP 1 087 013 B1.

The actual litigation in this family — it was litigated on the European members, not on '079

Worldwide enforcement of the Hamers family was concentrated in Europe (Netherlands, UK, with a Belgian jurisdiction question). Because these suits concerned EP 1 087 013 B1 and the UK designations of European Hamers patents — not the U.S. patent — I list them here as closely related, with the caveat that US 6,005,079 was not the asserted patent.

1. Ablynx N.V. v. Unilever (round 1) — Netherlands

• Plaintiff: Ablynx N.V. (exclusive licensee)
• Defendants: Unilever Nederland B.V.; Unilever Nederland Holdings B.V.; Unilever N.V.; Unilever Research and Development Vlaardingen B.V.; BAC IP B.V.
• Jurisdiction: Rechtbank Den Haag (District Court, The Hague), case no. C/09/433129 / HA ZA 12/1458
• Filed: 26 November 2012
• Patent in suit: EP 1 087 013 B1 (Hamers family)
• Outcome: District Court judgments of 4 December 2013 and 31 December 2014 (scope-of-licence "Reserved Sector" dispute). On appeal (Gerechtshof Den Haag, appeal filed 24 Feb 2015), the Court of Appeal (ECLI:NL:GHDHA:2016:3367, 7 June 2016) held Unilever had gone beyond its licence — i.e., that research on rotavirus VHH products fell inside the Reserved Sector licensed to Ablynx.

2. Ablynx N.V. v. Unilever / BAC IP — Netherlands (round 2, preliminary witness proceedings)

• Court: Rechtbank Den Haag, case no. C/09/533461 / HA RK 17-294 (petition filed 1 June 2017)
• Decision: 26 October 2018 (ECLI:NL:RBDHA:2018:13079); affirmed on appeal ECLI:NL:GHDHA:2020:1625.

3. Ablynx NV & Anor v. VHsquared Ltd & Ors — England & Wales

• Plaintiff: Ablynx NV (with the patentee/co-claimant)
• Defendants: VHsquared Ltd and others
• Jurisdiction: England and Wales High Court (Patents Court); on appeal, Court of Appeal (Civil Division)
• Case numbers: Claim form issued 4 September 2018; [2019] EWHC 792 (Pat) (Judge Hacon); EWCA Civ 2192, Case No A3/2019/0795
• Patents: three European patents with UK designations concerning camelid immunoglobulins (the Hamers patents), including EP 1 087 013 B1 — again, not US 6,005,079
• Outcome/status: The High Court rejected jurisdiction challenges; on appeal (Court of Appeal, 2019) the appeal was allowed and the UK proceedings were stayed pending a decision by the Brussels court (designated under a jurisdiction clause) on jurisdiction and on the scope of the licence. Bristows' biotech review confirms the UK action raised multiple issues (licence scope) and that enforcement was, in substance, being steered to the Belgian courts.

Key caveat for your purpose

• These proceedings involve European family members of the same Hamers/VUB invention. The licensing/ownership facts (VUB → VIB/Academic licence; Ablynx exclusive sub-licence; Unilever Licence; BAC IP; VHsquared sub-licence) establish that VUB's "patents in Europe and the US" were licensed together, so US 6,005,079 was covered by those licences as a commercial matter — but I found no record of the '079 patent being asserted in court.
• The '079 patent's U.S. term ended 21 December 2016, which is consistent with there being no recent U.S. infringement action on that specific number.

Recommendation

To give you a court-ready negative, I would run a targeted query on Docket Navigator, Lex Machina, or PACER (and the CAFC docket) limited to the exact string "6,005,079," and cross-check the VUB / VIB / Ablynx party names, plus PTAB for any IPR/PGR on the '079 number. If you authorize another search round, I can attempt those specific sources.

I'll verify the structured data against live sources before writing anything.

Let me run additional targeted searches to be thorough before concluding.

PTAB Proceedings — US 6,005,079 ("Immunoglobulins devoid of light chains")

Owner of record: Vrije Universiteit Brussel (VUB) · Inventors: Casterman, Hamers · Priority: 1992-08-21 · Granted: 1999-12-21 · Legal status: Expired – Lifetime, anticipated expiration 2016-12-21
Source of record: https://patents.google.com/patent/US6005079/en

Proceedings overview

Total AIA trial proceedings on file against US 6,005,079: zero (0) active, 0 claims invalidated, 0 claims sustained, 0 settled, 0 institution denials. The USPTO ODP structured block supplied for this task reports no AIA trial proceedings, and my independent searches of live sources (Google Patents family/litigation entries, the Unified Patents patent portal page for US-6005079-A, and docket aggregators) surfaced no IPR, PGR, or CBM naming this patent — see "Searches run and what they did not show," below. The defensive posture this yields is not "hardened by adverse PTAB testing" but rather "untested at the PTAB and, more importantly, expired": the safest defense here is not an IPR but the patent's own term, which ran out on 2016-12-21. Before relying on that, verify the expiration computation against the face of the patent and the PTO Patent Center record, because term questions turn on the pre-URAA/URAA line and any terminal disclaimer or PTA.

Bottom line for a defendant: no PTAB proceeding has ever narrowed these claims, so there is no FWD to point to and no § 315(e)(2) estoppel to invoke. But there is also no live patent term to be enjoined under (subject to verification), which in practical terms beats any IPR outcome. Treat any demand letter citing US 6,005,079 as a historical-damages-only problem, if it is a problem at all.

Per-proceeding detail

None. There are no proceeding numbers to report, and I will not manufacture any. The required template (### {PROCEEDING_NUMBER} — {Petitioner} v. {Patent Owner}) has no instances for this patent.

Searches run and what they did not show

I ran six targeted queries. The results were uniformly negative for this patent:

Conflation warning (important). The 2026 Federal Circuit appeal by Ablynx N.V. and Sanofi is an obviousness-type double patenting appeal arising from prosecution of application 17/409,019 (a Nanobody fusion-protein family claiming priority to PCT/EP2012/062251), affirmed by the Board on ex parte appeal and now briefed at the Federal Circuit (brief hosted at https://patentlyo.com/media/2026/08/Ablynx-USPTO-Brief.pdf). That is an ex parte appeal from examination — it is not an AIA trial, and it does not involve US 6,005,079. Do not cite it as PTAB activity against this patent.

Similarly, the extensive VUB/Ablynx activity at the European Patent Office (oppositions against EP 1 641 822, with Ablynx, Merck Patent GmbH, Novartis, Janssen Biotech, and a third party as opponents) is not PTAB activity, though it is a useful reminder that Ablynx/VUB patents have been contested hard overseas. Note also the practical asymmetry: Ablynx was an opponent in several of those EPO matters, i.e., it litigates IP aggressively in both directions in Europe.

Strategic summary

Cancelled vs. sustained vs. untested. There is no claim-level PTAB record for US 6,005,079, so every claim is UNTESTED before the Board. No claim has been cancelled, and none has been upheld in an FWD. If someone represents otherwise — for example in a demand letter or an invalidity opinion that cites "the IPR decision on the '079 patent" — that representation is false, and the absence of any such decision is verifiable in seconds on PTAB E2E. I have deliberately not enumerated the claims or their dependency structure, because I could not verify the claim set from a primary document and will not guess; pull the claim text from the Google Patents page or Patent Center before drafting anything claim-specific. (The abstract on the face of the patent — "an isolated immunoglobulin comprising two heavy polypeptide chains sufficient for the formation of a complete antigen binding site or several antigen binding sites, wherein the immunoglobulin is further devoid of light polypeptide chains" — tracks the invention's core claim language closely, but I am not asserting that this is verbatim claim 1.)

Estoppel landscape. Because no IPR, PGR, or CBM was ever instituted, § 315(e)(2) estoppel attaches to no one. There is no petitioner-and-privies class barred from re-raising grounds, and there is correspondingly no "clean" set of grounds carved out for a defendant. Any prior-art ground you can find — including art that a hypothetical earlier petitioner raised or could have raised — remains fully available to you in district court, subject only to ordinary § 102/§ 103, Rule 11, and IPR-filing mechanics. One mechanical constraint to keep in mind: § 315(b)'s one-year bar is triggered by service of a complaint alleging infringement; absent any complaint, no bar runs. And § 315(a)(1) bars an IPR filed by a petitioner that previously filed a civil action challenging validity of the same claim.

Expiration is the dominant fact. The patent's legal status on the record is "Expired – Lifetime," with anticipated expiration 2016-12-21. That date is consistent with the pre-URAA rule (application 08/471,284 filed 1995-06-06, before the June 8, 1995 URAA line): term is the greater of 17 years from grant (1999-12-21 → 2016-12-21) or 20 years from the earliest U.S. filing date (parent 08/106,944, filed 1993-08-17 → 2013-08-17). The grant-plus-17 date controls. Consequences: (i) no prospective relief for post-2016-12-21 conduct; (ii) damages exposure, if any, is confined to infringement occurring before expiration and is independently cut back by the § 286 six-year limitation; (iii) the patent is a fully public prior-art document, usable as § 102 art against later filings in the nanobody/single-domain-antibody space — which is a more valuable defensive use today than an IPR would have been. This is the classic situation where a defendant's best move is a § 101/§ 102/§ 112 or standing/expiration-based dispositive motion rather than a PTAB petition.

Pattern signals. (1) No petitioner has ever filed multiple IPRs against this patent — in fact, no petitioner has filed one. (2) No defensive aggregator appears in the chain. The Unified Patents portal maintains a record page for US-6005079-A (https://portal.unifiedpatents.com/patents/patent/US-6005079-A), but nothing there indicates a Unified-filed challenge, and no Unified IPR on this patent exists on any record I could find. (3) The patent owner has not pursued PTAB appeals on this patent — there are none to pursue. (4) The patent is heavily cited as prior art by later antibody/VHH filings in both the US and EPO, consistent with its status as a foundational but long-since-lapsed disclosure.

Recommended next steps

1. Verify expiration before anything else. Pull the Patent Center record (https://patentcenter.uspto.gov) and confirm the expiration date, any terminal disclaimer, and any PTA. If the patent is expired, the entire dispute is past-damages-only, and the § 286 six-year window plus any laches/notice arguments (§ 287 marking) are likely dispositive or near-dispositive.

2. Confirm the no-PTAB fact directly on PTAB E2E — search by patent number at https://ptacts.uspto.gov/ptacts/ (and, for older records, the PTAB Decisions archive). This takes under a minute and converts an "absence of evidence" into a citable fact you can put in a brief or a Rule 11/Civil Rule 11 pre-motion letter.

3. Say it plainly in any response to an assertion. The correct framing is: "There have been zero AIA trial proceedings against US 6,005,079. No claim has been cancelled, and none has been upheld — the claims are simply untested, and the patent expired on 2016-12-21. Any infringement theory directed at post‑expiration conduct fails as a matter of law."

4. If there is a genuine pre-2017 damages theory, then attack validity in district court, not the PTAB. With no estoppel and no institution history, you are free to run any § 102/§ 103 combination, plus §§ 101 and 112 challenges that the PTAB could not have reached in an IPR (IPR is limited to §§ 102/103 on patents and printed publications; PGR is unavailable for a patent with a 1992 priority date, and CBM is unavailable post-SAS/under § 18 sunset for a patent of this vintage and subject matter). A district court is the only forum where the full invalidity toolkit is available for this patent.

5. Use the patent affirmatively. US 6,005,079's 1999 specification and its FIG. 7 VHH sequence alignments are prior art against later single-domain-antibody claims. If you are being asserted against on newer nanobody patents (e.g., Ablynx/Sanofi portfolios), this patent is a strong § 102/§ 103 anchor — potentially a more useful IPR exhibit elsewhere than as an IPR target here.

6. Preserve the record. Save the Google Patents page as of today (2026-09-20) and screenshot the PTAB E2E null result. Legal-status fields and third-party portals can change presentation over time, and a dated snapshot of "no proceedings, expired" is cheap insurance.

Reliability caveats, stated explicitly:

• I did not obtain a primary PTAB document either way; the conclusion "no proceedings" rests on the ODP structured block (canonical per the task framing) plus negative results from multiple independent searches. Negative search results are weaker evidence than a positive hit, but here the ODP record and the search results agree, which is the strongest form of the "no activity" conclusion available short of a manual E2E retrieval.
• If a proceeding exists that is recent enough or obscure enough to be absent from both ODP ingest and web indexes, it would be a newly filed matter — a petition filed within roughly the last few weeks. I found no evidence of one, and for a patent that expired in 2016 and has never been IPR'd, that would be surprising.
• Claim numbers, claim counts, and dependent-claim structure for US 6,005,079 are not stated above, because I could not verify them from a primary document. Do not infer them from this report.

I'll research the assignment record for US 6,005,079 through the USPTO Assignment Center and related sources.

Let me dig into the US-specific assignment records and the Google Patents legal events for this patent.

Inventors

Patterns: No unusual departure pattern. Both inventors were VUB academic staff and assigned to their employer (a university) — the normal academic tech‑transfer route. There is no evidence of inventors leaving the assignee within 12 months of filing, no serial‑inventor‑shell pattern, and no indication of a pre‑sale portfolio vacuum. The inventors remained VUB‑affiliated (Casterman and Hamers are named on later VUB-owned family members such as US 7,655,759 and US 7,786,047). This is the opposite of the classic "inventors bail, portfolio is fire‑sold" signature.

Original assignee

Vrije Universiteit Brussel (VUB) — Pleinlaan 2, 1050 Brussels, Belgium.

• Entity type / line of business: a public (Dutch‑speaking) university; core business is higher education and academic research, not manufacturing.
• Product embodying the claims: No. VUB is a university and does not commercialize antibodies. However, the underlying Hamers/VHH technology was licensed (exclusive licence) into Ablynx N.V., a VUB spin‑out (founded ~2001), which developed the single‑domain "Nanobody" platform and commercialized caplacizumab (Cablivi®), approved in the EU (2018) and US (2019). Ablynx was subsequently acquired by Sanofi (announced January 2018, ~€3.9 bn). Caveat: I did not verify these corporate events against SEC/company filings in this pass; treat the Ablynx/Sanofi detail as background, not as a recorded USPTO assignment fact. Critically, VUB — not Ablynx — remained the assignee of record on '079; Ablynx's position was licensee, not assignee.
• Current status: Operating. VUB is a solvent, ongoing public university. Not acquired, not dissolved, not in bankruptcy. No Chapter 7/11 analogue exists in the chain.

Assignment timeline

Retrieval limitation (state this plainly): my available tooling in this pass was general web search, not a direct transaction against assignmentcenter.uspto.gov. I therefore have the event for the assignment (via Google Patents Legal Events, which mirrors the recorded event) but not the reel/frame number, the correspondent of record, or the exact execution date. I did not fabricate those fields. The reel/frame for even the single recorded link below should be pulled directly from the Assignment Center search by patent number before this is treated as a certified chain‑of‑title.

Recorded assignments found

1. Recorded 1996‑12‑26 — Reel/Frame not retrieved (Assignment Center query not available to me in this pass)
   • Conveyance: Assignment — recorded as "ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS)"
   • Assignor: CASTERMAN, CECILE; HAMERS, RAYMOND
   • Assignee: VRIJE UNIVERSITEIT BRUSSEL
   • Correspondent: not retrieved. (Lead, not a finding: the correspondence address on the '079‑family continuation US 2007/0077240 A1 (Ser. No. 11/350,900) is Wolf, Greenfield & Sacks, P.C., Federal Reserve Plaza, 600 Atlantic Avenue, Boston, MA 02210‑2206. That is a prosecution‑correspondence address on a later family member, not confirmed as the assignment‑recording correspondent for '079. Single appearance — do not treat as a repeat‑correspondent signal.)
   • Context: inventor‑to‑employer assignment (university tech transfer). Ordinary and expected.
   • Date ambiguity flag: Google Patents renders this as an event dated 1996‑12‑26. For assignment events this is generally the recording date; the execution date is not distinguished in the source I have. Do not report 1996‑12‑26 as the execution date without pulling the document image.

Assignments NOT in this chain (do not conflate)

• Reel 020627/0605 — "ASSIGNMENT OF ASSIGNORS INTEREST; ASSIGNOR: CONOPCO, INC.; effective 2006‑02‑03" to BAC IP B.V. This recording appears on the Legal Events page of US 7,794,981 B2 ("Production of antibodies or (functionalized) fragments thereof derived from heavy chain immunoglobulins of Camelidae"), which is the Unilever/CONOPCO family (EP 0 698 097). It is not an assignment of US 6,005,079. Confirming this from a second register: the Irish Patent Register shows, for EP 0 698 097, "Assignment from co‑proprietors VRIJE UNIVERSITEIT BRUSSEL … and UNILEVER PLC … to BAC IP B.V. … by virtue of a Deed of Assignment dated 06/02/2006." Same effective date, same assignee, different patent.
• Finding: no recorded assignment of US 6,005,079 to BAC IP B.V., Ablynx N.V., Sanofi, or any other entity was found. The '079 chain appears to terminate at VUB.

Bottom line on the timeline: exactly one recorded conveyance — the 1996 inventor→VUB assignment — and nothing thereafter. That is itself the finding: the original assignee (a university) still owns the patent.

Timeline diagram

timeline
    title Ownership of US 6005079
    1992 : Priority EP 92402326
    1993 : Parent app 08 106 944 filed
    1995 : Divisional app 08 471 284 filed
    1996 : Inventors assign to VUB
    1999 : Patent granted
    2016 : Patent term ends

NPE / troll-pattern signals

Verdict

Insufficient data

Justification: the USPTO record contains only the original inventor→assignee assignment (recorded 1996‑12‑26: CASTERMAN, CECILE and HAMERS, RAYMOND → VRIJE UNIVERSITEIT BRUSSEL, "ASSIGNMENT OF ASSIGNORS INTEREST"), with no subsequent recorded conveyance, so the chain terminates at a solvent public university that does not manufacture. That is the "only the original assignment" branch of the rubric, and it drives the verdict — not an NPE finding. Every one of the eight NPE signals is not present (or, for correspondent recurrence, not assessable on a one‑link chain), and the one look‑alike recording that could muddy this analysis — CONOPCO, INC. → BAC IP B.V., Reel 020627/0605, effective 2006‑02‑03 — belongs to US 7,794,981 B2 / EP 0 698 097, not to '079.

Two caveats that cap the confidence:

1. I could not reach assignmentcenter.uspto.gov directly in this pass, so I have not verified the reel/frame, execution date, or correspondent of record for the 1996 entry, nor formally ruled out an unindexed post‑1996 recording. Verify at: https://assignmentcenter.uspto.gov/ (search by patent number 6005079) — mirror index at https://assignment.uspto.gov/patent/index.html.
2. "Insufficient data" here means insufficient record data, not "suspicious." The affirmative commercial fact — a VUB exclusive licence into the Ablynx spin‑out, enforced in Europe against Unilever/VHsquared on the European family members — is a university/operating‑licensee pattern, which is neither an NPE pattern nor a classic competitor‑on‑competitor assertion. Do not let the verdict label imply a troll signal that the reel/frame evidence does not support.

Recommended next step for a court‑ready record: pull the Assignment Center entry for patent 6005079 to capture reel/frame, execution vs. recording dates, and the correspondent of record; then run the same query across the sibling cases (US 5,759,808; US 5,800,988; US 5,840,526; US 6,765,087; US 7,722,871; US 7,786,047; US 7,790,367) to confirm whether the VUB chain is clean across the whole family or whether any sibling was separately conveyed.

I'll research the prior art citations on US 6,005,079. Let me run targeted searches.

Let me retrieve the front-page "References Cited" list and the patent PDF directly.

Let me pull the front-page "References Cited" and "Referenced By" listings from FreePatentsOnline and the EPO register for this exact patent.

Prior-art analysis — US 6,005,079 A ("Immunoglobulins devoid of light chains")

Bottom line up front: I ran the search against the authoritative full text you supplied plus Google Patents (https://patents.google.com/patent/US6005079/en), FreePatentsOnline (https://www.freepatentsonline.com/[6005079](/patent/6005079).html), and the Unified Patents portal (https://portal.unifiedpatents.com/patents/patent/US-6005079-A). I could not retrieve the verbatim front-page "References Cited" block (U.S. Patent Documents / Foreign Patent Documents) for US 6,005,079 itself — the supplied full text begins with the description, not the front page, and the tools available returned the citation lists of sibling family members (EP 1589107 A1 / EP 05008358; EP 2 311 941; EP 2 902 494) rather than the US '079 front page. I flag this as an unresolved gap rather than reconstruct a list. Everything below is either (i) a reference literally appearing in the authoritative text of this patent, or (ii) a reference retrieved from the family's citation lists, labelled as such.

Also, per your strict-ID rule: the string "6005079" collides with JP 6005079 B2 (Mitsubishi Electric, differential data generation device), a City of Detroit contract no. 6005079, and several securities codes. None of those are US 6,005,079 and are excluded.

1. Identification of the patent (verified)

Governing statute: pre-AIA 35 U.S.C. § 102 (application filed 1995). Assuming benefit of the 1992-08-21 foreign priority, the critical dates are:

• § 102(b) statutory bar: public disclosure before 1991-08-21 (one year before the priority date).
• § 102(a): public knowledge/use/publication before the invention date.
• § 102(e): U.S. patent/application with an earlier effective filing date.

2. Patent documents associated with US 6,005,079

I could not recover a definitive "U.S. Patent Documents" list from the '079 front page. The patent documents I did identify in or around this record are family members, and none can be § 102 prior art because they share the same VUB inventors and the same 1992 priority.

The face of the record shows 488–619 "Cited By" documents (US 10,759,855; US 10,696,745; US 10,927,180; WO 2004/081026; WO 2004/091510; US 6,838,254; etc.). Those are forward citations (later patents citing '079) and are not prior art to '079. They are frequently mislabeled as "citations"; do not use them in a § 102 analysis.

3. Non-patent literature cited in/for US 6,005,079

The following are the references actually appearing in the specification text or in the family's citation lists (Unified Patents lists ten NPL items; the EPO sibling list adds more). Each is tagged [SPEC] if quoted in the '079 description itself, or [EP-LIST] if taken from the family's EPO citation list.

4. Direct answer: which references "potentially anticipate" which claims

Applying pre-AIA § 102 strictly, no cited reference — patent or non-patent — anticipates the principal claims of US 6,005,079:

• Claim 1 (two heavy chains, each bearing a complete antigen-binding site; VHH + constant region; constant region lacking CH1; devoid of light chains). No reference discloses all four elements simultaneously. Ward (1989) has VH domains but needs VL and retains the VL interface; HCD (Seligmann 1979) lacks light chains but lacks a functional complete binding site and is a pathogenic deletion mutant; Roitt teaches the four-chain model. No anticipation. Ward and Seligmann are the two references a challenger would pair under § 103.
• The variable-region / fragment claims (my reconstruction of claims 7–12, including the isolated VHH of claim 12 and the CDR3/position-45 fragment of claim 11): Ward 1989 is the most relevant art, but its domains are four-chain VH domains, not light-chain-free VHH fragments, and it does not disclose the charged residue at position 45 (Arg/Glu/Cys) that the claims require. The Schiffer DAW protein is the only cited molecule with an intra-V-region disulfide, but it is a human four-chain myeloma protein, not a fragment of a light-chain-free immunoglobulin. No anticipation; § 103 exposure only.
• The IgG2/IgG3 subclass claims (my reconstruction of claim 14): the cited art does not describe camelid γ2/γ3 heavy-chain subclasses. No anticipation.
• Dictionary (Webster's 1995) and the Hamers-Casterman Nature paper (1993) are outside the § 102 window and cannot be prior art — they appear only as claim-construction and enabling-disclosure matter respectively.

The defensible characterization of the cited art: it is overwhelmingly background / method art (§ 102(b) printed publications combined with ordinary skill), i.e., potential § 103 material, not § 102 anticipation material. For any § 102 challenge to succeed against the core claims, a reference would need to disclose a naturally occurring two-heavy-chain, light-chain-free immunoglobulin with a complete antigen-binding site and no CH1 — which none of these do. That gap is precisely the novelty that the Hamers family (including US 5,759,808 / 5,800,988 / 5,840,526) reflects.

5. Confidence and explicit uncertainties

• High confidence: patent identity/dates (US 6,005,079 A, priority 1992-08-21, filed 1995-06-06, issued 1999-12-21); the NPL set reproduced above; Ward 1989, Roitt, Blier 1987, Hamers-Casterman 1993, Webster's 1995 are genuinely associated with this record.
• High confidence: the family-member patents and WO 94/04678 are not § 102 prior art (common inventorship/priority).
• Explicit uncertainty — the key one: the verbatim USPTO front-page "References Cited" (U.S. Patent Documents and Foreign Patent Documents) for US 6,005,079 was NOT retrieved. I could not confirm whether the USPTO front page lists zero, one, or several U.S. patent documents (the Unified Patents record shows "Patent Art (1)"), nor the exact foreign-document list. The non-patent list from the EPO sibling (items 6–22) is offered as the family's citation list, not certified as the '079 U.S. front page. A definitive § 102 table requires a direct pull of the '079 front page from USPTO Patent Public Search / PatentCenter, or the granted-PDF page 1.
• Explicit uncertainty: the date/content of items 17, 18, 19 (Ungar-Waron 1987; Badyana Songa 1988; Edelman PNAS 50:753) were inferred from the EPO list and bibliographic memory and were not independently verified in the searches run.
• Explicit uncertainty: the claims-analysis maps to the claim-numbering I reconstructed earlier (claim 1 = two-chain immunoglobulin; claim 7 onward = fragments; 11 = position-45 fragment; 12 = VHH; 14 = IgG2/IgG3). Verbatim claims 2–10 remain unverified, so the anticipation mapping is by claimed subject matter, not by certified claim text.

Recommended next step for a court-ready table: pull the granted PDF of US 6,005,079 (page 1) from USPTO PatentCenter/Patent Public Search for the exact "References Cited" and "Foreign Patent Documents," and cross-check each against the § 102 critical date of 1991-08-21. If you authorize another search round, I can target the patentimages.google front page and the USPTO Public Search API directly.

I'll research the prior art landscape for this patent before building the § 103 analysis.

Let me pull the exact claim language for '079 (the earlier section flagged claims 2–10 as an unresolved gap) and check the key obviousness references.

Obviousness Analysis — US 6,005,079 under 35 U.S.C. § 103

Scope note / contradiction flag. The current task states "Current Date: April 26, 2026," while the previously generated sections (and the page fetch timestamp) are dated 2026‑09‑20. I flag the discrepancy rather than silently reconciling it. Also, per the earlier section, the verbatim text of claims 2–10 was never retrieved; I obtained claim 11 verbatim this round (FreePatentsOnline, https://www.freepatentsonline.com/[6005079](/patent/6005079).html) but claims 2–10 remain unverified. Everything below that depends on claim 1's wording is therefore based on the RPX rendering recorded in the prior section and is flagged as reconstruction, not quotation.

1. Legal framework and the effective date

Standard: Graham v. John Deere, 383 U.S. 1 (1966); KSR Int'l v. Teleflex, 550 U.S. 398 (2007) (predictable variations, "obvious to try" where the number of identified, predictable solutions is small, design incentives/market forces). Motivation may flow from "the nature of the problem to be solved" (In re Kemps; KSR), and a reference must be read for what it fairly teaches, not for what it fails to say.

Critical § 103 date-management point (often missed in this family):

• Hamers‑Casterman et al., Nature 363:446–448 (1993) is not prior art. It published 1993‑06‑03, i.e. after the 1992‑08‑21 priority date and within the § 102(b) grace year counted from the 1993‑08‑17 U.S. filing. It is also the inventors' own work, so it is neither 102(a) "by others" nor 102(e). The same is true of the Casterman family patents that appear on the "Referenced Cited" list of later family members (US 5,759,808; 5,800,988; 5,840,526; 5,874,541; 6,015,695) — same inventive entity, not § 102(e) art.
• The only Hamers-family material that can be prior art is the Belgian/EP priority disclosure itself, and only via § 102(e)/§ 119-style routes, not for § 103 support in the ordinary way.
• Everything else in the "References Cited"/prior-art section below does qualify.

2. The prior art actually available (the "Prior Art" section material)

2.1 References of record on the face of '079 and its siblings

From the FPO/Google Patents/Unified Patents records for '079 and the co-pending siblings US 5,759,808 and US 5,840,526 (https://portal.unifiedpatents.com/patents/patent/US-6005079-A; https://patentimages.storage.googleapis.com/10/83/e0/f22fdc9d55a019/US5759808.pdf; https://patentimages.storage.googleapis.com/e9/c7/90/840d4374e2ac1d/US5840526.pdf):

2.2 Prior art cited in the sibling European members (EP 1 087 013 / EP 1 589 107 citation list; https://patents.google.com/patent/US20060121026 and the EP citation listing retrieved above)

These are the references the Examiner/EPO treated as the technical background, and they are the backbone of any § 103 case:

3. Claim 1 — element-by-element obviousness

Claim 1 (as reported in the prior section; wording flagged as reconstruction, RPX rendering contains the typographical error "fist" for "first"): an isolated immunoglobulin comprising two heavy polypeptide chains, each heavy chain bearing its own antigen-binding site sufficient for a complete binding site, having a variable (VHH) region and a constant region, the constant region lacking CH1, and the molecule being devoid of light polypeptide chains.

Proposed Combination A — Ward '89 + Seligmann '79 (+ Franklin/Brandt) + Hendershot '87/'90 + Fleischman '62/Roholt '64 + Roitt

Motivation to combine. KSR holds that an express suggestion in the art is not required; the "nature of the problem" suffices. Here Ward supplies an express suggestion: he reports that VH domains bind antigen, that they are sticky because their hydrophobic surface is normally capped by VL, and that it "should be possible to design VH domains having improved properties," with VH binding domains as building blocks. Hendershot supplies the mechanistic key: CH1 is the BiP docking site, so a heavy chain without CH1 will be secreted without needing a light chain. Fleischman/Roholt supply the complementary reason a skilled artisan would want to remove the light-chain dependence (aggregation/solubility). Seligmann supplies the existence proof that a secreted, two-heavy-chain, light-chain-free, CH1-deleted immunoglobulin is a real molecule in a mammal. A skilled artisan seeking a smaller, light-chain-independent antigen-binding immunoreagent — and able to produce it in E. coli (Plückthun '90; Huse '89; Sastry '89) without the BiP/CH1 secretion block — would have had every reason to construct a CH1-deleted heavy-chain dimer bearing Ward-type VH binding domains.

Reasonable expectation of success. Deliberately deleting CH1 from an Ig heavy chain was a routine, predictable manipulation by 1992 (Brandt '84 had already shown the natural route via splice-signal loss, and Hendershot had defined the phenotype). The artisan would expect a CH1-minus heavy chain to (i) be secreted without light chain and (ii) have its VH domains available for antigen binding. That is precisely claim 1.

Weakness of Combination A (the crux). The claims require a heavy chain "sufficient for the formation of a complete antigen binding site." The specification itself distinguishes the invention from heavy-chain disease proteins, stating they are "monoclonal in origin and result from pathogenic mutations… They have apparently no antigen binding site," and that HCD heavy chains "carry deletions in the CH1 and VHH domains" (full text, https://patents.google.com/patent/US6005079/en). Ward's VH domains, in turn, were sticky, aggregation-prone, and had to be rescued by light chain — Ward teaches the problem, not a solution in a two-chain molecule. So the combination asks the artisan to combine a molecule that (a) binds nothing (HCD) with a molecule that (b) does not work well without VL (Ward). Whether a POSA would have had a reasonable expectation that the combination would actually yield a functional, soluble, non-aggregating, light-chain-free antigen binder — rather than an aggregated dead-end — is genuinely contestable. That is the strongest non-obviousness argument on the record.

4. Claim 11 — the position-45 limitation

Claim 11 (verbatim, FPO): "A fragment of the variable region of the heavy polypeptide chain of the immunoglobulin according to claim 1, which comprises a CDR3 domain and includes the amino acid residue corresponding to position 45 of said heavy polypeptide chain wherein said amino acid residue is selected from the group consisting of charged amino acids, and a cysteine residue, wherein said fragment comprises a binding site specific for an antigen."

Proposed Combination B — Ward '89 + Chothia '85/'87 + Kabat '87 (+ Schiffer '73 "DAW")

• Ward expressly frames the VH solubility problem as the exposed hydrophobic surface normally capped by VL, and expressly proposes "design[ing] VH domains having improved properties." That is a direct, art-recognized invitation to modify the VH/VL interface.
• Chothia '85 ("The packing of variable domains") maps that interface and identifies the framework-2 region, including position 45, as a principal VL-contacting residue. Kabat '87 supplies the numbering convention the claim uses. The two together make "position 45" an obvious target: it is the single most conspicuous VL-contacting framework residue.
• The claim's two alternatives each have independent art support:
• charged residue — Ward's own therapy (replace an exposed hydrophobic side chain with a hydrophilic/charged one); the '079 specification acknowledges leucine at 45 in 98% of four-chain VH, "the other amino acids at this position being proline (1%) or glutamine (1%)" — the artisan's starting point and the reason a charged substitution is the natural move.
• cysteine — the specification itself concedes that the CDR3–FW2/CDR1 disulfide is known in the DAW myeloma protein (Schiffer et al. 1973), which is squarely prior art.

Motivation to combine: to make a VL-free VH domain soluble and stable — the exact problem Ward posed. Expectation of success: substituting a hydrophilic residue at a known hydrophobic interface position is a routine, structure-driven design choice, i.e. a "predictable variation" under KSR. This is the most obviously-attackable limitation in the patent, because the specification's own text hands the challenger both the baseline (98% leucine) and the single precedent (DAW).

Rebuttal: 98%+ conservation of position 45 across all four-chain VH repertoires is prima facie evidence that the position is functionally constrained — a mutation there would ordinarily be expected to destabilize the domain's packing. And the claim does not merely require a charged residue; it requires a fragment of a claim-1 immunoglobulin with an antigen-specific binding site, so the artisan must first have the claim-1 molecule. If claim 1 is non-obvious, claim 11 falls with it (dependent claim). Conversely, if claim 1 is held obvious, claim 11 is likely to fall too.

5. Claims 12–14 and the fragment claims (7–10)

• Claim 12 (verbatim): "The variable region (VHH) of the immunoglobulin according to claim 1." Purely dependent in substance — an isolated domain of the claim-1 molecule. Its fate is fully derivative of claim 1. Note that Ward '89 already isolates single VH domains as a composition, so if the claim-1 molecule is obvious, claim 12 is obvious over Ward '89 alone.
• Claim 13 (verbatim): fragment "wherein each variable region of each heavy chain polypeptide contains binding site specific for an antigen." A homodimerization/vale convention (Seligmann '79 shows heavy chain homodimers; IEF reduction/alkylation data in the specification confirm two identical chains).
• Claim 14 (verbatim): fragment "which is a type G immunoglobulin of class 2 (IgG2) or… class 3 (IgG3)." An obvious species of an obvious genus; moreover the subclasses were separable by routine Protein A/Protein G differential elution (Harlow & Lane '88; the '079 Examples themselves use exactly that routine to resolve IgG2/IgG3). Under KSR, where a genus is obvious, contemporaneous discovery of species within it is generally not a separate inventive act. Counterpoint: In re Baird / product-by-species reasoning aside, the subclasses are defined by hinge length and a Pro‑X repeat not suggested by the art (SEQ ID NO:38, the IgG2 long hinge), which cuts mildly toward non-obviousness for claim 14 as to IgG2.
• Claims 7–10 (unretrieved). Claims 13 and 14 both recite "according to any one of claims 7, or 8 to 12," confirming claim 7 is independent. Read with the specification, claim 7 is almost certainly a fragment claim (single heavy chain; papain-derived FVHHh or F(ab')₂ analog; Fc/pFc; the Pro‑X hinge fragment). If so, obviousness follows if claim 1 is obvious: papain/pepsin digestion of immunoglobulins was routine and textbook (Roitt '85/'89; Fleischman, Pain & Porter '62), and the specification's entire fragment nomenclature is simply the standard digestion nomenclature "renamed" because Fab/Fd/Fv "are no longer applicable." An obvious composition carries its obvious fragments. This is the weakest part of the non-obviousness case, but I cannot verify claim 7's wording — flagged as unresolved.

6. The camelid-specific limitation (the real battleground)

Claim 1 as reported is not explicitly limited to camelids, but the '079 claims and specification are read against a background in which the only enabling disclosure is the camelid molecule; the record prior art (Ungar‑Waron '87; Grover '83) shows camel IgG to be anomalous.

Proposed Combination D — Ward '89 + Ungar‑Waron '87 + Grover '83 + Sastry '89/Huse '89 + Protein A/G chromatography (Harlow & Lane '88)

The Examiner/defendant's case: Ungar‑Waron and Grover had already partially characterized dromedary IgG and noted unusual features (a ~100 kD IgG species); the artisan, motivated to find new antibody sources and to exploit Ward's single-domain concept, would have purified and fractionated camel serum IgG by routine Protein A/G chromatography and cloned the VH repertoire using Sastry‑type primers. Under KSR's "obvious to try" language, screening a known-anomalous species with routine tools is an obvious design choice; the result (a CH1-deleted two-chain IgG) would be recognized once isolated.

Why this fails, in my view: This is impermissible hindsight. Ungar‑Waron and Grover do not disclose, suggest, or enable a light-chain-free immunoglobulin. Critically, they do not even correlate the anomalous 100 kD species with the absence of light chains. The "obvious to try" doctrine requires a finite number of identified, predictable solutions with a reasonable expectation of success; here the artisan had no reason to expect that a healthy camel produces a functional, light-chain-free, CH1-deleted antibody, because:

1. The art taught away. Ward '89 taught VH domains are "relatively sticky" and aggregate; Fleischman '62 and Roholt '64 taught isolated heavy chains aggregate and are only solubilized by light chains binding CH1; Hendershot '87/'90 taught heavy chains lacking light chain are retained by BiP. The uniform teaching was that a heavy-chain-only, VL-free antibody should not exist in a healthy animal and should not be soluble. The camel molecule is the exception the art predicted could not occur outside pathology.
2. The pathology/malignancy distinction. The only heavy-chain-only immunoglobulins known (Seligmann '79 HCD; the DAW protein) arose from pathogenic somatic deletion in monoclonal lymphoproliferative disease and had no demonstrable antigen-binding site. Nothing in the art suggested a germline, non-pathological, repertoire-bearing heavy-chain antibody.
3. Structure was not predictable from the sequence. The functional unit of claim 1 required (i) a VHH that folds and stays soluble without VL and (ii) an unexpectedly charged/hydrophobic-residue-shifted framework-2 (position 45) and a CDR3–CDR1/FW2 disulfide that compensate for the lost VL interface. Neither was derivable; it was deduced after isolating the molecule.
4. Unpredictable property demonstrated. The claims are supported by a genuinely unexpected result — the molecule is non-sticky and soluble above 0.5/1/2 mg/ml, in direct contradiction to Ward's teaching about VH domains, and it occurs in a normal, healthy animal. In re Soni / secondary-considerations framework supports weighing this.

7. The purified-natural-product question

Claim 1 is, in substance, a claim to a naturally occurring composition of matter that was previously unknown to exist. The controlling line — In re Bergstrom, 427 F.2d 1394 (CCPA 1970) (purified prostaglandins patentable because the prior art did not disclose their existence or structure); In re Kratz (CCPA) — holds that where the prior art neither discloses nor makes available the claimed compound, a purified form is non-obvious notwithstanding the availability of routine purification techniques. The camelid heavy-chain IgG is the paradigm case: camel serum was commercially available, Protein A/G chromatography was routine, yet nobody had ever obtained or recognized the molecule in 10+ years of camel IgG work (Grover '83; Ungar‑Waron '87). The long-felt, unfulfilled need is itself evidence of non-obviousness.

This is strengthened by In re Deuel, 51 F.3d 1552 (Fed. Cir. 1995) if any claims read on DNA/nucleotide sequences (the '079 specification contains nucleotide-sequence and primer claims material at SEQ ID NOs 47–53). Deuel's reasoning has been narrowed post-KSR, so I would not rely on it heavily.

8. Bottom line

The single dispositive question for the whole patent is claim 1. Every other claim is either dependent on claim 1 or is a routine fragment/species of it. If a challenger can prove that, as of 1992‑08‑21, a POSA would have had a reasonable expectation that deleting CH1 from a Ward-type VH-bearing heavy chain would yield a functional, soluble two-chain antigen binder, the patent is largely exposed. If the challenger cannot — and the Ward "sticky VH" teaching, the Fleischman/Roholt aggregation teaching, and the Hendershot BiP retention teaching all point the other way — then claim 1 survives and the dependent claims survive with it.

9. Explicit uncertainties and methodology caveats

1. Claims 2–10 remain unretrieved verbatim. I verified claim 11, 12, 13 and 14 this round from FreePatentsOnline (https://www.freepatentsonline.com/6005079.html). Claim 1 is used as recorded in the prior section (RPX rendering). The assertion that claim 7 is an independent fragment claim is inferred from the "any one of claims 7, or 8 to 12" dependency in claims 13/14 — it has not been confirmed against the USPTO claims listing. Do not treat my § 5 fragment analysis as claim-verbatim.
2. Reference dates. Ward '89, Seligmann '79, Hendershot '87, Fleischman '62, Roholt '64, Schiffer '73, Chothia '85/'87, Kabat '87, Sastry '89, Huse '89, Marks '91, Harlow & Lane '88, Ungar‑Waron '87 and Grover '83 all predate 1992‑08‑21 and qualify. Hamers‑Casterman Nature 363:446 (1993) does not, and must not be used as § 103 art in this case despite its prominence on the face of the family.
3. No U.S. validity challenge is on record. Per the earlier litigation section, I found no § 103 challenge to '079 in any U.S. district court, PTAB/IPR, or Federal Circuit proceeding; the family was litigated on its European members (Ablynx v. Unilever; Ablynx v. VHsquared). The '079 patent expired 2016‑12‑21, so this analysis is retrospective.
4. This analysis is a two-sided advocacy map, not a prediction. I have given the challenger's best combination for each claim and the patentee's best rebuttal. Where the two sides are close (claim 1), I say so rather than forcing a conclusion.