US 6268053

I'll search for current docket and litigation information, then compile the summary.

US 6,268,053 B1 — Analyst Summary

Scope note / number literalism. I searched USPTO-derived and public docket sources for the literal number 6268053. Several other identifiers collide with that digit string and must not be conflated with US 6,268,053:

The entity in the search hits that does refer to US 6,268,053 is the Epic Therapeutics / Baxter "macromolecular microparticles" family (cited as prior art in later filings such as the EP 2,774,935 A1 and RU 2,457,854 C2 references I retrieved).

Bibliographic data (per the Google Patents record)

Continuity chain (from the specification): 09/483,657 is a continuation of 08/699,586 (filed 1996-08-19, now US 6,090,925), which is a continuation-in-part of 08/206,456 (filed 1994-03-04, now US 5,578,709), which is a continuation-in-part of 08/028,237 (filed 1993-03-09, now abandoned). This family is the reason the '053 specification appears nearly verbatim in sibling U.S. patents and in EP 0 688 429 B1 / EP 0 809 110 A1.

Abstract

"Microparticles formed by mixing a macromolecule with a polymer at a pH near the isoelectric point of the macromolecule and incubating the mixture in the presence of an energy source for a predetermined length of time. The microparticles are composed of homogeneously distributed, intertwined macromolecule and polymer. Each microparticle allows aqueous fluids to enter and allows solubilized macromolecule and polymer to exit the microparticle and may be formulated to provide a sustained release of macromolecule and polymer from the interior of the microparticle when placed in an appropriate aqueous medium, such as under physiological conditions. Methods of production and methods of use for research, diagnostics and therapeutics are provided."

⚠️ Discrepancy flagged: the abstract text captured from the Google Patents page in the supplied authoritative text is truncated to a generic two-sentence placeholder ("Methods relating to the field of biochemistry…"). The complete abstract above comes from the Justia and Typeset mirrors of the same document. I'm treating the fuller version as the substantive abstract but noting the mirror inconsistency.

Plain-language overview

The patent covers an aqueous, organic-solvent-free way of turning proteins/peptides/nucleic acids/other macromolecules into small solid spheres, and the spheres themselves.

• Core process: mix the macromolecule with a soluble polymer (e.g., PVP + PEG, or dextran) in water, adjust pH to near the macromolecule's isoelectric point, then apply energy (typically heat, ~37–90 °C for minutes to hours) so the polymer dehydrates/excludes water from the macromolecule, causing it to collapse into a microparticle.
• Key structural twist: unlike PLGA microspheres, here the macromolecule is the majority component of the particle (≥40% and <100% by weight), with polymer ≤30%. The two are "intertwined"/homogeneously distributed in a water-soluble matrix.
• Release behavior: the particle is permeable; aqueous fluid enters and solubilized macromolecule/polymer diffuses out, giving sustained release that can be tuned by polymer type/concentration, temperature, pH, and incubation time — and can be made to avoid the "burst effect."
• Applications claimed in the specification: separations/affinity chromatography, diagnostics and immunoassays, targeted and sustained drug delivery (leuprolide, nafarelin, insulin, LHRH, doxorubicin), vaccines/adjuvants, gene delivery, and in vivo/histopathological imaging.

Independent claims — ⚠️ uncertainty

I do not have authoritative, verified claim text for US 6,268,053 specifically, and I will not reconstruct it. The full text supplied to me ends within the "Detailed Description" and does not include the claims section; my searches returned claim language only for the parent, US 6,090,925 (e.g., its claim 20 "A method of making microparticles comprising combining a macromolecule and a polymer in an aqueous solution at a pH near the isoelectric point…", claim 21 "A microparticle prepared by a method comprising…", and claim 43 "A method for delivering a therapeutic agent…"). Those are different claims in a different patent and should not be attributed to '053.

What I can say with reasonable confidence, grounded in the '053 specification and its classification profile (A61K 47/6929 nanoparticle/solid-microparticle classes, C07K 1/30 precipitation-as-complexes, G01N 33/54313 particulate immunoassay carriers), is that its independent claims are expected to fall into these categories — stated here as inference, not verified fact:

1. A composition-of-matter claim to the microparticle itself, characterized by the macromolecule-rich (≥40 wt%) intertwined macromolecule/polymer matrix and the pH-near-pI/energy-source formation route.
2. A method-of-making claim (combine macromolecule + soluble polymer at pH near pI → expose to energy source → recover microparticles).
3. One or more method-of-use claims for diagnostic/therapeutic/research applications (delivery of a therapeutic agent, isolating a target molecule, detecting a target biomolecule).
4. Possibly a kit claim.

Anyone relying on this for a freedom-to-operate or invalidity analysis must pull the actual granted claim set from USPTO PatentCenter / the printed patent, since the patent is expired (2013-03-09) but its disclosure is heavily cited in later microparticle patents.

Litigation / CAFC 2026 check

No CAFC docket or 2026 appellate activity involving US 6,268,053 was found. My searches of Federal Circuit 2026 docketing notices and 2026 patent litigation reporting returned unrelated matters — Contour IP Holding v. GoPro (No. 2026-2012), Teva v. Lilly (No. 2024-1094), STX v. StringKing, Nearby Systems v. Exxon Mobil, and ParkerVision updates — none of which assert the '053 patent. Patent-term math is consistent with this: the patent's anticipated expiration was 2013-03-09 (the 20-year term ran from the 1993-03-09 priority chain; the file history additionally shows a terminal disclaimer and an express abandonment-after-allowance followed by an RCE in late 2000), so the '053 patent has been expired for over a decade and is not a live asserted patent.

Separately, I did see "Epic Therapeutics" / "EPIC" appearing in D. Del. Hatch-Waxman litigation against Baxter, but that involves a different entity's patents — US 9,993,520, 11,135,265, and 11,207,372 (vasopressin formulations) — not the Epic Therapeutics microparticle portfolio and not the '053 patent. Do not conflate them.

Bottom line

US 6,268,053 is a Baxter/Epic Therapeutics-era patent (Woiszwillo et al.) on macromolecule-rich, polymer-dehydrated microparticles formed by near-pI, heat-driven volume exclusion in aqueous solution, with sustained-release and diagnostic/therapeutic uses. It issued 2001-07-31 from application 09/483,657, expired 2013-03-09, and shows no 2026 CAFC activity. The one item I could not verify authoritatively is the exact granted independent claim text, which is absent from the supplied document and should be confirmed against the official USPTO copy.

I'll search litigation databases and patent sources for US patent 6268053.

Let me dig deeper with more targeted searches.

Let me check specific litigation databases and the patent's family for related suits.

Litigation Search: U.S. Patent No. 6,268,053

Bottom line

I found no evidence of any litigation (district court, ITC, or PTAB/reexamination) specifically involving U.S. Patent No. 6,268,053. Based on the sources searched, no case appears to have asserted this patent.

About the patent (context for the search)

• Number: 6,268,053 B1 — "Macromolecular microparticles and methods of production and use"
• Inventors: Woiszwillo, Brown, Scott, Di, Sudhalter, Blizzard, Riske
• Original assignee: Epic Therapeutics, Inc. (Norwood, MA); later assigned to Baxter International Inc. / Baxter Healthcare SA (recorded 2003-06-10)
• Filing date: Jan. 14, 2000 (continuation of Ser. No. 08/699,586, now U.S. Pat. No. 6,090,925, which is a CIP of Ser. No. 08/206,456, now U.S. Pat. No. 5,578,709, a CIP of Ser. No. 08/028,237 filed Mar. 9, 1993)
• Grant date: July 31, 2001
• Legal status: Expired – Lifetime (anticipated expiration March 9, 2013)
• Field: Protein/macromolecule microparticles formed by mixing a macromolecule with a soluble polymer near the macromolecule's isoelectric point in the presence of an energy source; sustained-release drug delivery, diagnostics, separations

What the searches returned

• No complaint, docket, or judgment was located naming 6,268,053 as a patent-in-suit.
• The patent appears in the record only as prior art / a cited reference in other patents (e.g., EP 2774935 A1, JP 2012500118 A, EP 2429493 B1, RU 2457854 C2) — these are citation relationships, not litigation.
• Its family members/continuations (e.g., U.S. Pat. Nos. 6,090,925, 5,578,709, 6,458,387, and the EP equivalents EP 0688429, EP 1060741) likewise did not surface as asserted patents in the results.

Important caveat — do not conflate similar numbers

Several search hits involve Baxter and a patent referred to as the "'805 patent," but those are different patents, and I am flagging them so they are not mistakenly attributed to 6,268,053:

Note that a numeral string as innocuous as "805" attaches to many unrelated patents; none of the above is U.S. 6,268,053.

Confidence and limitations

• Confidence that no litigation is known: high, but not absolute. I could not exhaustively query every paywalled docket system. Unified Patents' litigation portal, Justia's patent page, CourtListener/Google Scholar case text, PTAB records, and general web sources returned no case asserting 6,268,053.
• Basis for the likely absence of suits: the patent expired in March 2013 (20-year term from the 1993 priority chain), which is well before the current date and reduces the likelihood of any active enforcement. Its cited role in the literature is as a foundational microsphere reference, not as an asserted patent.
• I did not fabricate any case, party, jurisdiction, or case number. Where I could not find a fact, I have said so.

Recommended next steps to confirm

Because you asked for litigation-grade certainty, I would verify against these primary sources directly (I could not fully query the paywalled ones):

1. PACER / CourtListener RECAP — full-text docket search for "6,268,053" and "6268053."
2. Unified Patents Portal (portal.unifiedpatents.com/litigation) — patent-level litigation tab for 6,268,053.
3. Lexis CourtLink / Westlaw KeyCite — patent history report (the same method the USPTO's CRU uses for its "Litigation Search Report").
4. USPTO Patent Center / Global Dossier — reassignment and any reexam/reexam certificate history (the 2003 assignment to Baxter is confirmed; no reexam was surfaced).

If you'd like, I can run targeted queries against any specific one of these once search access is available, or check the family members (6,090,925; 5,578,709; 6,458,387) for litigation, since a party enforcing the platform would more likely assert those.

Disclaimer: This is an informational search summary, not legal advice or a legal conclusion on the patent's status, ownership, or any party's rights.

I'll verify the structured data with web searches before drafting.

Let me run more targeted searches to confirm the absence of PTAB activity.

PTAB / AIA Trial Proceedings — US Patent 6,268,053 ("Macromolecular microparticles and methods of production and use")

Proceedings overview

There are zero AIA trial proceedings on file for US 6,268,053. The structured "PTAB proceedings on file" block — sourced from the USPTO Open Data Portal — returns no IPR, PGR, or CBM, and my independent web searches (Google Patents, Unified Patents' patent portal, RPX/PTAB document mirrors, Docket Alarm, and general PTAB-decision search) surfaced no petition, institution decision, final written decision, or appeal naming this patent. There is therefore no active/claims-invalidated/claims-sustained/settled/institution-denied breakdown to report — every bucket is empty.

Bottom-line defensive posture: the patent was never tested at the PTAB, so a defendant gets no free invalidating FWD to point at — but that is largely academic, because US 6,268,053's legal status is "Expired – Lifetime" with an anticipated expiration of 2013-03-09 (per Google Patents, https://patents.google.com/patent/US6268053/en). An expired patent cannot support prospective injunctive relief and its infringement exposure is limited to the § 286 six-year damages lookback, which for this patent ran out in 2019. The absence of PTAB activity is not evidence of a hardened patent here — it is consistent with a patent that simply aged out of commercial assertion before the AIA trial bar became the default first move.

No proceedings to itemize — what I verified instead

Because there is no proceeding number to put in the ### {PROCEEDING_NUMBER} template, I will not manufacture one. What follows is the verification record and the adjacent-risk analysis.

Verification record (searched 2026-09-27)

Distractors I affirmatively ruled out (do not confuse these with a proceeding on the '053 patent — the numbers are similar but the patents are different):

• IPR2020-00992, SK Innovation Co., Ltd. v. LG Chem, Ltd. — challenges US 8,012,626, not '053. (CourtListener/Docket Alarm also indexes this case as "IPR_Petition_626", which is a search-engine trap.)
• IPR2017-01587 — concerns US 9,149,626 (catheter/needle-safety art), unrelated field.
• IPR2017-01100, Actavis LLC v. Abraxis Bioscience LLC — albumin-particle art that cites the '053 family as background (e.g., WO 94/18954, US 5,525,519), but the challenged patent is an Abraxis one, not '053. Do not cite this as an '053 FWD.

Why the AIA-trial toolbox was narrow for this patent anyway

Even had a challenger wanted to file, the available vehicles were limited by the patent's pedigree:

• PGR: unavailable. PGR applies only to patents with at least one claim having an effective filing date on or after 2013-03-16. US 6,268,053 claims priority to 1993-03-09 (application 08/028,237 → 08/206,456 → 08/699,586 → this continuation 09/483,657, filed 2000-01-14). It is squarely a pre-AIA patent. (See the priority chain recited at the top of the specification.)
• CBM: unavailable in substance. CBM review required a "covered business method" patent — one claiming a technique used in the practice, administration, or management of a financial product or service. The '053 claims are directed to protein/polymer microparticle formation for separations, diagnostics, and drug delivery (see the summary of the invention). It is not a financial-services patent, so § 18 of the AIA would not have applied.
• IPR: the only realistic route. An IPR would have had to be filed within one year of service of an infringement complaint (§ 315(b)) and would have been limited to § 102/§ 103 grounds on patents and printed publications. No such petition was filed.

Strategic summary

Claim-level posture. The task cannot be answered at claim granularity because no adjudicative body has ever construed, canceled, or confirmed any claim of US 6,268,053 in an AIA trial. Correspondingly, no claim is "canceled," no claim is "sustained by the PTAB," and there is no FWD from which to quote a disposition. I will not assign a claim number to any status — the claim set is not even reproduced in the authoritative patent text supplied in this prompt, and inventing one would be fabrication. Practically speaking, the whole claim set is untested at the PTAB, and the patent is expired as of 2013-03-09 (Google Patents legal status: "Expired – Lifetime").

Estoppel landscape. Because no IPR/PGR/CBM was ever instituted, § 315(e)(2) estoppel does not exist for any party with respect to this patent. There is no petitioner (and therefore no privy or real party in interest) who is precluded from raising any § 102/§ 103 ground — the entire body of prior art remains procedurally available to a would-be challenger in a district court or ITC action. Conversely, there is no PTAB record to help a defendant either: no institution decision to cite for a § 325(d) argument, no FWD to quote, and no claim-construction ruling to borrow at Markman. What a challenger has instead is a fully open art canvas — and, because the patent expired in 2013, only a time-barred damages theory worth litigating.

Pattern signals. There is nothing to read as a pattern on this patent: no repeat petitioner, no serial IPR filings, no PTAB-side Patent Owner appeals, and no defensive aggregator (no Unified Patents, RPX, or similar) in the chain. The only "chain" evident from the file is corporate: original assignee Epic Therapeutics, Inc. (of the PROMAXX® protein-matrix technology), assignment to Baxter International Inc. / Baxter Healthcare SA recorded 2003-06-10, matching the assignee-of-record shown on Google Patents and Unified Patents' portal. The '053 patent is heavily cited in later pharmaceutical-particle patents (e.g., the 2005–2010 Baxter/Eastman PROMAXX family filings that list U.S. Pat. Nos. 5,525,519; 5,554,730; 5,578,709; 5,981,719; 6,090,925; 6,268,053; and 6,458,387 together), which is a citation-network signal, not a litigation or IPR signal.

Honest limits. I could not access the USPTO PTAB E2E docket directly in this session (no indexed case to open), and I cannot rule out a petition that was filed but never docketed/indexed, or a district-court validity challenge that never went to the Board. My conclusion is based on the canonical ODP block plus multiple public indexes agreeing on zero.

Recommended next steps

If you are a defendant and the demand letter or complaint cites US 6,268,053:

1. Lead with the expiration date, not the PTAB. Check the face of the patent and PAIR for the actual expiration/terminal-disclaimer math, but Google Patents states an anticipated expiration of 2013-03-09, with legal status "Expired – Lifetime" (https://patents.google.com/patent/US6268053/en). Any damages claim is confined to § 286's six-year lookback; on these dates that reaches back at most to 2020 — i.e., after expiration. Ask opposing counsel to identify the accused acts and their dates in writing.
2. There is no FWD to cite. Do not represent to a court that any claim "was canceled by the PTAB" — it was not, and there is no opinion at PTAB E2E (https://ptacts.uspto.gov) or on CourtListener (https://www.courtlistener.com) to link. Your validity defense is a clean slate: whatever § 102/§ 103 art you have is free of § 315(e)(2) estoppel, because no petitioner ever appeared.
3. Because the patent is pre-AIA, your invalidity theory must respect pre-AIA § 102/§ 103 law, and you cannot rely on AIA-conforming priority analysis to knock out the 1993-03-09 priority date. If, on the other hand, you want the earlier priority date to attach (e.g., to reach pre-1993 art), note the family's priority is 1993-03-09 through the '237 application — the specification expressly recites the chain.
4. Check the family too. The '053 is one node in a dense family (U.S. Pat. Nos. 5,525,519; 5,554,730; 5,578,709; 5,981,719; 6,090,925; 6,458,387, among others). A demand letter may be asserting a continuation or sibling, not '053. Confirm the exact patent number before relying on the "no PTAB activity" finding, since my search was scoped to 6,268,053 specifically and I did not verify trial history on every family member.
5. If any active proceeding does exist that I could not find: the statutory clock is one year from institution to FWD (§ 316(a)(11)), institution is decided within six months of the petition's filing (§ 314(b)), and joinder/termination requests are separately docketed. Send me the proceeding number and I will pull the institution decision, panel, and claim-level disposition.

Plainest version: there is no PTAB proceeding on this patent to brief. The patent's real vulnerability today is not a canceled claim — it is expiration on 2013-03-09, which for practical purposes ends the fight.

I'll research the assignment record and surrounding corporate history before reconstructing the chain.

Let me look for the specific reel/frame data and any later transfers (e.g., Baxalta/Shire spin-offs).

Assignment & Ownership Analysis — US 6,268,053 B1

Data-access caveats (read first). I was able to retrieve the patent document itself (Google Patents, https://patents.google.com/patent/US6268053/en) and confirm the two ownership events it lists, but the Assignment Center / assignment.uspto.gov records were not retrievable in this session (the search endpoint returned no records on direct query, and follow-up queries were rate-limited). Consequently:

• Reel/frame numbers are NOT reported below — I will not guess them. Google Patents' legal-events mirror does not display reel/frame.
• Correspondents of record are NOT reported — also not exposed by the mirror, and fabricating an attorney/firm would be a false finding.
• Everything below that is stated is grounded in the patent front matter, Google Patents legal events, and press/business sources cited inline. Treat the reel/frame and correspondent columns as open items to pull manually at https://assignment.uspto.gov/patent/index.html (search by patent number) and https://assignmentcenter.uspto.gov/.

Inventors

Seven named inventors on US 6,268,053:

Pattern note (unusual, but benign): this application is a continuation chain — filed 2000-01-14 as Ser. No. 09/483,657, continuing Ser. No. 08/699,586 (filed 1996-08-19, now US 6,090,925), which was a CIP of Ser. No. 08/206,456 (filed 1994-03-04, US 5,578,709), itself a CIP of Ser. No. 08/028,237 (filed 1993-03-09, abandoned). The inventor→company assignment was therefore recorded in April 2000, ~7 years after the 1993 priority date and ~3 months after the 2000 continuation was filed — a confirmatory/clean-up assignment typical of continuation practice. The 1993–1996 priority filings were likely covered by assignments recorded against the earlier-issued parents (US 5,578,709, US 6,090,925); I could not verify those parent records here.

No departure pattern observed. There is no evidence of all inventors leaving the original assignee within 12 months of filing. To the contrary, the inventive team was still inside Epic Therapeutics when Baxter acquired the company in 2002 (Brown was still publicly identified as Epic's CTO at acquisition time).

Original assignee

Epic Therapeutics, Inc. — named original assignee on the issued patent (Google Patents front matter; current assignee listed as Baxter Healthcare SA / Baxter International Inc.).

• Primary business: privately held drug-delivery company, HQ 220 Norwood Park South, Norwood, MA; ~38 employees at acquisition. Developed the PROMAXX / ProMaxx water-based protein-microsphere technology (the commercial embodiment of the claims in this family), lead product LeuProMaxx (leuprolide, 28-day and 84-day formulations) plus PROMAXX inhaled insulin. (Sources: Baxter/Epic acquisition press release, 2002-11-11; Pharmaceutical Technology "In the Field" profile; Chicago Tribune 2002-11-12.)
• Product shipped? Partially — the platform was scaled to cGMP and licensed/used for clinical programs; whether LeuProMaxx ever obtained FDA approval is not verified here. Baxter later (2007) presented Phase I inhaled-insulin results using PROMAXX.
• Current status: Acquired and dissolved as a separate entity. Baxter Healthcare Corp. signed a definitive agreement 2002-11-11 to acquire Epic for $50–100M, closing Q4 2002 (Chicago Tribune; Memphis Business Journal; PRNewswire 2002-11-11). Epic operated as a Baxter subsidiary. Note: Tracxn and other databases indicate Epic was formerly Middlesex Sciences — a possible change-of-name event that I could not confirm as a recorded assignment against this patent.

Assignment timeline

Two ownership events are visible on the patent's legal-events record. Reel/frame and correspondent were not retrievable (see caveat above); execution dates are not exposed by the mirror.

• Execution date not exposed / recorded 2000-04-25 — Reel/frame not retrieved

  • Conveyance: Assignment (inventor → company)
  • Assignor: Woiszwillo, James E.; Brown, Larry R.; Scott, Terrence L.; Di, Jie; Sudhalter, Judith; Blizzard, Charles D.; Riske, Frank J. (all seven named inventors)
  • Assignee: Epic Therapeutics, Inc.
  • Correspondent: not retrieved
  • Context: Initial inventor-to-company assignment; recorded ~3 months after the 2000-01-14 continuation filing — a confirmatory chain-of-title filing, not a transfer to a third party.

• Execution date not exposed / recorded 2003-06-10 — Reel/frame not retrieved

  • Conveyance: Assignment (M&A / corporate acquisition)
  • Assignor: Epic Therapeutics, Inc.
  • Assignee: Baxter International Inc. and Baxter Healthcare SA (a corporation of Switzerland) — joint assignees, the standard Baxter U.S. parent + Swiss holding pairing
  • Correspondent: not retrieved
  • Context: Acquisition — Baxter's purchase of Epic Therapeutics (~$50–100M, announced 2002-11-11, closed Q4 2002; recorded at USPTO 2003-06-10).

No later assignments are visible on the sources I reached. Google Patents records the patent as "Expired – Lifetime," anticipated expiration 2013-03-09. Because the term ended in 2013, the Baxter biopharma spin-off chain (Baxalta 2015 → Shire 2016 → Takeda 2019) is not expected to touch this patent, and I found no evidence that it did. (Unverified — I could not confirm by direct PEDS/ODP query.)

Timeline diagram

timeline
    title Ownership of US 6268053
    1993 : Priority application filed
    2000 : Continuation application filed
         : Inventors assign to Epic Therapeutics
    2001 : Patent US6268053 issues
    2002 : Baxter signs deal to acquire Epic
    2003 : Epic assets assigned to Baxter
    2013 : Patent term expires

NPE / troll-pattern signals

1. Shell-entity transfer — not present. The only post-issuance transfer (recorded 2003-06-10) moved the patent from an operating drug-delivery company to Baxter International Inc. / Baxter Healthcare SA, a NYSE-listed operating manufacturer. No "IP / Holdings / Ventures / Licensing" suffix appears anywhere in the chain. No registered-agent-service address is evidenced.
2. Known asserter in the chain — not present. Neither Epic Therapeutics nor Baxter International/Baxter Healthcare SA appears on the enumerated NPE list (Acacia, Marathon, IV, IPNav, Wi-LAN, Conversant, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, Document Generation Corp, Spangenberg entities). No RPX/Unified high-frequency-plaintiff match surfaced in my searches; Baxter is not an NPE.
3. Repeat correspondent across the chain — unclear / not verifiable. The correspondent of record is not exposed by the sources I could reach, and both events were unretrievable from the Assignment Center. No correspondent finding can be made. This is the single most important item to pull manually; if the 2000 and 2003 recordings share a correspondent it is almost certainly ordinary Baxter/Epic outside-counsel continuity, not an NPE broker.
4. Cascading transfers — not present. Exactly two recorded events span 1993–2003; there is no chain of LLCs, and no cluster of transfers within <24 months.
5. Pre-litigation transfer — not present. I found no infringement litigation naming US 6,268,053 on the sources searched, and no transfer within 6 months of any suit. (Caveat: a full Docket Navigator / PACER / RPX run was outside this session's reach.)
6. Bankruptcy fire-sale — not present. Epic Therapeutics was acquired at a negotiated price ($50–100M), not sold in bankruptcy; Baxter is solvent and operating.
7. Privateering — not present. Baxter acquired the entire company (38 employees, the Norwood R&D site, and the PROMAXX platform) for in-house drug-delivery service offerings — the opposite of transferring a patent to a proxy asserter while the operating company stays out of court. No evidence of Baxter-funded assertion against competitors.
8. Defensive aggregator — not present. The chain terminates at Baxter, not at RPX, AST, LOT Network, Unified Patents, or OIN. Inverse signal (neutralization) does not apply.

Verdict

Insufficient data — no NPE pattern detected.

Justification: only two ownership events are on record — the inventor→Epic Therapeutics assignment and the recorded 2003-06-10 assignment of Epic's rights to Baxter International Inc. and Baxter Healthcare SA — and the chain then runs unbroken to the patent's 2013-03-09 expiration. The last assignee is a large, solvent, product-shipping operating company that bought Epic in a negotiated $50–100M transaction, and none of the eight NPE signals is affirmatively present. I stop short of a clean "operating-company / non-asserting" call only because the enumerated verdict buckets have no slot for "operating company, no assertion evidence," and because reel/frame and correspondent could not be verified in this session — pull those two fields manually before treating this as final.

Verify at: https://assignment.uspto.gov/patent/index.html (search "6268053") and https://assignmentcenter.uspto.gov/ — confirm (a) reel/frame for each of the two entries, (b) the correspondent of record on each, and (c) whether any post-2013 record exists (not expected, since the term expired).