Invalidity dossier
US 5741495
Glucan drug delivery system and adjuvant
Current assignee: Alpha Beta Technology Inc
Added 9/21/2026, 1:02:05 PM
Active provider: DeepSeek · deepseek-flash
Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
Patent Overview — US 5,741,495 A
Title: Glucan drug delivery system and adjuvant
Assignee/Applicant of record: Alpha Beta Technology Inc (original assignee); current assignee listed as Alpha Beta Technology Inc / Biopolymer Engineering Inc. Google notes assignee listings "may be inaccurate."
Key dates: Priority date 1989-06-15; filing date 1997-02-27 (application US08/810,947); granted/publication date 1998-04-21; anticipated expiration 2009-06-15. Legal status: Expired – Fee Related.
Inventors: Spiros Jamas, Gary R. Ostroff, D. Davidson Easson, Jr.
Purpose: The patent describes a pharmaceutical composition that functions simultaneously as a drug delivery vehicle and as an adjuvant. The composition comprises whole glucan particles (whole β-glucan particles — micron-sized hollow spheres with a rigid, semi-permeable glucan matrix that retain the in vivo three-dimensional morphology of yeast cell walls) plus a pharmacologically active substance such as a drug or antigen. The β-glucan acts as an adjuvant by non-specifically enhancing immune response, reportedly via interaction with β-glucan receptors on monocytes, inducing interleukin-1 and other cytokines.
Plain-language scope: A drug or antigen can be contained within (encapsulated/entrapped in the hollow cavity), uniformly dispersed in, or chemically linked to the whole glucan particles. Entrapped drug releases through the glucan matrix into the physiological environment. The vehicle is described as targeting drug or vaccine to macrophages, activating those cells, and extending in vivo half-life by protecting against degradation and rapid clearance. Release rate can be controlled, e.g., by crosslinking or by modifying β-glucan branching/water-holding capacity. Figures 1–7 show protein release rates and antibody titers for BSA and P55 formulations (mixed vs. crosslinked).
Source: https://patents.google.com/patent/US5741495/en
What the excerpt does not establish: No claim language, full specification, or examples are included here, so the exact scope of the claims, dosage forms, quantitative release data, efficacy results, and the complete list of drugs/antigens are not shown. The excerpt also does not establish current ownership, enforceability, or validity.
Generated 10/1/2026, 10:00:59 PM
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Litigation summary
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Proceedings on file (0)
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No PTAB proceedings on file. This patent has not been challenged via IPR, PGR, or CBM. The absence is itself a signal — well-asserted patents eventually attract IPRs. The LLM analysis below may surface filings the ODP feed hasn’t indexed yet.
PTAB challenges
AIA trial proceedings at the USPTO Patent Trial and Appeal Board — IPR, PGR, and CBM. Petitioners, judge panels, claim-level invalidation outcomes from Final Written Decisions, and Federal Circuit appeals. The single most important defensive datapoint after litigation history.
Assignment history
Inventors, original assignee, and the chain of ownership recorded with the USPTO — including the correspondent attorney who recorded each assignment, since shell-LLC chains often share one repeat-player attorney even when the entity names look unrelated. Surfaces NPE / patent-troll patterns: shell-entity transfers, known asserters in the chain, repeat correspondent fingerprints, pre-litigation assignments, and bankruptcy fire-sales.
Prior art
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Obviousness
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Extensions
Patent term adjustments, term extensions, continuations, divisionals, family members, and expiration dates.
Derivative works
Defensive disclosure: derivative variations of each claim designed to render future incremental improvements obvious or non-novel.