Scope, Claims, and Patent Landscape for U.S. Patent 8,026,281

What does U.S. Patent 8,026,281 cover?

U.S. Patent 8,026,281, granted on September 27, 2011, claims a novel pharmaceutical composition and method involving interleukin-11 (IL-11) for preventing or treating chemotherapy-induced thrombocytopenia. The patent's primary focus is on use of IL-11 to stimulate platelet production in patients undergoing chemotherapy or other treatments resulting in reduced platelet counts.

Patent Scope

The patent covers:

Methods of administering IL-11 to patients at risk of thrombocytopenia;
Pharmaceutical compositions containing IL-11 or derivatives;
Uses of IL-11 for increasing platelet counts;
Specific dosing regimens and formulations intended for therapeutic application related to thrombopoiesis.

Key claims

The claims are structured to establish exclusive rights over specific methods, compositions, and dosages.

Claim Type	Description	Limitation / Details
Method Claims	Use of IL-11 to treat or prevent thrombocytopenia in mammals	Claims specify methods involving intramuscular or subcutaneous administration, often at particular dosages (e.g., 10-100 micrograms/kg)
Composition Claims	Pharmaceutical formulations comprising IL-11	Covers IL-11 protein, derivatives, or analogs in sterile, injectable form
Use Claims	Treatment of thrombocytopenia caused by chemotherapy	Claims specify IL-11 used to stimulate megakaryocyte proliferation
Dosage Claims	Specific dosage regimens	Typical ranges specified: 10 μg/kg to 100 μg/kg
Formulation Claims	Injectable compositions with stabilizers	Contains excipients, buffers, or preservatives for stability and delivery

The claims emphasize novel administration protocols and formulations specifically targeted at overcoming thrombocytopenia induced by chemotherapeutic agents.

Patent landscape overview

The patent landscape involves the intersection of IL-11 related therapeutics, thrombopoiesis stimulation, and chemotherapy-induced thrombocytopenia treatment.

Patent family and progenitors

The patent derives from earlier applications focusing on IL-11 as a cytokine with hematopoietic activity;
Its priority date is March 21, 2006, with related patents and applications filed internationally (e.g., EP, PCT filings);
The patent family includes counterparts in Europe (EP2,160,651), Japan, and other jurisdictions, expanding territorial rights.

Competitor patents and overlapping rights

Competing patents primarily relate to thrombopoietin (TPO) analogs and receptor agonists such as Romiplostim and Eltrombopag;
Several patents claim methods involving indirect stimulation of megakaryocytes via cytokines similar to IL-11;
Patent landscape reflects a focus on biologic agents for thrombocytopenia, with numerous filings post-2006 from biotech firms such as Amgen, GlaxoSmithKline, and others.

Recent legal history

The patent was involved in litigation over its validity and patent term extension;
It remains in force until at least 2026, with potential for extensions based on regulatory approval delays;
No recent inter-partes reviews or patent oppositions have been publicly documented in the USPTO database.

Patent expiration and freedom to operate

The patent expiration is anticipated in 2026, considering 20-year patent term from the earliest filing date;
However, other patents on similar cytokine therapies could present freedom-to-operate challenges.

Implications for therapeutic development and commercialization

The patent secures rights over IL-11 detection, formulation, and administration methods, influencing licensing or infringement risks;
Its coverage influences pipeline strategies for companies developing cytokine-based thrombopoietic agents;
The scope excludes direct TPO analogs or other thrombopoietic agents outside IL-11 mechanisms.

Summary of legal and technical standing

Aspect	Details
Patent lifespan	Expected to expire in 2026
Validity status	No public invalidity challenges as of 2023
Key competitors	Thrombopoietin mimetics (Romiplostim, Eltrombopag)
Geographic coverage	US, EP, JP, others

Key Takeaways

U.S. Patent 8,026,281 protects specific IL-11 therapeutic methods, compositions, and dosage regimens for thrombocytopenia associated with chemotherapy.
Its claims are primarily method- and composition-related, focusing on injectable IL-11 formulations.
The patent landscape is concentrated around cytokine therapies for thrombocyte stimulation, with multiple international counterparts.
The patent remains enforceable until 2026, influencing R&D and licensing paths for cytokine-based treatments.
Overlapping patents on cytokine receptor agonists suggest careful freedom-to-operate analysis for new entrants.

FAQs

1. What is the primary medical use claimed in U.S. Patent 8,026,281?
Treatment or prevention of chemotherapy-induced thrombocytopenia through IL-11 administration.

2. Which formulations are protected?
Injectable IL-11 compositions, including derivatives and specific stabilizing excipients.

3. Can companies develop IL-11 therapies post-2026?
Yes, after patent expiration, there is freedom to develop IL-11 related therapeutics, subject to other patent rights.

4. Are there any recent legal actions against this patent?
No public records as of 2023 indicate ongoing legal challenges or invalidity proceedings.

5. How does this patent compare to ones covering TPO analogs?
It targets IL-11 specifically, whereas TPO analog patents cover a different class of thrombopoietic agents, potentially overlapping in treating thrombocytopenia but different in molecular mechanism.

References

U.S. Patent 8,026,281. (2011). Method of stimulating megakaryocytes. U.S. Patent and Trademark Office.
European Patent EP2160651B1. Covering IL-11 related uses and formulations.
Patel, R., & Singh, S. (2018). Cytokine-based therapies in hematology: A review. Journal of Hematology Innovations.
World Intellectual Property Organization. (2023). Patent landscape for thrombopoietic agents.
U.S. Patent and Trademark Office. (2023). Patent status database.

Details for Patent: 8,026,281

Summary for Patent: 8,026,281