Patent: 6,066,317

Summary for Patent: 6,066,317

Title:	Method of using IL-11 for treating deficiencies in hematopoietic progenitor or stem cells
Abstract:	A novel mammalian cytokine, IL-11, and processes for producing it are disclosed. IL-11 may be used in pharmaceutical preparations for stimulating and/or enhancing cells involved in the immune response and cells involved in the proper functioning of the hematopoietic system.
Inventor(s):	Yang; Yu-Chung (Indianapolis, IN), Bennett; Frances K. (Melrose, MA), Paul; Stephan R. (Wyncote, PA)
Assignee:	Genetics Institute, Inc. (Cambridge, MA)
Application Number:	09/122,525
Patent Claims:	see list of patent claims

United States Patent 6,066,317 Claims Analysis and US Patent Landscape for IL-11 Hematopoietic Progenitor/Stem Cell Treatment

Executive summary

US Patent 6,066,317 covers a method of treating deficiencies in hematopoietic progenitor or stem cells by administering an IL-11 aqueous pharmaceutical composition with a pharmaceutically acceptable carrier, with a dependent claim specifying an IL-11 amino acid sequence corresponding to SEQ ID NO. 2. The claim set is narrow in therapeutic scope and formulation modality (aqueous solution), but broad in that it does not require a specific indication subtype, dosing regimen, route, or patient population beyond “deficiencies” in hematopoietic progenitors/stem cells. The key enforceability and freedom-to-operate (FTO) issues hinge on (i) what “deficiencies” covers, (ii) whether IL-11 is structurally limited to the SEQ ID NO. 2 sequence, and (iii) whether later IL-11 products and biosimilar-style or formulation variants still practice the claim.

Because this request is limited to claim 1-2 text and does not provide the rest of the patent (specification details, priority dates, prosecution history, or prosecution claim scope such as whether IL-11 is human IL-11 or a particular analog), a complete, accurate cross-patent landscape mapping cannot be produced.

What does US Patent 6,066,317 claim for IL-11 aqueous solution treatment of hematopoietic stem/progenitor deficiencies?

Claim 1
A method for treating deficiencies in hematopoietic progenitor or stem cells by administering:

• a pharmaceutical composition comprising
• an aqueous solution of IL-11
• with a pharmaceutically acceptable carrier.

Claim 2
Claim 1 method where:

• IL-11 comprises an amino acid sequence set forth in SEQ ID NO. 2.

Claim scope: what is actually covered

• Therapeutic target: “deficiencies in hematopoietic progenitor or stem cells.” This targets hematopoietic stem cell biology broadly, but the phrase “deficiencies” is not limited to one clinical diagnosis in the claim text provided.
• Mechanism proxy: The claim is drafted as a treatment method keyed to IL-11 administration, not to a particular dosing schedule or route.
• Drug substance constraint: Claim 1 does not specify an IL-11 identity beyond “IL-11” in aqueous form. Claim 2 narrows to IL-11 having a specific amino acid sequence (SEQ ID NO. 2).
• Formulation modality: Claim 1 is expressly limited to an aqueous solution. This excludes certain non-aqueous systems, long-acting depots, or delivery platforms if they are not “aqueous solution” as construed.

What is not required by the claims as provided

• No requirement for:
  • specific indication (eg, post-transplant marrow suppression, chemotherapy-induced neutropenia, thrombocytopenia, anemia, or marrow aplasia),
  • specific route (IV, SC, intrathecal, etc.),
  • specific dose or frequency,
  • a comparator,
  • concomitant therapies,
  • patient demographics,
  • or a specific manufacturing/processing parameter.

Claim interpretation risk points

• “Deficiencies”: Could be construed narrowly (clinical deficiency states) or broadly (measurable functional impairment). Litigation typically turns on how the specification uses the term, which is not provided here.
• Aqueous solution: If a later product is described as a suspension, lyophilized powder reconstituted to a solution, or contains solvents that change the characterization, claim construction and infringement analysis will hinge on formulation facts and expert testimony.
• SEQ ID NO. 2: Claim 2’s validity and infringement depend on what sequence SEQ ID NO. 2 corresponds to (human IL-11 versus variant/analog). Without the sequence mapping from the specification, exact scope cannot be verified.

Is the IL-11 sequence limitation in claim 2 a meaningful narrowing feature or a technicality?

Claim 2 adds a structural requirement:

• IL-11 “comprises an amino acid sequence as set forth in SEQ ID NO. 2.”

Why the sequence limitation matters

• Design-around: Competitors could avoid claim 2 if they use IL-11 variants that differ from SEQ ID NO. 2. Whether “comprises” allows conservative substitutions or partial sequences depends on claim construction and the specification.
• Validity pressure: If SEQ ID NO. 2 is identical or obvious relative to known IL-11 at the priority date, claim 2 may be vulnerable on obviousness, even if claim 1 survives due to formulation modality.
• Infringement pressure: If later IL-11 products use the same sequence as SEQ ID NO. 2, claim 2 becomes a powerful enforcement hook.

Where claim 2 may still be circumvented

• If a competitor uses an IL-11 molecule that is not literally covered by SEQ ID NO. 2.
• If “aqueous solution” is avoided in practice (eg, different delivery or depot forms not “aqueous solutions”).
• If the competitor pursues a different therapeutic rationale that does not meet “deficiencies in hematopoietic progenitor or stem cells” as construed.

What other US patent claims in the landscape typically overlap with this IL-11 hematopoietic method claim?

Without performing a full bibliographic search in the USPTO/Orange Book and without access to additional patent numbers from the record, an accurate landscape cannot be enumerated. That said, the infringement and freedom-to-operate issues for IL-11-based hematopoietic methods in the US usually overlap across four IP layers:

1) IL-11 composition and sequence patents

• IL-11 amino acid sequence claims (human IL-11 or specific variants)
• IL-11 nucleic acids and expression systems
• IL-11 formulations and stabilizers (buffers, surfactants)
• PEGylated or fused IL-11 analogs (sequence and structural variants)

2) Method-of-use patents

• Use of IL-11 to treat specific hematopoietic dysfunctions
• Post-chemotherapy or post-radiation hematopoietic recovery
• Transplant conditioning-associated marrow suppression
• Mobilization or engraftment-related uses

3) Formulation and administration patents

• Aqueous formulation claims
• Reconstitution, concentration ranges, pH, and excipient selection
• Delivery system claims that may or may not remain “aqueous solutions”

4) Process and manufacturing patents

• Cell line engineering
• Purification methods
• Aggregation control and stability improvements

In practice, US litigation risk concentrates where a later product’s label, clinical use, and formulation facts align with the older claims’ structural and therapeutic limitations.

How could competitors design around the aqueous IL-11 method claim?

Based on claim language alone, the principal design-around levers are:

1) Avoid “aqueous solution”

• Use non-aqueous delivery systems, lyophilized formats that are characterized differently post-reconstitution, or depot formats not considered “aqueous solution.”
• Ensure labeling and administration protocols align with the non-queous or non-solution characterization.

2) Avoid “IL-11 comprising SEQ ID NO. 2”

• Use an IL-11 variant whose amino acid sequence does not match SEQ ID NO. 2.
• If claim 2 is the enforcement target, this is the cleanest route.

3) Avoid “deficiencies in hematopoietic progenitor or stem cells”

• Seek approvals for indications framed differently.
• If the label is broadened or uses symptom language rather than stem/progenitor deficiency language, infringement may turn on whether the claimed deficiency concept is met.

When does US Patent 6,066,317 lose exclusivity (patent expiration and term)?

Cannot be determined from the information provided. A patent term analysis requires filing date, priority date, patent term adjustments, and any terminal disclaimer data from the granted record.

What Orange Book status applies to IL-11 products potentially overlapping US 6,066,317?

Cannot be determined from the information provided. Orange Book status requires mapping the patent to specific approved drug products and listing relationships.

What Paragraph IV or litigation risks exist for IL-11 hematopoietic method claims like these?

Cannot be determined from the information provided. Litigation risk depends on:

• current or historical challenges to listed patents,
• whether the listed patents include 6,066,317 or co-listed patents,
• settlements and consent judgments, and
• whether generic and biosimilar applicants target the same claims.

Which companies are likely practicing or challenging this IL-11 hematopoietic method claim?

Cannot be determined from the information provided. Company-level attribution requires product-to-patent mapping, prosecution assignees, and litigation party identification.

How strong is the patent estate for IL-11 hematopoietic progenitor/stem cell treatment beyond claims 1-2?

Cannot be determined from the information provided. A strength assessment depends on:

• the full claim set (including scope breadth in other claims),
• dependent claim layering,
• whether claims cover antibodies, agonists, analogs, fusion proteins, or specific excipients,
• and the specification’s enablement and written description support.

Key takeaways

• US 6,066,317 claim 1 is a method-of-treatment claim covering IL-11 in an aqueous solution plus a pharmaceutically acceptable carrier for deficiencies in hematopoietic progenitor or stem cells; it is not limited to one disease or dosing regimen in the provided claim text.
• US 6,066,317 claim 2 narrows IL-11 to the amino acid sequence defined in SEQ ID NO. 2; this sequence limitation is the primary structural narrowing lever.
• The main design-around paths, based on claim language alone, are avoiding an aqueous solution characterization, avoiding IL-11 molecules matching SEQ ID NO. 2, and avoiding treatment of the claimed stem/progenitor deficiency concept as construed.
• Exclusivity timelines, Orange Book status, and competitive litigation exposure cannot be determined without a complete patent bibliographic record and product-to-patent mapping.

FAQs

1. What does “aqueous solution of IL-11” mean for infringement analysis if the IL-11 is supplied as a lyophilized powder?
2. Does “IL-11 comprises an amino acid sequence as set forth in SEQ ID NO. 2” cover conservative substitutions or only exact identity?
3. How do US courts construe “deficiencies in hematopoietic progenitor or stem cells” in method-of-use claims?
4. If a competitor uses IL-11 for a labeled indication that indirectly affects hematopoietic progenitors, does that satisfy the claim’s deficiency requirement?
5. Can route-of-administration differences (IV vs SC) avoid infringement where the claim does not recite a route?

References

1. United States Patent 6,066,317 (claims provided in prompt).

Details for Patent 6,066,317

Applicant	Tradename	Biologic Ingredient	Dosage Form	BLA	Approval Date	Patent No.	Expiredate
Wyeth Pharmaceuticals Inc.	NEUMEGA	oprelvekin	For Injection	103694	November 25, 1997	6,066,317	2018-07-24

International Patent Family for US Patent 6,066,317

Country	Patent Number	Estimated Expiration
World Intellectual Property Organization (WIPO)	9107495
United States of America	5854028
United States of America	5700664
United States of America	5371193
United States of America	5215895