Patent: 8,377,690

Summary for Patent: 8,377,690

Title:	Cells and methods for producing blocking antibodies to human RANKL
Abstract:	Described herein are cell lines and methods for preparing antibodies that bind RANKL, including cell lines that produce blocking antibodies to human RANKL.
Inventor(s):	Anderson; Dirk M (Port Townsend, WA)
Assignee:	Immunex Corporation (Thousand Oaks, CA)
Application Number:	12/802,801
Patent Claims:	see list of patent claims

United States Patent 8,377,690: Blocking Anti-RANKL Antibodies That Inhibit RANKL-RANK Binding

United States Patent 8,377,690 (issued Feb. 12, 2013) claims a cell and antibody production methods centered on a “blocking antibody” that binds human RANKL and inhibits RANKL binding to human RANK. The claims are narrow in their functional language (blocking binding between RANKL and RANK) and in their structural definitions (SEQ ID NO:13 and specified RANKL fragments). The practical enforceability turns on whether accused antibodies bind the specific RANKL epitope(s) embodied by SEQ ID NO:13 and its two enumerated fragments, and whether infringement is pleaded through antibody sequences/epitope mapping or only through functional blocking assays.

What does US 8,377,690 claim, in plain patent terms?

The asserted independent claim is effectively a composition-of-means claim (a producing cell) tied to an antibody specificity and a functional inhibition outcome.

Claim set (as provided)

Claim 1.
A cell that produces a blocking antibody where the blocking antibody:

• binds human RANKL polypeptide as set forth in SEQ ID NO:13, and
• inhibits binding of human RANKL to human RANK (SEQ ID NO:6).

Claim 2.
Same concept as claim 1, but the antibody binds a fragment of human RANKL as set forth in SEQ ID NO:13, inhibiting RANKL-RANK binding, where the fragment is selected from:

• (a) extracellular domain comprising amino acids 69-317 of SEQ ID NO:13; or
• (b) receptor binding domain comprising amino acids 162-317 of SEQ ID NO:13.

Claim 3.
Method of producing a blocking antibody by culturing the cell of claim 1 under conditions that permit antibody production.

Claim 4.
Method of producing a blocking antibody by culturing the cell of claim 2 under conditions that permit antibody production.

Structural and functional “hinges” that control infringement and validity

1. Identity of the RANKL antigen definition

   • The claims anchor to “human RANKL polypeptide as set forth in SEQ ID NO:13.”
   • This matters because RANKL (TNFSF11) has multiple forms and known sequence variants. If an accused antibody binds a different RANKL isoform or a nonmatching engineered construct, the SEQ ID tie can become a claim-limiting feature.

2. The epitope scope implied by SEQ ID NO:13

   • Claim 1 does not explicitly limit to a fragment; it limits to binding “as set forth in SEQ ID NO:13.”
   • Claim 2 narrows further to two specific fragments (69-317 and 162-317), mapping to extracellular and receptor-binding portions. This is likely designed to align with functional binding surfaces used in earlier RANKL biology and antibody characterizations.

3. Functional inhibition requirement

   • “Inhibits binding” of RANKL to RANK is a functional limitation.
   • In litigation, functional language can be satisfied by evidence of blocking activity even if exact epitope details are disputed, but it also raises enablement and definiteness pressure depending on how the patent defines or demonstrates the inhibition.

4. “Cell that produces” framing

   • The claims are production-cell claims, not antibody claims per se.
   • Infringement often requires proof of the producing organism/cell line and the antibody it produces, which is a higher bar for plaintiffs but also gives defendants leverage to focus on what antibodies are actually made and in what way.

Is this patent likely to be enforceable against known anti-RANKL products?

US 8,377,690 sits in the anti-RANKL competitive field dominated by denosumab (an anti-RANKL monoclonal antibody). Denosumab blocks RANKL-RANK interaction and is used for osteoporosis and bone metastases.

However, enforceability depends on whether the claimed antibody specificity is captured by:

• SEQ ID NO:13 binding, and/or
• the specific binding to fragments 69-317 or 162-317 of SEQ ID NO:13.

Landscape-critical distinction

• Denosumab binds human RANKL and blocks its interaction with RANK. It is functionally within the claims’ blocking concept.
• But the patent’s infringement pivot is whether denosumab’s binding specificity matches the sequence-defined RANKL substrate (SEQ ID NO:13) and whether it binds one of the enumerated RANKL fragments (claim 2) as defined.

From a patent strategy perspective, the core question becomes whether US 8,377,690 is broad enough to capture any antibody that blocks RANKL-RANK, or narrow enough to capture only a particular antibody class defined by binding to SEQ ID NO:13 and the stated fragments. Because claims 1 and 2 are not written as “an antibody comprising X” or “with Y CDR sequences,” enforceability usually concentrates on antigen-binding compatibility and epitope coverage.

What the claim structure suggests

• Claim 1 targets binding to full-length “RANKL as set forth in SEQ ID NO:13,” which likely refers to a specific RANKL sequence used in the specification. That can function like a narrow antigen definition.
• Claim 2 explicitly lists two receptor-relevant fragments: 69-317 (extracellular domain) and 162-317 (receptor binding domain). If a competitor antibody binds the receptor binding domain but not the extracellular domain as defined, it may still satisfy claim 2(b) depending on how “receptor binding domain comprising amino acids 162-317” is interpreted in terms of fragment binding.

Where does novelty likely come from, and where is it vulnerable?

This is a “blocking antibody to RANKL” patent. The field already includes:

• anti-RANKL binding antibodies, including those that block RANKL-RANK signaling, and
• earlier demonstrations that RANKL antagonism prevents osteoclastogenesis and bone resorption.

So the novelty has to be either:

• a particular antibody that binds a specific epitope on RANKL (reflected via SEQ ID NO definitions and blocking function), and/or
• a particular production cell system.

Vulnerability drivers for validity challenges

1. Obviousness over prior anti-RANKL antibodies

   • If prior art includes anti-RANKL antibodies that block RANKL-RANK binding, a challenger can frame the differences as routine selection or screening of known targets.
   • The patent’s reliance on SEQ IDs and enumerated fragments can be attacked as an optimization rather than a true non-obvious invention.

2. Functional limitation may be attacked as result-driven claiming

   • “Blocking antibody” + “inhibits binding” can be alleged as capturing any antibody that achieves blocking without sufficiently distinguishing structurally.
   • While functional claiming is not automatically invalid, it can become vulnerable if prior art teaches multiple ways to block RANKL-RANK and the patent does not show a distinct technical solution.

3. Cell-producing claims can inherit prior art antibody content

   • Even if the claim is to “a cell that produces,” a validity challenge can argue the same cell type or production method is known for antibody expression, and the novelty is only in the antibody specificity already known in prior art.

Strengthening factors suggested by claim architecture

• The inclusion of SEQ ID NO:13 and amino acid ranges (69-317, 162-317) is a narrowing device. It is designed to avoid pure functional capture of any blocking anti-RANKL molecule.
• The specific antigen substrate and defined inhibition relationship can support arguments that not all anti-RANKL antibodies meet the claimed binding definition.

How does the claim scope translate into freedom-to-operate risk?

Freedom-to-operate risk is driven by two layers: (1) whether a competitor antibody is captured by the antigen-binding/fragment limitations and (2) whether their manufacturing cells or expression systems map to the “cell that produces” limitation.

Claim 1 capture test (practical infringement lens)

A competitor’s antibody is more likely captured if it:

• binds a human RANKL sequence identical to the one in SEQ ID NO:13, and
• blocks the binding of human RANKL to human RANK (SEQ ID NO:6) in a way that mirrors the patent’s inhibition definition.

If the competitor antibody binds RANKL but does not block RANKL-RANK binding directly (e.g., allosteric effects that do not inhibit binding in the defined assay format), claim 1 becomes harder to satisfy.

Claim 2 capture test (narrower epitope framing)

For claim 2, the key is whether the competitor antibody binds a RANKL fragment defined as:

• extracellular domain 69-317 (SEQ ID NO:13), or
• receptor binding domain 162-317 (SEQ ID NO:13).

If the competitor antibody binds an epitope outside those fragments, it may evade claim 2 while still potentially falling under claim 1 depending on the broader “binds human RANKL as set forth in SEQ ID NO:13” language.

Manufacturing-cell limitation (how defendants often fight)

Even if the antibody is within scope, defendants can contest infringement by challenging:

• whether their accused cell line is the claimed “cell,” and
• whether the cell “produces” the specific blocking antibody that meets the SEQ/fragment binding constraints.

Because antibody production is industrialized, defendants typically have extensive documentation on their expression constructs and cell banks. Plaintiffs often rely on reverse engineering and product-to-process inferences; the “cell that produces” framing can be a litigation pressure point.

Does the “method of producing” claim add independent protection?

Claims 3 and 4 are culturing-method variants:

• claim 3 ties to the claim 1 cell, and
• claim 4 ties to the claim 2 cell.

These method claims generally track the cell claims and do not usually expand scope beyond what the cell claims cover, because they depend on producing the same antibody from the corresponding cell. They can still add leverage if the accused process is clearly documented (e.g., specific cell line usage and culture conditions) and the cell claim is otherwise harder to prove.

What is the patent landscape posture: crowded field, but narrow claims can still matter

Even without reproducing every competitor patent in the record, the strategic reality is that anti-RANKL monoclonals are an intensely patented domain. The enforceable value of US 8,377,690 therefore typically comes from:

• whether it is positioned as a narrower epitope/SEQ-ID-defined antibody concept rather than a broad “any RANKL blocker” concept, and
• whether its priority and prosecution record let it withstand obviousness attacks in a crowded prior art set.

From a business perspective, this patent is likely most relevant for:

• next-generation anti-RANKL antibodies that are engineered with known RANKL epitope binding modes,
• companies selecting between RANKL blocking versus alternative mechanisms, and
• investors reviewing freedom-to-operate when antibody sequences or epitope mapping indicate potential overlap with SEQ ID NO:13-defined binding.

Key claim and landscape implications for decision-makers

1) Antigen/fragment definitions are the core gate

If a program’s antibody binding data shows it targets the RANKL receptor binding domain aligned with the patent’s 162-317 region (claim 2(b)), the risk increases materially. If it binds elsewhere, claim 2 may be harder to satisfy, though claim 1 can still capture if SEQ ID NO:13 full-length binding is present.

2) “Blocking” is not optional

A competitor antibody must inhibit RANKL binding to RANK. Antibodies that bind RANKL but do not block the ligand-receptor interaction in the relevant manner may avoid the functional limitation.

3) Cell claims shift the evidentiary fight toward manufacturing proof

Even when an antibody is well characterized, proving infringement of “cells that produce” depends on mapping the accused production system to the claimed producing cell concept. This can narrow practical enforcement unless product-to-process evidence is strong.

4) The crowded RANKL field raises validity pressure, but narrow SEQ/fragment elements can preserve enforceability

The claims are likely not broad enough to be read as any blocking anti-RANKL antibody in the abstract. That limitation can reduce obviousness exposure compared with purely functional antibody claims.

Key Takeaways

• US 8,377,690 claims anti-RANKL blocking antibodies defined by binding to a specific SEQ ID NO:13 RANKL polypeptide and inhibition of RANKL-RANK binding.
• Claim 2 narrows scope through two enumerated RANKL fragments within SEQ ID NO:13: 69-317 (extracellular domain) and 162-317 (receptor binding domain).
• Enforceability depends on epitope/sequence alignment with SEQ ID NO:13 and whether the antibody blocks RANKL binding to RANK in the manner required by the claims.
• The “cell that produces” format makes infringement proof and defense heavily dependent on manufacturing evidence, not only on binding assays.
• In a crowded anti-RANKL landscape, the practical risk focuses on antibodies engineered for receptor-binding-domain blockade and on production pathways tied to the claimed producing cells.

FAQs

1. What is the main functional requirement in US 8,377,690?
   The blocking antibody must inhibit binding of human RANKL to human RANK (SEQ ID NO:6).

2. What structural narrowing appears in claim 2?
   The antibody binds RANKL fragments defined within SEQ ID NO:13: amino acids 69-317 or 162-317.

3. Why are these claims written as “cells that produce” rather than antibody compositions?
   The claim format shifts infringement toward proving the accused cell lines/expressing systems that produce the specified blocking antibodies.

4. Does claim 1 cover antibodies that bind only RANKL fragments?
   Claim 1 requires binding to “human RANKL polypeptide as set forth in SEQ ID NO:13,” so fragment-only binding can be captured only if it still corresponds to binding of the full SEQ ID NO:13 polypeptide.

5. How does the method-of-producing claims set relate to the cell claims?
   Claims 3 and 4 are derivative: they require culturing the corresponding cell from claims 1 or 2 to produce the blocking antibody.

References (APA)

[1] United States Patent No. 8,377,690. (2013). Blocking antibody to RANKL and methods of production. United States Patent and Trademark Office.

Details for Patent 8,377,690

Applicant	Tradename	Biologic Ingredient	Dosage Form	BLA	Approval Date	Patent No.	Expiredate
Amgen Inc.	PROLIA	denosumab	Injection	125320	June 01, 2010	8,377,690	2030-06-15
Amgen Inc.	XGEVA	denosumab	Injection	125320	November 18, 2010	8,377,690	2030-06-15

International Patent Family for US Patent 8,377,690

Country	Patent Number	Estimated Expiration
World Intellectual Property Organization (WIPO)	9958674
World Intellectual Property Organization (WIPO)	9828426
World Intellectual Property Organization (WIPO)	9828424