United States Patent 6,987,102: Claim Scope, Plerixafor Coverage, Expiration and Patent Landscape

U.S. Patent 6,987,102 covers methods for mobilizing progenitor and stem cells into peripheral blood by administering a CXCR4-binding compound and collecting the cells by apheresis. Its central commercial subject is plerixafor, also known as AMD3100 and marketed by Sanofi as Mozobil. The patent’s principal U.S. term has expired, eliminating current U.S. exclusionary rights from this patent, although related patents, regulatory exclusivities, manufacturing know-how and foreign rights may have affected market entry in other jurisdictions.

What does U.S. Patent 6,987,102 cover?

The patent claims a therapeutic and cell-collection method rather than plerixafor as a standalone chemical composition.

The core method requires:

Administering a defined bicyclam, polyamine or other CXCR4-binding compound.
Mobilizing progenitor or stem cells into peripheral blood.
Harvesting the cells by apheresis.

Independent claim 1 is directed to compounds having the general structure Z-linker-Z′, where the terminal groups include cyclic polyamines or specified nitrogen-containing aromatic structures. Independent claim 16 is broader in functional language and covers administration of any compound that binds CXCR4 in an amount sufficient to mobilize progenitor or stem cells, followed by apheresis (U.S. Patent No. 6,987,102, 2006).

The patent therefore has two principal claim architectures:

Claim group	Primary subject	Commercial relevance
Claims 1-15	Defined compound structures and administration methods	Directly covers plerixafor and related polyamine compounds
Claim 16	Functional CXCR4-binding compound method	Broad method claim potentially covering later CXCR4 antagonists
Claims 17-20	Mixed polyamine and aminomethyl-pyridine structures	Covers specific asymmetric analogues
Claims 21-22	Human use	Limits the relevant dependent claims to human subjects

The patent does not claim every use of a CXCR4 inhibitor. The claimed method requires mobilization into peripheral blood and subsequent harvesting by apheresis.

Which claims specifically cover plerixafor?

Claims 2, 3, 5, 6, 7 and 8 are the most directly relevant to plerixafor.

Plerixafor is the bicyclam compound:

1,1′-[1,4-phenylene-bis(methylene)]-bis-1,4,8,11-tetraazacyclotetradecane

That structure corresponds to the compound recited in claim 8. The claim requires:

Two cyclic polyamine terminal groups;
Identical Z and Z′ groups;
A 1,4-phenylene-bis-methylene linker;
A 14-membered tetraazacyclotetradecane ring system at each end.

The claim hierarchy operates as follows:

Claim	Limitation
Claim 1	Broad structural genus plus mobilization and apheresis
Claim 2	Both Z and Z′ are cyclic polyamines
Claim 3	Z and Z′ are identical
Claim 4	Z has 10-24 ring members and four nitrogen atoms
Claim 5	Z and Z′ are 1,4,8,11-tetraazacyclotetradecane
Claim 6	Linker includes an aromatic ring bracketed by methylene groups
Claim 7	Linker is 1,4-phenylene-bis-methylene
Claim 8	Specific plerixafor structure

A product using plerixafor to mobilize stem cells for apheresis would have been the clearest target of claim 8 during the patent term.

How broad is claim 16 for CXCR4-binding compounds?

Claim 16 is materially broader than claim 8 because it does not recite a specific chemical structure. It covers:

A compound that binds CXCR4;
Administration in an amount sufficient to mobilize progenitor or stem cells into peripheral blood;
Apheresis after administration.

The claim could potentially reach compounds outside the bicyclam family, including structurally distinct CXCR4 antagonists, if the accused method satisfies the functional limitations.

Its scope is constrained by several elements:

The compound must bind CXCR4.
The dosage must be sufficient to mobilize the claimed cells.
The method must involve harvesting by apheresis.
The claim is directed to a method of obtaining cells, not merely treating a patient.
The claim does not expressly require G-CSF, although G-CSF may be used in the commercial protocol.

The absence of a structural limitation creates potential claim-construction and validity issues. A defendant could challenge whether the specification adequately enables the full range of CXCR4-binding compounds covered by the claim or whether the claim has sufficient written-description support across that breadth. Those issues would depend on the patent specification, prosecution history, asserted construction and accused compound.

What formulations and dosing routes are protected?

The patent protects method conditions rather than a particular finished pharmaceutical formulation.

Claim 10 covers acid-addition salts, and claim 11 narrows that limitation to hydrochloride salts. Claim 12 covers intravenous or subcutaneous administration. Claim 13 recites a dosage range of approximately 0.1 micrograms/kg to 5 mg/kg.

These claims can be organized as follows:

Claim	Formulation or administration limitation
Claim 10	Acid-addition salt
Claim 11	Hydrochloride salt
Claim 12	Intravenous or subcutaneous administration
Claim 13	Approximately 0.1 micrograms/kg to 5 mg/kg
Claim 14	Co-administration of macrophage inflammatory protein
Claim 15	G-CSF administered before the claimed method

The claims do not require a particular excipient, container, concentration, injection volume or commercial dosage form. They also do not claim the Mozobil trade dress or a specific injectable formulation as such.

Mozobil is an injectable plerixafor product approved for use with G-CSF in stem-cell mobilization before collection by apheresis. The approved product is supplied as a sterile solution for subcutaneous injection, with a labeled concentration of 20 mg/mL (U.S. Food and Drug Administration, 2024).

Does the patent cover use with G-CSF?

Yes, but only claim 15 expressly requires prior administration of G-CSF.

The commercial Mozobil regimen uses plerixafor after pretreatment with G-CSF. A method that administers G-CSF before plerixafor could fall within claim 15 if the remaining elements are met. Claims 1 through 13 do not require G-CSF and can be practiced without that limitation.

Claim 14 recites macrophage inflammatory protein rather than G-CSF. That claim is narrower and would require the additional co-administration step.

The patent does not broadly claim all stem-cell mobilization regimens involving G-CSF. It claims G-CSF only in combination with the specified CXCR4-related mobilization method.

What is the FDA status of plerixafor?

The FDA approved Mozobil on December 15, 2008, under NDA 022311. The approved indication is use in combination with G-CSF to mobilize hematopoietic stem cells into peripheral blood for collection by apheresis and subsequent autologous transplantation in patients with non-Hodgkin lymphoma or multiple myeloma (U.S. Food and Drug Administration, 2008).

Regulatory item	Status
Active ingredient	Plerixafor
Original brand	Mozobil
Original sponsor	Genzyme Corporation, later part of Sanofi
FDA approval	December 15, 2008
NDA	022311
Route	Subcutaneous injection
Approved use	Stem-cell mobilization with G-CSF
Primary collection method	Apheresis
Product type	Small molecule
Biosimilar pathway	Not applicable

Plerixafor is not a biologic, so biosimilar approval rules do not apply. Follow-on competitors use the abbreviated new drug application pathway under Section 505(j) of the Federal Food, Drug, and Cosmetic Act.

What is the Orange Book status of U.S. Patent 6,987,102?

U.S. Patent 6,987,102 was associated with the U.S. patent estate for Mozobil and covered the clinical mobilization method rather than the active ingredient as a composition claim.

The patent issued on January 17, 2006. Its effective U.S. patent term expired in or around 2021, based on the patent family’s earliest relevant filing dates and applicable patent-term rules. The patent is therefore no longer an enforceable barrier to a U.S. generic using the claimed method.

Event	Date or period
Earliest reported priority period	2000-2001 patent family
U.S. patent issue	January 17, 2006
Patent number	6,987,102
Principal subject	CXCR4-mediated stem-cell mobilization
Effective U.S. expiration	Approximately 2021
Current exclusionary status	Expired

Orange Book status must be evaluated by product and listing history, not merely by the existence of the patent. A patent can be listed for an NDA and later become expired while remaining visible in historical Orange Book records. The expiration of this patent does not establish that every Mozobil-related patent expired on the same date.

When did plerixafor lose U.S. exclusivity?

Plerixafor lost the principal U.S. patent protection associated with U.S. Patent 6,987,102 in approximately 2021. The practical generic-entry date could have depended on:

The exact expiration date recorded for each listed patent;
Any patent-term adjustment;
Pediatric exclusivity;
ANDA litigation and settlement terms;
Other listed patents covering formulation, use or manufacturing;
Commercial decisions by generic applicants.

The compound’s earlier composition-of-matter protection was separate from the method claims in U.S. Patent 6,987,102. A composition patent covering bicyclam derivatives, including the AMD3100 family, was issued earlier and had a different expiration profile. A complete freedom-to-operate analysis therefore requires review of the full Orange Book and patent family rather than this patent alone.

Were there Paragraph IV challenges to this patent?

A Paragraph IV challenge would assert that a listed patent is invalid, unenforceable or not infringed by an ANDA product. For plerixafor, an ANDA applicant could challenge U.S. Patent 6,987,102 by arguing that:

The proposed product does not practice the claimed mobilization method;
The method is not performed by the ANDA applicant;
The claims are anticipated or obvious;
Claim 16 lacks adequate written-description or enablement support;
The patent does not cover the proposed label;
The patent was improperly listed or is expired.

Because the patent has expired, it no longer creates a present U.S. launch restriction. Historical Paragraph IV activity, if any, would have been relevant before expiration and would need to be assessed from FDA Orange Book records, ANDA litigation dockets and any notice letters.

What patent litigation affects plerixafor?

The principal legal risk during the active term was method-of-use enforcement against a generic or other party seeking approval for plerixafor stem-cell mobilization.

The risk profile differed by claim:

Claim category	Likely litigation theory
Claims 1-8	Direct infringement through plerixafor administration and apheresis
Claims 9-11	Structural variants, salt forms and hydrochloride forms
Claims 12-13	Route and dose-specific infringement
Claims 14-15	Combination treatment with macrophage inflammatory protein or G-CSF
Claim 16	Broad functional method claim covering CXCR4-binding compounds
Claims 17-20	Specific asymmetric CXCR4-binding analogues
Claims 21-22	Human-use limitations

For an ANDA case, the label and intended use would have been central. A label instructing use of plerixafor with G-CSF for stem-cell mobilization and apheresis would have created a stronger infringement theory than a label omitting the patented use.

No current enforcement right arises from an expired U.S. patent. Any surviving dispute would more likely involve damages for past conduct, ownership, regulatory records, or separate unexpired patents.

How strong was the patent estate?

The patent was commercially strong while active because claim 8 mapped directly to the clinical use of plerixafor. Its value came from the combination of:

A specific claim to the marketed bicyclam;
Apheresis as an expressly claimed step;
Human-use claims;
Subcutaneous and intravenous administration claims;
G-CSF combination coverage;
A broad functional CXCR4-binding method claim.

Its weaknesses were structural:

It was a method patent, not a broad composition-of-matter claim.
Infringement depended on practicing the mobilization and apheresis method.
Claim 16 used broad functional language that could face written-description and enablement challenges.
The patent did not independently block all manufacture, sale or possession of plerixafor.
Expiration ended its U.S. exclusionary value.

The strongest historical claim was claim 8 for the specific plerixafor method. Claim 16 had the largest theoretical scope but also presented the greatest validity and claim-construction exposure.

How does this patent compare with competing CXCR4 and stem-cell mobilization patents?

U.S. Patent 6,987,102 sits within a broader CXCR4 and hematopoietic stem-cell mobilization landscape.

Technology area	Typical claim focus	Relationship to 6,987,102
Bicyclam composition patents	Chemical compounds and salts	Earlier foundational protection for AMD3100-type compounds
CXCR4 antagonist methods	Use of antagonists for mobilization	Overlapping functional territory
Stem-cell mobilization regimens	G-CSF combinations, timing and patient selection	Potentially complementary or overlapping
Injectable formulations	Concentration, excipients and stability	Separate formulation protection
Cell-processing patents	Apheresis, enrichment and transplantation	Downstream technical coverage
CXCR4 antagonist discovery programs	New chemical entities and analogues	Potentially outside claim 8 but exposed to claim 16

The patent does not create biosimilar competition because plerixafor is a small molecule. Competitive entry is driven by generic drug regulation, active patent listings, manufacturing capability and commercial pricing.

What manufacturing and intellectual-property barriers remain?

After expiration, manufacturing barriers are primarily technical and regulatory rather than patent-based.

Plerixafor manufacture requires control of:

Multi-step synthesis of the bicyclic polyamine;
Regioselective formation of the bis-methylene phenylene linker;
Salt formation and purification;
Control of residual solvents and elemental impurities;
Analytical characterization of a highly polar, polycationic molecule;
Sterile injectable production;
Container-closure and stability qualification.

These issues can delay generic entry without preserving the expired patent’s exclusivity. Separate process patents, polymorph claims, formulation patents, trade secrets and regulatory exclusivities must be reviewed independently.

What generic launch risks exist?

The main U.S. launch risks are no longer centered on U.S. Patent 6,987,102 itself. The relevant risks are:

Other unexpired Orange Book patents.
Labeling that induces the patented use under a surviving method claim.
Product-specific formulation or manufacturing patents.
Patent litigation filed before the relevant expiration date.
FDA requirements for injectable product equivalence and quality.
Limited market size and price compression after entry.
Supply reliability for the active pharmaceutical ingredient and sterile fill-finish capacity.

Because the patent is expired, a generic plerixafor applicant generally would not need to wait for this patent before launching, subject to other listed rights and regulatory requirements.

What is the geographic scope of the patent?

U.S. Patent 6,987,102 has territorial effect only in the United States. It does not directly control:

European Union sales;
United Kingdom sales;
Canadian sales;
Japanese sales;
Australian sales;
Manufacturing performed entirely outside the United States.

Foreign patent family members may have covered corresponding compounds or methods, but each jurisdiction requires separate analysis of filing, grant, maintenance, term and legal status. A U.S. expiration does not establish foreign expiration.

Key Takeaways

U.S. Patent 6,987,102 is a method patent for CXCR4-mediated stem-cell mobilization followed by apheresis.
Claim 8 most directly covers the plerixafor mobilization method.
Claim 16 is the broadest claim because it covers a CXCR4-binding compound without requiring a specific chemical structure.
Claims 12 and 13 cover intravenous or subcutaneous administration and a defined dosage range.
Claim 15 covers mobilization after prior G-CSF administration.
Mozobil, the commercial plerixafor product, was FDA-approved in 2008 under NDA 022311.
The principal U.S. patent term expired in approximately 2021.
Plerixafor is a small molecule, so biosimilar rules do not apply.
Current U.S. generic risk depends on other patents, regulatory requirements, manufacturing capability and commercial economics rather than this expired patent.
Foreign patent status cannot be inferred from the U.S. patent’s expiration.

FAQs

Is U.S. Patent 6,987,102 a composition patent for plerixafor?

No. It primarily claims methods of administering plerixafor or other CXCR4-binding compounds to mobilize stem cells followed by apheresis. Claim 8 identifies the plerixafor structure within that method.

Does the patent cover plerixafor use without apheresis?

The asserted claims require harvesting progenitor or stem cells by apheresis. Administration of plerixafor without the claimed harvesting step would not satisfy the complete method claims as written.

Does G-CSF alone infringe U.S. Patent 6,987,102?

No. G-CSF alone does not satisfy the CXCR4-binding compound limitation. Claim 15 covers G-CSF used before the patented CXCR4-mediated mobilization method.

Is plerixafor eligible for a biosimilar application?

No. Plerixafor is a chemically synthesized small molecule. A follow-on product generally proceeds through the ANDA pathway rather than the biosimilar pathway.

Can a generic launch after expiration of U.S. Patent 6,987,102?

Yes, expiration removes this patent as a current U.S. barrier. The applicant must still address any other listed patents, regulatory exclusivities, label issues and product-specific intellectual-property rights.

References

U.S. Patent No. 6,987,102. (2006). Methods for mobilizing stem cells. United States Patent and Trademark Office.
U.S. Food and Drug Administration. (2008). Mozobil (plerixafor) injection, prescribing information. FDA.
U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations. FDA.
United States Congress. (1984). Drug Price Competition and Patent Term Restoration Act of 1984, Pub. L. No. 98-417, 98 Stat. 1585.
United States Patent and Trademark Office. (2024). Patent term adjustment and patent term extension guidance. USPTO.

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
European Patent Office	1411918	⤷ Start Trial	C300537	Netherlands	⤷ Start Trial
European Patent Office	1411918	⤷ Start Trial	CA 2012 00026	Denmark	⤷ Start Trial
European Patent Office	1411918	⤷ Start Trial	PA2012011	Lithuania	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 6,987,102

Summary for Patent: 6,987,102