Details for Patent: 8,865,937

Which drugs does patent 8,865,937 protect, and when does it expire?

Patent 8,865,937 protects FETZIMA and is included in one NDA.

This patent has eight patent family members in four countries.

Summary for Patent: 8,865,937

Title:	Crystalline forms of (1S,2R)-2-(amino methyl)-N,N-diethyl-1-phenyl cyclopropane carboxamide
Abstract:	The present invention relates to novel crystalline forms of (1S,2R)-2-(amino methyl)-N,N-diethyl-1-phenyl cyclopropane carboxamide. Processes for the preparation of this form, compositions containing the form, and methods of use thereof are also described.
Inventor(s):	Mahendra G. Dedhiya, Rahul Surana
Assignee:	Forest Laboratories Holdings ULC
Application Number:	US12/941,293
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 8,865,937
Patent Claim Types: see list of patent claims	Composition; Compound; Process; Dosage form;

US Patent 8,865,937: Levomilnacipran Hydrochloride Crystal Form, Formulation, and Generic Entry Analysis

US Patent 8,865,937 protects a specific crystalline form of levomilnacipran hydrochloride, the active pharmaceutical ingredient in Fetzima extended-release capsules. Its claims cover the crystal itself, pharmaceutical compositions containing it, sustained-release dosage strengths of 20 mg, 40 mg, 80 mg, and 120 mg, and an ethanol-based crystallization process. The patent does not broadly control all levomilnacipran hydrochloride, all levomilnacipran formulations, or every manufacturing route.

The patent's principal commercial value is its potential to block an ANDA product that uses the claimed polymorph in an extended-release capsule. Its strength depends on the scope of the XRPD limitations, the ability to prove polymorph identity in an accused product, and the status of related patents and Orange Book listings.

What drug and product does US Patent 8,865,937 protect?

US 8,865,937 covers the hydrochloride salt of levomilnacipran, chemically identified as:

(1S,2R)-2-(aminomethyl)-N,N-diethyl-1-phenylcyclopropane carboxamide hydrochloride.

Levomilnacipran is the active enantiomer of milnacipran and is a serotonin-norepinephrine reuptake inhibitor. Fetzima is an FDA-approved extended-release capsule marketed for major depressive disorder. The FDA-approved dosage strengths are 20 mg, 40 mg, 80 mg, and 120 mg, matching the dosage limitations in claims 7 through 10 of the patent.[1]

Patent identification

Item	Data
Patent	US 8,865,937 B2
Patent type	Polymorph, pharmaceutical composition, and manufacturing-process patent
Active ingredient	Levomilnacipran hydrochloride
Product association	Fetzima extended-release capsules
Issue date	October 21, 2014
Patent holder history	Originator rights associated with Pierre Fabre and subsequently commercialized through Forest Laboratories, Allergan, and AbbVie corporate structures
Core technology	Crystalline levomilnacipran hydrochloride identified by XRPD, DSC, and Raman characteristics
Main commercial concern	Generic levomilnacipran ER products using the claimed crystalline form

What are the independent claims in US Patent 8,865,937?

The patent has three substantive claim groups.

Claim 1 is the primary product claim. It covers a crystalline form identified by three XRPD peaks:

• 12.0 ± 0.2 degrees 2θ
• 20.1 ± 0.2 degrees 2θ
• 22.5 ± 0.2 degrees 2θ

Claim 5 is the principal pharmaceutical-composition claim. It covers a composition containing a pharmaceutically acceptable carrier and an active ingredient comprising the same crystalline form.

Claim 14 is the principal process claim. It requires:

1. Dissolving levomilnacipran hydrochloride in a solvent comprising substantially pure ethanol; and
2. Precipitating the claimed crystalline form.

Claims 2 through 4 narrow the crystal by adding further analytical characteristics. Claims 6 through 13 narrow the composition by adding XRPD, dosage, and polymorph-content limitations. Claims 15 and 16 narrow the process based on ethanol concentration. Claim 17 is a product-by-process claim.

How broad is the crystalline-form claim?

Claim 1 is narrower than a conventional chemical compound claim. It does not cover the levomilnacipran hydrochloride molecule in every physical form. It covers only a crystal that exhibits the specified XRPD pattern.

The practical scope can be summarized as follows:

Product characteristic	Covered by claim 1?
Levomilnacipran hydrochloride in any solid form	No
Amorphous levomilnacipran hydrochloride	No, unless it nevertheless produces the claimed XRPD pattern
A different polymorph	Generally no
The claimed crystalline form with the three required peaks	Yes, if the peaks fall within the stated tolerances
A mixture containing the claimed form	Potentially, subject to proof that the claimed form is present
A free-base form	No
A different salt	No
Racemic milnacipran hydrochloride	No, because the claims specify the (1S,2R) stereoisomer

The claim is therefore analytically defined rather than purely structurally defined. In an infringement dispute, XRPD testing would likely be central. The relevant question would be whether the accused material exhibits the three required peaks at the claimed positions, not whether the manufacturer uses the same trade name or synthetic route.

What do the dependent crystal claims add?

Claim 2 adds a peak at approximately 29.2 degrees 2θ. Claim 3 adds a melting endotherm at approximately 200°C by DSC. Claim 4 adds Raman peaks at approximately 695, 735, and 1435 cm−1.

These claims create multiple analytical routes for characterizing the solid form, but they do not materially broaden claim 1. They are fallback positions. If an accused product falls outside the additional DSC or Raman limitations, it may still infringe claim 1 if the three required XRPD peaks are present.

What formulations are protected by US 8,865,937?

Claims 5 through 13 cover pharmaceutical compositions containing the claimed crystalline form. The composition claims are broader than claims 7 through 10 because claim 5 does not require a specific dosage form or dose.

The patent expressly covers sustained-release tablets or capsules containing approximately:

• 20 mg
• 40 mg
• 80 mg
• 120 mg

Those strengths correspond to Fetzima's marketed extended-release strengths. The composition claims also include polymorph-content thresholds of greater than approximately 20%, 60%, and 90% by weight.

Composition claim scope

Claim	Main limitation
5	Pharmaceutical composition containing carrier and claimed crystal
6	Composition also having the 29.2-degree XRPD peak
7	Sustained-release tablet or capsule, about 20 mg
8	Sustained-release tablet or capsule, about 40 mg
9	Sustained-release tablet or capsule, about 80 mg
10	Sustained-release tablet or capsule, about 120 mg
11	More than about 20 wt.% claimed crystal
12	More than about 60 wt.% claimed crystal
13	More than about 90 wt.% claimed crystal

A generic product could face different infringement outcomes depending on its polymorph content. A formulation containing only an alternative polymorph may avoid the crystal limitations. A formulation containing a mixture may still create risk if the claimed crystal is present in the product and the applicable claim does not impose a higher purity threshold.

Claims 7 through 10 are commercially important but relatively narrow. A product with a dose outside the listed strengths could avoid those claims while remaining exposed to claim 5 or other patents covering levomilnacipran formulations.

What manufacturing process is protected?

Claim 14 covers crystallization from substantially pure ethanol. Claims 15 and 16 specify ethanol concentrations above 96% and 98% by weight.

The process claims do not cover every process that produces the claimed polymorph. A manufacturer using water, isopropanol, acetone, a mixed solvent, or another crystallization route may avoid literal infringement of claim 14 if the process does not include the required substantially pure ethanol limitation.

Process element	Required under claim 14
Starting material is levomilnacipran hydrochloride	Yes
Solvent includes substantially pure ethanol	Yes
Dissolution step	Yes
Precipitation step	Yes
Ethanol above 96%	Claim 15
Ethanol above 98%	Claim 16

The process claims can be valuable where manufacturing information becomes available through discovery, regulatory filings, inspection records, supplier documentation, or batch records. They are less useful when the generic manufacturer can produce the same crystal through a non-infringing route.

How should claim 17 be interpreted?

Claim 17 covers a crystalline form prepared by the process of claims 15 or 16. This is a product-by-process limitation. Its scope may depend on whether the relevant court treats the process language as limiting the product claim or merely describing the product's origin.

Claim 17 is also narrower than claim 1 in practical litigation terms because the patentee may need to establish both the product identity and the claimed preparation route, depending on the governing interpretation. A generic manufacturer could reduce risk by using a non-ethanol crystallization process and maintaining documentation showing that route.

When does US Patent 8,865,937 expire?

The patent issued on October 21, 2014. Its nominal term is generally calculated from the earliest effective nonprovisional or international filing date, subject to patent-term adjustment, terminal disclaimers, and any applicable patent-term extension.

Public patent records associate the patent with a 2011 international or nonprovisional filing framework and an earlier priority date. On that basis, the ordinary term is expected to run into approximately 2031, subject to the official USPTO term calculation. The issue date is not the expiration date.

Exclusivity component	Relevance to Fetzima
New-drug exclusivity	FDA approval of Fetzima occurred in 2013
Patent term	US 8,865,937 extends beyond the initial approval period
Orange Book status	The FDA Orange Book is the controlling source for listed patent and expiration data
Pediatric extension	No conclusion should be drawn without the applicable Orange Book entry and patent-term records
Patent-term adjustment	Must be checked in the USPTO record before relying on a precise launch date

The FDA approved Fetzima on July 26, 2013. The product's five-year new-chemical-entity exclusivity period therefore expired in 2018, but patent protection can continue substantially longer.[1][2]

What is the Orange Book status of Fetzima and levomilnacipran?

The Orange Book determines which patents an ANDA applicant must address for an FDA-listed reference product. Patent 8,865,937 is the type of polymorph and formulation patent that can be listed against an extended-release levomilnacipran product if it meets FDA listing requirements.

An Orange Book listing does not establish that every claim is valid or infringed. It creates a regulatory patent-certification consequence for an ANDA applicant.

Potential ANDA certifications include:

• Paragraph I, if no patent information is listed
• Paragraph II, if the listed patent has expired
• Paragraph III, if the applicant will wait until expiration
• Paragraph IV, if the applicant asserts that the patent is invalid, unenforceable, or will not be infringed
• A section viii statement, where the applicant seeks approval without the patented method of use

For a polymorph patent, a Paragraph IV strategy could challenge claim construction, analytical identity, written description, enablement, anticipation, obviousness, or the relationship between the listed patent and the proposed generic product.

Which companies are challenging Fetzima patents?

A reliable assessment of named challengers requires current FDA ANDA records and federal court dockets. Patent 8,865,937 itself does not identify an ANDA filer, Paragraph IV notice, lawsuit, or settlement.

The relevant competitive group consists of generic manufacturers capable of developing levomilnacipran extended-release capsules. Potential risk typically comes from companies with CNS generic portfolios and controlled-release manufacturing capabilities. The existence of a generic product, an ANDA filing, or an FDA approval cannot be inferred solely from the issuance of US 8,865,937.

The key litigation trigger is a Paragraph IV notice followed by a suit filed within 45 days. If suit is timely filed, FDA approval may be subject to a 30-month stay under the Hatch-Waxman framework, subject to statutory exceptions.[3]

What patent litigation affects levomilnacipran?

The patent is potentially litigable on five principal grounds:

1. Claim construction: Whether XRPD peak tolerances define the claimed form with adequate precision.
2. Anticipation: Whether an earlier reference disclosed the same crystal, even without the same analytical labels.
3. Obviousness: Whether crystallization screening and ethanol recrystallization would have made the claimed form predictable or routine.
4. Enablement and written description: Whether the specification adequately supports the claimed analytical and composition ranges.
5. Infringement proof: Whether testing demonstrates that an ANDA product contains the claimed crystal.

A generic manufacturer may seek a non-infringement position by using an alternative polymorph, an amorphous material, a different salt, or a different manufacturing solvent. That approach must be reconciled with the reference product's required pharmaceutical performance and FDA product-specific expectations.

How strong is the patent estate for levomilnacipran?

US 8,865,937 is strongest against a generic that:

• Uses the same levomilnacipran hydrochloride crystal;
• Markets one of the four Fetzima dose strengths;
• Uses a sustained-release capsule or tablet;
• Produces the crystal by high-purity ethanol precipitation; or
• Includes more than 90% of the claimed crystal form.

It is weaker against a generic that uses:

• A distinct polymorph;
• An amorphous solid;
• A different salt or free base;
• A different dosage form;
• A crystallization route without high-purity ethanol; or
• A formulation that does not contain the claimed crystalline form.

The patent is not a composition-of-matter patent on levomilnacipran itself. The original compound and therapeutic-use patent estate must be analyzed separately. Core compound protection generally carries greater blocking power than a polymorph patent because an alternative solid form may still infringe the underlying molecule or method claims.

What generic launch scenarios exist?

Scenario	Likely result
Paragraph III certification	Launch delayed until patent expiration
Paragraph IV with no timely suit	FDA approval may proceed after applicable regulatory periods
Paragraph IV with timely infringement suit	Possible 30-month stay
Non-infringing polymorph	Potential launch after regulatory approval, subject to other patents
Same polymorph, different process	Process claim may be avoided, but product and composition claims remain
Alternative formulation	Claims 7 through 10 may be avoided, but claim 5 or other patents may remain relevant
Patent invalidated or narrowed	Earlier generic entry becomes possible
Settlement agreement	Launch date depends on confidential and public settlement terms

Does US 8,865,937 create biosimilar risk?

No. Biosimilar law is not the relevant pathway because levomilnacipran is a small-molecule drug. Competitive entry would normally occur through an ANDA under section 505(j) of the Federal Food, Drug, and Cosmetic Act, not through a biosimilar application under section 351(k) of the Public Health Service Act.

What licensing deals affect the patent landscape?

Levomilnacipran originated with Pierre Fabre. Forest Laboratories developed and commercialized Fetzima in the United States. Forest later became part of Actavis, Actavis became part of Allergan, and AbbVie acquired Allergan in 2020.

Those corporate transactions establish commercial continuity but do not, by themselves, disclose the terms of patent licenses, royalty obligations, territorial rights, or settlement agreements. Patent ownership and commercial license rights should be separated when assessing enforcement authority and revenue exposure.

What geographic coverage does the patent provide?

US 8,865,937 provides protection only in the United States. Parallel rights may exist in other jurisdictions through the same international patent family, but foreign claims, expiration dates, prosecution histories, and validity positions must be assessed separately.

A US design-around does not establish freedom to operate in Europe, Canada, Japan, China, or other markets. The relevant risks include:

• Different polymorph claim language;
• Different patent-term calculations;
• National-phase prosecution outcomes;
• Supplementary protection certificates in Europe;
• Local product-by-process standards; and
• Different rules for pharmaceutical patent listing and generic litigation.

Key Takeaways

• US 8,865,937 is a polymorph, formulation, and process patent for levomilnacipran hydrochloride.
• Claim 1 requires three specified XRPD peaks and does not cover all forms of levomilnacipran.
• Claims 5 through 13 target pharmaceutical compositions, including Fetzima-like sustained-release strengths of 20 mg, 40 mg, 80 mg, and 120 mg.
• Claims 14 through 16 target crystallization using substantially pure ethanol, with dependent thresholds above 96% and 98%.
• Claim 17 is a narrower product-by-process claim.
• The patent is potentially important for generic levomilnacipran ER products but does not provide compound-level protection.
• ANDA applicants may use Paragraph IV certifications, alternative polymorphs, or non-ethanol manufacturing routes to reduce exposure.
• FDA Orange Book listings and current USPTO term data control the precise regulatory and expiration analysis.
• Biosimilar law is not applicable.
• The patent's commercial blocking strength depends on whether the proposed generic contains the claimed crystal and whether related levomilnacipran patents remain enforceable.

FAQs

Can a generic avoid US 8,865,937 by using amorphous levomilnacipran hydrochloride?

Potentially. An amorphous material ordinarily would not satisfy a claim requiring the specified XRPD peaks. The generic would still need to satisfy FDA performance, stability, and manufacturing requirements.

Does a different salt avoid the patent?

Generally yes, because the claims specify levomilnacipran hydrochloride. A different salt would not ordinarily meet the claimed chemical identity, although other patents could cover that salt or its use.

Does using less than 96% ethanol avoid every claim?

No. It may avoid dependent claim 15 and possibly claim 16, but it does not necessarily avoid claim 14 if the solvent remains "substantially pure ethanol." Product and composition claims are independent of the claimed ethanol concentration.

Can the crystal be detected in a finished extended-release capsule?

Usually, yes, through analytical testing such as XRPD, supported where necessary by DSC, Raman spectroscopy, microscopy, or solid-state characterization. Excipients and low polymorph content can complicate testing.

Is Fetzima's 120 mg strength separately protected?

Claim 10 specifically covers a sustained-release tablet or capsule comprising approximately 120 mg of the active ingredient and the claimed crystal. That claim is narrower than claim 5 and does not determine the scope of every other patent covering Fetzima.

References

1. U.S. Food and Drug Administration. (2013). Fetzima (levomilnacipran hydrochloride) extended-release capsules: Prescribing information.
2. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book.
3. U.S. Patent and Trademark Office. (2014). U.S. Patent No. 8,865,937 B2: Crystalline form of (1S,2R)-2-(aminomethyl)-N,N-diethyl-1-phenylcyclopropane carboxamide hydrochloride.
4. U.S. Congress. (1984). Drug Price Competition and Patent Term Restoration Act of 1984, Pub. L. No. 98-417.

Drugs Protected by US Patent 8,865,937

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Abbvie	FETZIMA	levomilnacipran hydrochloride	CAPSULE, EXTENDED RELEASE;ORAL	204168-001	Jul 25, 2013	AB	RX	Yes	No			Y	Y
Abbvie	FETZIMA	levomilnacipran hydrochloride	CAPSULE, EXTENDED RELEASE;ORAL	204168-002	Jul 25, 2013	AB	RX	Yes	No			Y	Y
Abbvie	FETZIMA	levomilnacipran hydrochloride	CAPSULE, EXTENDED RELEASE;ORAL	204168-003	Jul 25, 2013	AB	RX	Yes	No			Y	Y
Abbvie	FETZIMA	levomilnacipran hydrochloride	CAPSULE, EXTENDED RELEASE;ORAL	204168-004	Jul 25, 2013	AB	RX	Yes	Yes			Y	Y

International Family Members for US Patent 8,865,937

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Canada	2779711
Canada	2790933
European Patent Office	2496079
European Patent Office	2536688
Japan	2013510176
Japan	2013517290
World Intellectual Property Organization (WIPO)	2011057176