United States Patent 11,311,500: Esketamine Intranasal Dosing Claims, Exclusivity and Patent Landscape
U.S. Patent No. 11,311,500 protects specific intranasal esketamine treatment regimens for major depressive disorder. Its core limitations are a 56 mg or 84 mg esketamine dose, twice-weekly administration for approximately four weeks, and, for claims 12-22, subsequent maintenance dosing once weekly or once every two weeks. The claims cover both treatment-resistant depression and major depressive disorder with suicidal ideation or behavior, with several dependent claims requiring adjunctive oral antidepressant therapy and esketamine hydrochloride.
The patent is directed to the dosing and treatment schedule used for Janssen’s Spravato product, not to esketamine as a molecule in the abstract. A competing product or regimen must satisfy every limitation of an asserted claim to create literal infringement risk.
What drug and FDA product are covered by U.S. Patent 11,311,500?
The claimed active ingredient is (S)-2-(2-chlorophenyl)-2-(methylamino)cyclohexanone, commonly known as esketamine. The claims expressly cover esketamine and pharmaceutically acceptable salts, including esketamine hydrochloride.
The commercial product most closely aligned with the claims is Spravato, an intranasal esketamine product marketed by Janssen Pharmaceuticals, a Johnson & Johnson company.
| Item |
Details |
| Active ingredient |
Esketamine, the S-enantiomer of ketamine |
| Commercial product |
Spravato |
| Dosage form |
Intranasal aqueous spray |
| FDA application |
NDA 211243 |
| FDA initial approval |
March 5, 2019 |
| Initial indication |
Treatment-resistant depression in adults |
| Later indication |
Depressive symptoms in adults with major depressive disorder and acute suicidal ideation or behavior |
| Administration setting |
Certified healthcare setting under a REMS program |
| Key claimed doses |
56 mg or 84 mg |
| Claimed induction frequency |
Twice weekly |
| Claimed induction duration |
Approximately four weeks |
| Claimed maintenance frequency |
Once weekly or once every two weeks |
FDA approval and labeling requirements are separate from patent scope. The patent claims require particular dosing conduct, while the FDA label controls lawful product use, administration setting, monitoring, and indication-specific prescribing requirements (U.S. Food and Drug Administration [FDA], 2019, 2020).
What are the independent claims in Patent 11,311,500?
Claims 1 and 12 are the principal independent claims.
Claim 1: induction-only regimen
Claim 1 requires:
- A human patient with major depressive disorder.
- Intranasal administration.
- An aqueous formulation.
- Esketamine or a pharmaceutically acceptable salt.
- A therapeutically effective amount of approximately 56 mg or 84 mg.
- An induction phase lasting approximately four weeks.
- Administration twice per week during that induction phase.
Claim 1 does not require:
- Treatment-resistant depression.
- Suicidal ideation or behavior.
- Adjunctive antidepressant therapy.
- Esketamine hydrochloride specifically.
- A maintenance phase.
- A particular nasal-device design.
- A specific concentration, excipient, or spray volume.
This breadth makes claim 1 the principal risk claim for a product used according to the standard Spravato induction schedule.
Claim 12: induction-plus-maintenance regimen
Claim 12 contains all the limitations of claim 1 and adds a maintenance phase. It requires:
- Induction dosing of 56 mg or 84 mg twice weekly for approximately four weeks; and
- Maintenance dosing of 56 mg or 84 mg once weekly or once every two weeks.
Claim 12 therefore has a narrower temporal structure than claim 1. A product administered only during induction may implicate claim 1 but not claim 12. A product administered under both phases may implicate both claims.
How do dependent claims narrow the patent scope?
Claims 2-11 and 13-22 add treatment context, concomitant therapy, salt form, or maintenance requirements.
| Claims |
Added limitation |
| 2 |
Adjunctive treatment with one or more antidepressants during induction |
| 3 |
The antidepressant is oral |
| 4 |
MDD with suicidal ideation or behavior |
| 5 |
Esketamine hydrochloride during induction |
| 6 |
Treatment-resistant depression |
| 7 |
Esketamine hydrochloride during induction |
| 8 |
MDD with suicidal ideation or behavior |
| 9 |
Esketamine hydrochloride during induction |
| 10 |
Treatment-resistant depression |
| 11 |
Esketamine hydrochloride during induction |
| 13 |
Adjunctive antidepressant during induction and maintenance |
| 14 |
The antidepressant is oral |
| 15 |
MDD with suicidal ideation or behavior |
| 16 |
Esketamine hydrochloride in both phases |
| 17 |
Treatment-resistant depression |
| 18 |
Esketamine hydrochloride in both phases |
| 19 |
MDD with suicidal ideation or behavior |
| 20 |
Esketamine hydrochloride in both phases |
| 21 |
Treatment-resistant depression |
| 22 |
Esketamine hydrochloride in both phases |
The dependent claims are useful for litigation and licensing because they create multiple fallback positions. If a broader claim is challenged, a patent owner may rely on narrower combinations involving treatment-resistant depression, suicidal ideation, oral antidepressant use, or the hydrochloride salt.
What formulation is protected by Patent 11,311,500?
The claims require an aqueous intranasal formulation, but they do not recite a detailed excipient system or specific concentration. The formulation must contain esketamine or a pharmaceutically acceptable salt and must be administered intranasally in a way that delivers the claimed dose.
The patent therefore primarily protects use of the formulation in a specified therapeutic schedule. It is not, based on the supplied claims, a conventional composition claim covering every aqueous esketamine formulation.
Formulation elements not expressly required
The claims do not expressly require:
- A particular pH.
- A specific preservative.
- A specific buffer.
- A defined viscosity.
- A particular pump or actuator.
- A fixed number of sprays.
- A specific esketamine concentration.
- A specific volume per spray.
A competing formulation could avoid some formulation-specific patent claims in the broader Spravato estate while still infringing Patent 11,311,500 if it is aqueous, intranasal, contains esketamine, and is used under the claimed dosing schedule.
What methods of treatment are protected?
The patent protects method-of-treatment conduct rather than manufacture or sale of esketamine as such.
Treatment-resistant depression
Claims 6, 7, 10, 11, 17, 18, 21, and 22 cover treatment-resistant depression. The relevant regimen remains twice-weekly induction for about four weeks, with optional or required maintenance depending on the claim.
Major depressive disorder with suicidal ideation or behavior
Claims 4, 5, 8, 9, 15, 16, 19, and 20 cover MDD with suicidal ideation or behavior. The claims do not require that the patient be hospitalized, that the suicidal symptoms reach a particular severity, or that a specific rating-scale threshold be met.
Adjunctive antidepressant therapy
Claims 2, 3, 13, and 14 require adjunctive treatment with one or more antidepressants. Claims 3 and 14 narrow the adjunctive therapy to oral antidepressants.
These claims align closely with the clinical context in which Spravato is administered with an oral antidepressant for treatment-resistant depression. A regimen using esketamine as monotherapy could fall outside these dependent claims while remaining within claim 1 or claim 12.
When does Patent 11,311,500 lose exclusivity?
The patent issued on April 26, 2022, as U.S. Patent No. 11,311,500. Its nominal expiration is generally calculated from the earliest effective nonprovisional or international filing date in the priority chain, subject to patent-term adjustment and any applicable terminal disclaimer.
The patent family is associated with a 2015 priority date, producing a nominal term extending into November 2035. The exact enforceable expiration date should be taken from the USPTO patent-term data and the FDA Orange Book listing, because patent-term adjustment can alter the ordinary 20-year calculation.
| Event |
Date or period |
| Earliest reported priority period |
November 2015 |
| U.S. grant |
April 26, 2022 |
| Nominal 20-year term |
Approximately November 2035 |
| Patent-term adjustment |
Must be verified in the USPTO record |
| FDA pediatric extension |
No extension is established from the supplied claims |
| Patent-term extension under 35 U.S.C. § 156 |
No extension is established from the supplied claims |
The patent’s economic importance depends less on the underlying chemical exclusivity than on whether it remains listed against Spravato and whether a generic applicant must address it in an abbreviated new drug application.
What is the Orange Book status of Patent 11,311,500?
Spravato is an NDA product subject to Orange Book patent listing. Orange Book-listed patents can require an ANDA applicant to submit a Paragraph IV certification if the applicant seeks approval before the listed patent expires.
The practical Orange Book analysis has four parts:
- Whether Patent 11,311,500 is listed for NDA 211243.
- Whether the applicant’s proposed label includes the patented induction or maintenance regimen.
- Whether the patent is eligible for a method-of-use listing under FDA regulations.
- Whether the applicant can use a section viii statement to carve out the patented use.
A section viii carve-out may reduce infringement exposure if the proposed label omits the patented indication or regimen. It does not eliminate risk where the generic label, physician instructions, promotional conduct, or foreseeable use directs administration according to the patented schedule.
The patent’s claims are particularly relevant to an ANDA because the 56 mg and 84 mg doses and twice-weekly induction schedule are central elements of the approved Spravato regimen.
Are there Paragraph IV challenges to Patent 11,311,500?
A Paragraph IV challenge would require an ANDA applicant to assert that the patent is invalid, unenforceable, or not infringed. The supplied patent claims do not identify any challenger, notice letter, district-court action, or settlement.
Potential Paragraph IV positions include:
- Anticipation based on earlier esketamine dosing disclosures.
- Obviousness based on ketamine, esketamine, and depression-treatment literature.
- Written-description or enablement challenges to the claimed regimen.
- Noninfringement based on a different dose, frequency, induction duration, or maintenance schedule.
- Noninfringement based on a nonaqueous or nonintranasal formulation.
- Label-based defenses involving a section viii carve-out.
The strongest infringement case would involve an intranasal aqueous esketamine product labeled for 56 mg or 84 mg twice weekly for four weeks and then once weekly or every two weeks. A product labeled only for a different dose or frequency would have a stronger noninfringement position, although induced-use and off-label-use theories could remain relevant.
Which companies are challenging Spravato exclusivity?
The supplied materials do not identify a confirmed Paragraph IV challenger or settlement agreement involving Patent 11,311,500.
The competitive threat is more likely to arise from three sources:
| Competitive route |
Patent risk |
| Generic intranasal esketamine |
High if the label tracks Spravato dosing |
| Competing ketamine or esketamine formulation |
Depends on route, salt, dose, and schedule |
| Non-esketamine rapid-acting antidepressant |
Usually avoids direct infringement but competes commercially |
| Compounded intranasal ketamine |
May avoid this patent’s esketamine limitation but raises separate regulatory and enforcement issues |
| Injectable or oral esketamine |
May avoid the intranasal limitation but could implicate other patents |
No biosimilar pathway applies because esketamine is a small-molecule drug, not a biological product. The relevant abbreviated pathway is an ANDA or, for a materially different product, a 505(b)(2) application.
How strong is the patent estate for Spravato?
Patent 11,311,500 is commercially significant because it covers the labeled treatment architecture rather than only a peripheral formulation feature. Its strength has four main components.
Strengths
- It covers the standard 56 mg and 84 mg dosing levels.
- It covers twice-weekly induction for approximately four weeks.
- It covers both treatment-resistant depression and suicidal-ideation populations through dependent claims.
- It extends to maintenance dosing once weekly or every two weeks.
- It covers esketamine hydrochloride, the commercially relevant salt.
- It does not require adjunctive antidepressant therapy in the broad independent claims.
Vulnerabilities
- The claims are method claims and require proof of actual or directed use.
- “About” language creates potential claim-construction disputes around dose and duration.
- Prior-art risk may focus on clinical-trial protocols and published esketamine regimens.
- A competitor may design around the frequency, dose, route, or induction duration.
- A label carve-out may reduce formal infringement exposure.
- The patent does not, based on the supplied claims, independently protect every composition, device, manufacturing process, or delivery-system feature.
The estate is strongest when combined with separate patents covering the active ingredient, formulation, device, manufacturing process, and additional dosing or indication claims.
What generic launch scenarios exist?
Scenario 1: Full-label generic launch
A generic applicant seeks approval for treatment-resistant depression and uses the 56 mg or 84 mg twice-weekly induction regimen. This creates the highest exposure under claims 1, 6, 10, and related dependent claims, as well as claim 12 if maintenance dosing is included.
Scenario 2: Section viii carve-out
The applicant omits one patented indication or maintenance regimen. This may reduce exposure to certain dependent claims but does not necessarily avoid claim 1, which broadly covers MDD.
Scenario 3: Alternative dosing regimen
A product uses a different dose or frequency. This may avoid literal infringement, although the commercial value of the product could decline if it no longer matches the established clinical regimen.
Scenario 4: 505(b)(2) product
A sponsor develops a modified esketamine formulation, device, concentration, or administration schedule. The sponsor may avoid some claims but would face separate patent, clinical, and regulatory barriers.
What patent litigation and settlements affect the product?
The supplied claims contain no litigation history or settlement terms. Patent litigation risk would likely center on:
- Claim construction of “about 56 mg” and “about 84 mg.”
- The meaning of “about four weeks.”
- Whether a product’s label directs twice-weekly dosing.
- Whether maintenance dosing is required for infringement of claim 12.
- Whether a generic label can omit the patented use.
- Obviousness over clinical studies and published esketamine protocols.
- The scope of “aqueous formulation” and pharmaceutically acceptable salt.
A settlement involving a Paragraph IV challenger could establish an agreed generic launch date before patent expiry, but no such date is established by the supplied material.
What manufacturing and geographic barriers remain?
Patent 11,311,500 does not directly claim a manufacturing process. Manufacturing barriers instead arise from other parts of the broader patent and regulatory estate, including:
- Production of enantiomerically enriched esketamine.
- Control of impurity profiles.
- Stable aqueous nasal formulations.
- Dose-delivery accuracy.
- Device compatibility.
- Container-closure integrity.
- Commercial-scale sterile or controlled manufacturing.
- REMS-compliant distribution and administration.
The patent is a U.S. right. Parallel protection in Europe, Japan, Canada, and other jurisdictions depends on the corresponding national family members, their prosecution histories, claim amendments, and local term calculations. A U.S. noninfringement position does not establish freedom to operate elsewhere.
Key Takeaways
- Patent 11,311,500 is a regimen patent for intranasal esketamine treatment of MDD.
- The core regimen is 56 mg or 84 mg twice weekly for approximately four weeks.
- Claims 12-22 add maintenance dosing once weekly or once every two weeks.
- The claims cover treatment-resistant depression and MDD with suicidal ideation or behavior.
- Several dependent claims require oral antidepressant therapy and esketamine hydrochloride.
- The patent is closely aligned with Spravato’s approved dosing architecture.
- The nominal patent term extends into approximately November 2035, subject to USPTO term adjustments.
- Generic risk is highest for an ANDA label that reproduces Spravato’s dose and schedule.
- A biosimilar pathway is irrelevant because esketamine is a small molecule.
- The claims do not independently establish protection for every formulation, device, manufacturing process, or international counterpart.
FAQs
Does Patent 11,311,500 cover esketamine itself?
No. The supplied claims cover methods of treating MDD using intranasal esketamine under specified dosing schedules. They do not claim esketamine as a molecule in isolation.
Can a competitor avoid the patent by using racemic ketamine?
Potentially, with respect to these claims, because the claims require the S-enantiomer, esketamine. Separate ketamine patents, regulatory requirements, and infringement theories would still require analysis.
Does the patent require an oral antidepressant?
Only dependent claims 2, 3, 13, and 14 require adjunctive antidepressant therapy. Claims 1 and 12 do not.
Does claim 12 cover maintenance treatment every four weeks?
No. Claim 12 specifies maintenance administration once per week or once every two weeks. A four-week interval falls outside the literal frequency stated in that claim.
Is an intranasal esketamine product automatically infringing?
No. Infringement depends on whether the product and its directed use satisfy every limitation of an asserted claim, including dose, formulation, indication, induction duration, and administration frequency.
References
- Johnson & Johnson. (2024). Annual report.
- U.S. Food and Drug Administration. (2019). Spravato (esketamine hydrochloride) prescribing information. NDA 211243.
- U.S. Food and Drug Administration. (2020). FDA approves nasal spray to treat depression in adults who have suicidal thoughts or behavior.
- U.S. Patent and Trademark Office. (2022). U.S. Patent No. 11,311,500, methods of treating depression with intranasal esketamine.
- U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations, 44th ed.: Orange Book.
