Details for Patent: 11,357,753

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Which drugs does patent 11,357,753 protect, and when does it expire?

Patent 11,357,753 protects BARHEMSYS and is included in one NDA.

This patent has twenty-two patent family members in fourteen countries.

Summary for Patent: 11,357,753

Title:	Rescue treatment of post operative nausea and vomiting
Abstract:	Amisulpride is useful in the treatment of postoperative nausea and/or vomiting in a patient, wherein the patient has already been administered a prophylaxis drug for postoperative nausea and/or vomiting, and wherein the dose of amisulpride is 7.5 to 15 mg.
Inventor(s):	Julian Clive Gilbert, Robert William Gristwood, Gabriel Fox
Assignee:	Acacia Pharma Ltd
Application Number:	US16/485,008
Patent Claim Types: see list of patent claims	Use;

US Patent 11,357,753: Amisulpride for Rescue Treatment of Postoperative Nausea and Vomiting

US Patent No. 11,357,753 protects a specific clinical use of amisulpride: administering a 10-mg dose, generally intravenously, to a surgical patient who received a non-amisulpride prophylactic antiemetic and subsequently developed postoperative nausea and/or vomiting (PONV). The patent does not claim amisulpride as a chemical compound, all uses of amisulpride, or every formulation of amisulpride.

The commercial relevance is substantial because the claimed sequence tracks the labeled use of intravenous amisulpride, marketed in the United States as Barhemsys by Acacia Pharma. The strongest infringement theory would involve a 10-mg IV rescue dose administered after prophylaxis failure. The principal validity and enforcement issues concern claim construction, written description, obviousness, clinical protocol evidence, and whether a generic product label would induce the claimed treatment sequence.

What does US Patent 11,357,753 claim?

The patent claims a treatment method with multiple cumulative limitations. Every limitation of an asserted claim must be met for literal infringement.

Claim	Protected subject matter	Practical scope
1	Treating PONV with 10 mg amisulpride after prophylaxis, surgery, and onset of PONV	Core rescue-treatment claim
2	Claim 1 where the prophylactic drug is not a D2 antagonist	Narrows prophylaxis to non-D2 therapy
3	Claim 1 where prophylaxis is a 5-HT3 antagonist, corticosteroid, H1 antihistamine, anticholinergic, H2 antagonist, or NK1 antagonist	Covers common PONV prophylaxis classes
4	Claim 1 with another antiemetic administered sequentially or simultaneously	Covers combination rescue treatment
5	Claim 4 where the second antiemetic is a 5-HT3 antagonist, NK1 antagonist, or steroid	Narrows the combination
6	Claim 5 identifying dexamethasone, ondansetron, granisetron, palonosetron, aprepitant, netupitant, or rolapitant	Drug-specific combination coverage
7	Claim 1 using amisulpride substantially as a racemate	Covers the racemic drug product
8	Claim 1 where amisulpride is administered intravenously	Commercially important IV-use claim

The independent claim is claim 1. Claims 2 through 8 depend on claim 1 and add restrictions. Claim 8 is particularly important because the approved U.S. product is an intravenous amisulpride formulation.

What clinical sequence must occur for claim 1 to apply?

Claim 1 requires the following sequence:

1. The patient receives a prophylaxis drug for PONV.
2. The patient undergoes a surgical procedure.
3. The patient experiences PONV.
4. The prophylaxis drug is not amisulpride.
5. Amisulpride is then administered.
6. The amisulpride dose is 10 mg.
7. The administration treats postoperative nausea and/or vomiting.

The claim is narrower than a general claim covering amisulpride for nausea. It is directed to rescue treatment after prophylaxis failure. The order of events matters. Administration of amisulpride before surgery, or as prophylaxis rather than rescue treatment, would not naturally satisfy the express sequence in claim 1.

The claim also requires that the patient experienced PONV before amisulpride was administered. A product used solely to prevent PONV would fall outside the literal language of claim 1, although other patents or infringement theories could remain relevant.

How do the dependent claims expand the patent’s commercial coverage?

Claims 2 and 3 focus on the prophylactic regimen. Claim 3 is commercially broad because it reaches several standard PONV prophylaxis classes, including ondansetron, dexamethasone, and NK1 antagonists.

Claim 4 reaches combination therapy. It does not require simultaneous administration. Sequential administration is sufficient. This language can cover a rescue protocol in which amisulpride is given after one or more additional antiemetics, provided the other claim elements are met.

Claim 6 provides named-drug coverage. A protocol using 10 mg amisulpride after prophylaxis with ondansetron or dexamethasone, followed by or combined with another listed antiemetic, is a direct target of the claim set.

Claim 7 addresses the chemical form. Amisulpride is generally used clinically as a racemic product. The phrase "substantially in the form of a racemate" is intended to prevent an argument that the claim covers only an exact, analytically pure 50:50 mixture.

Claim 8 targets IV administration. It is narrower than claim 1 but aligns closely with the approved Barhemsys route of administration.

What does the patent not cover?

US 11,357,753 does not, on its face, claim:

• The amisulpride molecule itself.
• Oral amisulpride products for schizophrenia or other psychiatric indications.
• Any dose other than 10 mg under claim 1.
• Amisulpride administered before PONV develops.
• Amisulpride used only as a prophylactic agent.
• Treatment of nausea unrelated to surgery.
• Treatment of chemotherapy-induced nausea and vomiting.
• Every formulation containing amisulpride.
• Manufacturing processes for amisulpride or an injectable product.
• A product-by-process claim.
• A monopoly over D2-antagonist combinations generally.

A competing product could therefore avoid literal infringement if it is promoted only for a non-PONV use, uses a different dose, is administered before the patient experiences PONV, or does not carry instructions that encourage the claimed sequence. Those strategies would not automatically eliminate infringement risk under induced-infringement or contributory-infringement theories.

What patent protects Barhemsys and intravenous amisulpride?

The 11,357,753 patent is one part of the U.S. patent estate associated with intravenous amisulpride and Barhemsys. The estate is use-focused rather than dependent on a new chemical entity patent.

Protection category	Relevance to Barhemsys
Active ingredient	Amisulpride was previously known and marketed outside the United States
Clinical use	PONV rescue treatment is the central U.S. commercial indication
Dose	The patent specifically centers on 10 mg
Route	IV administration is separately claimed
Treatment sequence	Rescue after prophylaxis failure is a core limitation
Combination therapy	Claims cover specified antiemetic combinations
Formulation	Separate formulation patents, if listed or granted, must be analyzed independently
Manufacturing	Process protection is not provided by the claims quoted here

Because amisulpride was known before the U.S. approval of Barhemsys, the commercial exclusivity strategy relies heavily on method-of-use claims, regulatory exclusivity, and possible formulation or manufacturing patents.

What is the patent expiration date for US 11,357,753?

The patent’s issue date was June 7, 2022. Patent expiration is not calculated from the issue date. A U.S. utility patent ordinarily expires 20 years from the earliest effective nonprovisional or PCT filing date, subject to patent-term adjustment, patent-term extension, terminal disclaimers, and other statutory adjustments.[1]

For the relevant amisulpride PONV patent family, the effective term is expected to extend into the mid-2030s rather than ending in 2022. The issued patent itself does not create a new 20-year term. Any continuation patent in the same family generally shares the parent application’s terminal expiration date unless a separate term adjustment applies.

A definitive expiration analysis must account for:

• The earliest effective U.S. or PCT filing date.
• Patent-term adjustment shown on the issued patent.
• Any terminal disclaimer.
• Patent-term extension under 35 U.S.C. § 156, if granted.
• Whether the patent is listed in the FDA Orange Book and for which use code.

The statutory patent term is distinct from FDA regulatory exclusivity. Patent protection can continue after regulatory exclusivity ends.

What is the Orange Book status of US 11,357,753?

A method-of-use patent can be listed in the Orange Book when it claims an approved use of an approved drug product. The relevant question is not simply whether the patent covers amisulpride. The patent must be linked to the approved labeling through an FDA use code.[2]

For Barhemsys, the likely Orange Book relevance of US 11,357,753 is the approved use of intravenous amisulpride for treatment of PONV, particularly in patients who have received prophylaxis and continue to experience symptoms. The listing would expose an ANDA applicant to a Paragraph IV certification if the applicant seeks approval before patent expiry and does not accept a carve-out of the patented use.

An ANDA applicant could pursue one of three principal paths:

Generic strategy	Effect
Paragraph III certification	Approval deferred until the patent expires
Paragraph IV certification	Applicant asserts invalidity, unenforceability, or noninfringement
Section viii carve-out	Applicant omits the patented PONV use from labeling, if FDA accepts the carve-out

A section viii strategy is difficult where the patented method substantially overlaps the only commercially meaningful use of the product. It is more viable where the applicant can market amisulpride for an unpatented indication or where the proposed label omits the rescue sequence.

When does amisulpride lose exclusivity?

Regulatory and patent exclusivity must be separated.

FDA regulatory exclusivity

FDA approved Barhemsys in February 2020 for prevention and treatment of PONV in adults.[3] Because amisulpride had prior clinical and commercial history outside the United States, the product was not positioned as a conventional U.S. new chemical entity with five years of NCE exclusivity. The approval instead relied on clinical data supporting a new use and new dosage form.

The relevant regulatory protection was therefore shorter than a new chemical entity term and did not itself prevent all future amisulpride approvals. Regulatory exclusivity may have expired before the key method-of-use patents.

Patent exclusivity

The patent estate can continue after FDA exclusivity ends. US 11,357,753 is a use patent, and its commercial value depends on whether:

• The patent remains unexpired.
• The use is listed in the Orange Book.
• The generic applicant must address the patent.
• The generic label encourages the patented PONV treatment.
• The claims survive validity and infringement challenges.

The practical loss-of-exclusivity date is therefore the earliest date on which a competing product can obtain approval and lawfully market without infringing an enforceable listed patent.

How strong are the claims against a generic applicant?

The strongest claim combination is claim 8 read with claim 3:

• IV administration.
• 10 mg amisulpride.
• PONV after surgery.
• Prior prophylaxis.
• Prophylaxis with a listed non-am amisulpride antiemetic.
• Rescue treatment after symptoms occur.

This combination closely tracks a hospital protocol. If a generic label instructs clinicians to administer 10 mg IV amisulpride for PONV after prophylaxis failure, the branded patent holder would have a substantial induced-infringement argument under 35 U.S.C. § 271(b).[4]

The patent’s principal vulnerabilities are different.

Obviousness

An ANDA challenger could argue that prior art disclosed:

• Amisulpride’s antiemetic activity.
• D2-antagonist treatment of nausea.
• IV antiemetic rescue therapy.
• Standard PONV prophylaxis and rescue protocols.
• A 10-mg dose or a clinically adjacent dose range.

The patent holder would respond that the claimed clinical setting, dose, sequence, and observed efficacy were not predictable from the prior art, particularly if the clinical data showed efficacy after prophylaxis failure.

Written description and enablement

The claims cover multiple prophylaxis classes and combinations. A challenger could argue that the specification did not adequately support the full breadth of the listed regimens, especially if the examples used only a subset of prophylactic drugs.

Claim construction

Terms likely to generate disputes include:

• "prophylaxis drug for PONV"
• "experienced PONV"
• "treating"
• "substantially in the form of a racemate"
• "another anti-emetic"
• "sequentially"

The claim does not specify a fixed time interval between prophylaxis and rescue treatment. That omission could broaden clinical coverage but create litigation over how remote the two administrations may be.

Dose limitation

The express 10-mg limitation can protect against a broad anticipation challenge, but it also creates a design-around route. A product labeled only for a different dose may avoid literal infringement, although off-label use and physician-directed administration can create separate enforcement issues.

What Paragraph IV risks exist?

A generic filing directed to IV amisulpride for PONV could face the following risks:

Risk	Assessment
Listed use patent	High if US 11,357,753 is listed for the proposed use
Induced infringement	High if the label describes 10-mg rescue treatment after prophylaxis
Direct infringement	Depends on actual physician administration
Invalidity challenge	Centered on obviousness, written description, and enablement
Section viii carve-out	Potentially viable only if the patented PONV use can be omitted
Launch at risk	Possible after litigation milestones, but exposed to damages and injunction risk
Settlement	Commercially possible if patent litigation is filed, but no settlement should be inferred without a public agreement

A Paragraph IV notice would ordinarily create a 45-day period for the patent owner to bring suit, which can trigger a 30-month stay of FDA approval under the Hatch-Waxman framework, subject to statutory exceptions.[5]

Which companies are likely to challenge the patent estate?

The principal challengers would be companies with injectable antiemetic manufacturing and hospital distribution capabilities. Relevant categories include:

• Generic injectable manufacturers.
• Specialty hospital-product companies.
• Contract manufacturers seeking to commercialize an ANDA.
• Companies with existing ondansetron, granisetron, or other antiemetic sales infrastructure.

The key commercial constraint is not only patent expiry. A challenger must also establish sterile injectable manufacturing, obtain FDA approval, secure hospital formulary placement, and demonstrate reliable supply. Injectable products carry higher manufacturing and recall risk than many oral generics.

No final invalidity judgment, injunction, or settlement affecting US 11,357,753 is established by the patent claims supplied here. A litigation conclusion should not be inferred from the existence of an Orange Book listing or an ANDA challenge.

How does US 11,357,753 compare with ordinary generic drug patents?

US 11,357,753 differs from a conventional compound or formulation patent in four ways:

1. It protects conduct, not the molecule itself.
2. It depends on the patient’s treatment history.
3. It is closely tied to FDA-approved labeling.
4. Its value can be reduced by a successful labeling carve-out.

A compound patent can block almost every product containing the active ingredient. A method-of-use patent must prove that the accused product encourages or results in the claimed clinical use. That makes claim 11,357,753 narrower in theory but commercially powerful when the patented use is the principal labeled indication.

What geographic coverage does the patent provide?

US 11,357,753 provides protection only under U.S. patent law. It does not directly block commercialization in Canada, Europe, Japan, or other jurisdictions.

International protection depends on corresponding national patents in the same priority family. Foreign claims may differ in:

• Dose.
• Route of administration.
• PONV treatment sequence.
• Prophylaxis requirements.
• Combination therapy.
• Patent term.
• Regulatory linkage.

A U.S. FTO conclusion cannot be extended to foreign markets without reviewing the national family members and local regulatory rules.

What manufacturing and formulation barriers remain?

The quoted claims do not independently protect a specific vial, excipient system, concentration, container, or manufacturing process. A competing manufacturer could still face separate IP barriers involving:

• Injectable stability.
• Sterile filtration and aseptic processing.
• Reconstitution requirements.
• Container-closure systems.
• Shelf life.
• Impurity control.
• Dose uniformity.
• Formulation patents.
• Manufacturing know-how.

The absence of a formulation limitation in claim 1 does not establish that the broader Barhemsys estate lacks formulation or process patents. Those rights must be reviewed separately from US 11,357,753 and from the Orange Book listing.

What is the commercial exposure from this patent?

Barhemsys has its highest exposure in the hospital PONV market, where the labeled 10-mg IV rescue protocol maps directly onto claim 8. The patent is less relevant to oral amisulpride, psychiatric use, nonoperative nausea, and products marketed without the PONV indication.

The commercial risk profile is:

Scenario	Commercial effect
Patent survives and remains listed	Delays or restricts labeled generic entry
Generic accepts a Paragraph III position	Entry waits for patent expiry
Generic wins Paragraph IV litigation	Earlier entry becomes possible
FDA accepts a section viii carve-out	Generic may enter for noncovered uses
Generic launches at risk	Potential damages, injunction, and launch disruption
Hospital off-label use continues	Brand enforcement becomes more fact-intensive

Key Takeaways

• US 11,357,753 is a method-of-use patent, not a compound patent.
• Its core protection is 10 mg amisulpride for rescue treatment of PONV after surgery and after non-am-isulpride prophylaxis.
• Claim 8 is commercially important because it specifically covers IV administration.
• Claims 3 and 6 capture common regimens involving ondansetron, dexamethasone, NK1 antagonists, and other antiemetics.
• The patent does not cover oral amisulpride generally or every use of the amisulpride molecule.
• A generic label that instructs use of 10 mg IV amisulpride after prophylaxis failure presents the highest induced-infringement risk.
• The principal validity issues are obviousness, written description, enablement, and construction of the treatment sequence.
• FDA regulatory exclusivity and patent exclusivity are separate. The patent may remain commercially relevant after FDA exclusivity ends.
• Generic entry depends on Orange Book listing, Paragraph IV litigation, possible section viii carve-outs, and the enforceability of related formulation or process patents.
• The patent’s U.S. rights do not determine freedom to operate in foreign markets.

Frequently Asked Questions

Does US 11,357,753 cover oral amisulpride?

No. The quoted claims focus on treatment of PONV with a 10-mg dose, and claim 8 specifically requires IV administration. Oral amisulpride for psychiatric indications is outside the express scope of these claims.

Can a generic avoid the patent by using 5 mg or 20 mg?

A different dose may avoid literal infringement of claim 1, which expressly requires 10 mg. The overall risk would still depend on other patents, the generic label, actual use, and any doctrine-of-equivalents argument.

Does prophylaxis with ondansetron create infringement risk?

Yes, if the patient undergoes surgery, develops PONV, and then receives 10 mg amisulpride under the claimed rescue sequence. Ondansetron is expressly identified in claims 3 and 6.

Is a generic liable if physicians use it off label?

Potentially, but liability depends on the product’s labeling, promotional conduct, intended uses, and the evidence linking the manufacturer to the infringing use. Physician conduct alone does not resolve induced-infringement questions.

Does the patent block amisulpride for chemotherapy-induced nausea?

Not under the claims supplied. The claims require postoperative nausea and/or vomiting associated with a surgical procedure. Chemotherapy-induced nausea is a different clinical setting.

References

1. United States Patent and Trademark Office. (2022). US Patent No. 11,357,753: Amisulpride for the treatment of postoperative nausea and vomiting.
2. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations.
3. U.S. Food and Drug Administration. (2020). FDA approves Barhemsys for prevention and treatment of postoperative nausea and vomiting.
4. United States Code, 35 U.S.C. § 271.
5. United States Code, 21 U.S.C. § 355(j).

Drugs Protected by US Patent 11,357,753

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Lxo Ireland	BARHEMSYS	amisulpride	SOLUTION;INTRAVENOUS	209510-001	Feb 26, 2020		RX	Yes	Yes						TREATMENT OF POST-OPERATIVE NAUSEA AND VOMITING
Lxo Ireland	BARHEMSYS	amisulpride	SOLUTION;INTRAVENOUS	209510-002	Sep 1, 2020		RX	Yes	Yes						TREATMENT OF POST-OPERATIVE NAUSEA AND VOMITING

Foreign Priority and PCT Information for Patent: 11,357,753

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
United Kingdom	1702250	Feb 10, 2017

PCT Information
PCT Filed	February 09, 2018	PCT Application Number:	PCT/GB2018/050374
PCT Publication Date:	August 16, 2018	PCT Publication Number:	WO2018/146490

International Family Members for US Patent 11,357,753

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2018218310
Australia	2024203155
Brazil	112019016565
Canada	3052535
China	110603036
China	122351229
Eurasian Patent Organization	201991667