Details for Patent: 9,889,118

Which drugs does patent 9,889,118 protect, and when does it expire?

Patent 9,889,118 protects BARHEMSYS and is included in one NDA.

This patent has fifty-two patent family members in twenty-six countries.

Summary for Patent: 9,889,118

Title:	Use of amisulpride as an anti-emetic
Abstract:	Amisulpride is used in the therapy of nausea, vomiting or retches. The therapy may utilize a novel injectable formulation, in unit dosage form, comprising less than 50 mg amisulpride.
Inventor(s):	Julian Clive Gilbert, Robert William Gristwood, Nicola Cooper, Gabriel Fox
Assignee:	Acacia Pharma Ltd
Application Number:	US15/374,174
Patent Claim Types: see list of patent claims	Use; Delivery;

United States Patent 9,889,118: Amisulpride Post-Operative Nausea and Vomiting Patent Analysis

United States Patent 9,889,118 protects methods of preventing or treating post-operative nausea and vomiting, or PONV, by administering amisulpride at a dose below 50 mg. The broadest protection is claim 1. The patent is a method-of-use patent, not a general composition patent, and its commercial significance is tied to low-dose injectable amisulpride products such as Barhemsys.

The patent covers human surgical patients, combination treatment with antiemetics, use after anesthetic administration, specified surgeries, multiple administration routes, and the claimed S(-)-amisulpride form. The strongest commercial overlap is with intravenous amisulpride administered perioperatively at doses of 5 mg or 10 mg.

What does United States Patent 9,889,118 protect?

Patent 9,889,118 claims the use of amisulpride for PONV prevention or treatment at a dose of less than 50 mg.

Feature	Scope under Patent 9,889,118
Active ingredient	Amisulpride
Primary indication	Prevention and/or treatment of PONV
Dose	Less than 50 mg under claim 1; 1 mg to 35 mg under claim 11
Patient	A subject undergoing surgery; claim 5 narrows this to humans
Administration context	Surgical procedure, often after anesthetic administration
Combination therapy	Opiates, morphine, another antiemetic, a 5-HT3 antagonist, ondansetron, or dexamethasone
Surgical procedures	Eye or ear procedures, laparoscopic cholecystectomy, hysterectomy, breast surgery, abdominal surgery, and gynecological surgery
Routes	Intravenous, intramuscular, subcutaneous, oral, sublingual, intranasal, topical, transdermal, and rectal
Chemical form	Amisulpride or an acceptable pharmaceutical salt
Stereochemical limitation	S(-)-amisulpride under claim 20

The patent does not claim every use of amisulpride. It does not, on its face, cover amisulpride for schizophrenia, psychosis, depression, or other non-PONV indications. It also does not claim an unrestricted amisulpride composition independent of its use in PONV.

How do the independent and dependent claims differ?

Claim 1 is the principal infringement claim. A method generally falls within claim 1 if it includes:

1. A surgical subject in need of PONV prevention or treatment;
2. Administration of amisulpride; and
3. Administration at a dose below 50 mg.

The claim uses “prevention and/or treatment,” giving it both prophylactic and therapeutic reach. A product administered before vomiting occurs may satisfy the prevention component. Administration after symptoms develop may satisfy the treatment component.

Claims 2 through 20 add narrower limitations. They do not replace claim 1; they depend on and incorporate all limitations of claim 1.

Key dependent-claim groups

Claims 2 through 4 cover treatment where the patient also receives an emetogenic agent, particularly an opiate or morphine. These claims are relevant to postoperative protocols involving opioid analgesia.

Claims 7 through 10 cover combination antiemetic protocols. Claim 8 covers a 5-HT3 antagonist, claim 9 identifies ondansetron, and claim 10 identifies dexamethasone.

Claim 11 narrows the dose to 1 mg through 35 mg. This range captures the principal clinical dosing territory for Barhemsys and excludes doses below 1 mg or above 35 mg, while claim 1 remains available for doses from above 35 mg to below 50 mg.

Claims 12 through 13 narrow the surgical setting. Claim 12 requires prior anesthetic administration. Claim 13 identifies particular surgeries but does not necessarily limit the independent claim to those procedures because claim 13 is dependent.

Claims 14 through 19 cover numerous delivery routes. Claims 14 and 15 concern injectable and oral administration. Claims 16 through 19 extend to sublingual, intranasal, topical, transdermal, and rectal delivery.

Claim 20 covers S(-)-amisulpride. Its practical importance depends on whether a commercial product contains that stereochemical form and whether the form is materially distinct from the administered amisulpride identified in the broader claims.

What is the likely claim scope for Barhemsys?

Barhemsys is an intravenous amisulpride product approved by the FDA for the prevention and treatment of PONV in adults. Its labeled use is closely aligned with the core elements of claim 1 and claim 11.

Barhemsys-related feature	Relationship to Patent 9,889,118
Intravenous amisulpride	Falls within claim 14
PONV prevention	Falls within claim 1
PONV treatment	Falls within claim 1
Low-milligram dosing	Falls within claim 1 and potentially claim 11
Adult surgical patients	Consistent with claims 1 and 5
Use after anesthesia	Falls within claim 12 where the factual requirements are met
Combination with other antiemetics	Falls within claims 7 through 10 when applicable

The patent is therefore directed at the therapeutic use that distinguishes low-dose amisulpride from its earlier psychiatric use. The commercial product’s formulation, manufacturing process, and presentation may be protected by separate patents or regulatory exclusivity, but Patent 9,889,118 itself principally protects the PONV method.

When does United States Patent 9,889,118 expire?

Patent 9,889,118 issued on February 20, 2018. Public patent-family and company disclosures identify February 2033 as the expected expiration period for the principal PONV patent family. The precise enforceable expiration date depends on the patent-term calculation, including any patent-term adjustment recorded by the USPTO.

Event	Date or period
U.S. patent issuance	February 20, 2018
Expected patent-term end	February 2033
FDA approval of Barhemsys	February 26, 2020
Three-year clinical-investigation exclusivity	Approximately through February 2023
Commercial generic-risk window	Primarily after expiration or settlement of the relevant listed patents

The patent term does not run for 20 years from the issue date. It is generally calculated from the earliest effective nonprovisional or international filing date, subject to adjustments and terminal disclaimers.

What is the Orange Book status of amisulpride and Barhemsys?

Barhemsys is marketed under FDA NDA 212281. FDA’s Orange Book is the primary source for listed patents and certifications associated with approved drug products.

Patent 9,889,118 has been identified in public company and patent disclosures as an Orange Book-listed patent associated with Barhemsys. Its listing is significant because an ANDA applicant seeking approval for a generic version may need to address the patent through a Paragraph IV certification if the applicant seeks approval before the listed patent expires.

An Orange Book listing does not establish that every claim is valid or infringed. It creates a regulatory patent-certification mechanism and may trigger statutory litigation and approval-delay consequences under the Hatch-Waxman Act.

Are there Paragraph IV challenges to Patent 9,889,118?

A Paragraph IV certification alleges that a listed patent is invalid, unenforceable, or will not be infringed by the proposed generic product. A certification can result in patent litigation under 21 U.S.C. § 355(j).

Publicly available company materials have identified the 2033 Barhemsys patent estate as a protection barrier. No widely reported final court decision has invalidated Patent 9,889,118. The business risk from a Paragraph IV challenge would depend on:

• Whether the ANDA product is labeled for PONV prevention or treatment;
• Whether the proposed dose is below 50 mg;
• Whether the ANDA label includes intravenous administration;
• Whether the applicant uses a carve-out under section viii;
• Whether the patent is listed for the relevant NDA;
• Whether the patent holder sues within the statutory period;
• Whether the parties settle before trial.

A generic applicant could attempt to remove the patented PONV indication from its label. That strategy would face practical limits because low-dose intravenous amisulpride has limited commercial value outside the perioperative antiemetic market.

How strong is the patent estate for low-dose amisulpride?

Patent 9,889,118 is commercially strong against a conventional generic of Barhemsys because the claim tracks the product’s central clinical use. The patent is less comprehensive against nonstandard products or alternative commercial strategies.

Strengths

The patent has several favorable characteristics:

• Claim 1 uses a broad “less than 50 mg” threshold.
• The claim covers both prevention and treatment.
• The claim applies to surgical subjects generally.
• Dependent claims cover common perioperative combinations.
• The dose range in claim 11 captures clinically relevant low-dose administration.
• The claims cover multiple routes, including intravenous administration.
• The patent protects use rather than depending solely on a specific formulation.

Potential vulnerabilities

The broad claim may face challenges based on prior art involving:

• Earlier use of amisulpride as an antiemetic;
• Known dopamine D2 or D3 receptor antagonism;
• Other perioperative antiemetic regimens;
• Clinical or experimental disclosures involving amisulpride doses below 50 mg;
• Obviousness arguments based on selecting a lower dose from known amisulpride dosing;
• Written-description or enablement arguments for routes not demonstrated in the specification.

The claim’s scope also depends on how a court interprets “administering amisulpride at a dose of less than 50 mg.” Issues may include whether the limitation refers to a single dose, total perioperative dose, or dose per administration; whether a salt is measured by amisulpride-equivalent weight; and whether the treating physician, hospital, manufacturer, or patient performs the claimed method.

What generic launch scenarios exist?

Scenario 1: Launch after patent expiration

This is the lowest litigation-risk path. A generic applicant could obtain approval and launch after the relevant Orange Book patents expire, assuming no separate unexpired formulation, process, or use patents block commercial launch.

Scenario 2: Paragraph IV challenge

The applicant could challenge validity or infringement and launch at risk after obtaining approval or prevailing in litigation. The principal arguments would likely focus on obviousness, written description, enablement, and claim construction.

Scenario 3: Section viii label carve-out

An ANDA applicant could seek approval without the patented PONV indication if FDA permits an adequate labeling carve-out. This strategy is difficult where the patented indication represents the product’s primary or only commercial use.

Scenario 4: Authorized generic or settlement launch

The patent holder could license or authorize a competing generic before expiration. Any settlement would require antitrust and Hatch-Waxman analysis, particularly if it includes delayed entry, supply terms, or payments.

What other patents may protect Barhemsys?

Patent 9,889,118 should be evaluated as one component of a broader patent estate. Public disclosures have associated additional U.S. patents with low-dose amisulpride and Barhemsys, including later patents directed to related PONV methods, formulations, dosing, or administration approaches.

The relevant diligence categories are:

Patent category	Commercial function
PONV method patents	Protect the clinical indication
Dose-regimen patents	Protect specific dose ranges or timing
Formulation patents	Protect injectable stability, excipients, concentration, or pH
Device or presentation patents	Protect vial, syringe, or administration format
Manufacturing patents	Protect synthesis, purification, polymorph, or salt production
Regulatory exclusivity	Delays certain FDA approvals independently of patent validity

A freedom-to-operate review should examine every Orange Book-listed patent for NDA 212281 and every unlisted patent that could create supply-chain or manufacturing exposure.

Does Patent 9,889,118 create biosimilar risk?

No. Biosimilar rules apply to biologic products under the Public Health Service Act. Amisulpride is a small-molecule chemical drug. Competitive entry would occur through the ANDA pathway, not the abbreviated biologics license application pathway.

The relevant competitive risks are generic substitution, Paragraph IV litigation, authorized-generic entry, and off-label or compounded alternatives.

What licensing and ownership issues affect the patent?

The patent was developed within the Acacia Pharma low-dose amisulpride program. Commercial ownership and exploitation rights have been associated with Acacia Pharma and, following Acacia’s corporate transactions, its successor or acquiring commercial interests.

A transaction review should distinguish:

• Patent ownership recorded at the USPTO;
• NDA ownership recorded by FDA;
• Commercial marketing rights;
• Manufacturing rights;
• Territorial licenses;
• Sublicenses;
• Patent-prosecution control;
• Litigation-control rights.

A license or acquisition of marketing rights does not necessarily transfer ownership of the patent. The USPTO assignment database and FDA NDA records should be reconciled before relying on a counterparty’s representations.

How does Patent 9,889,118 compare with a formulation patent?

Patent 9,889,118 protects what the product is used to do. A formulation patent protects how the product is physically made or delivered.

A competitor may avoid a formulation patent by changing excipients or concentration. It may have more difficulty avoiding Patent 9,889,118 if its product remains injectable amisulpride administered below 50 mg for PONV. Conversely, a competitor that avoids the patented indication may reduce infringement risk but also remove the product’s principal commercial use.

What litigation and settlement risks should investors monitor?

The main events to monitor are:

1. FDA Orange Book changes for NDA 212281;
2. ANDA filings and Paragraph IV notices;
3. Federal district court complaints under Hatch-Waxman;
4. Patent-term-adjustment records;
5. USPTO post-grant proceedings;
6. Patent assignments and exclusive licenses;
7. Generic approvals with section viii labeling;
8. Settlement agreements and authorized-generic arrangements;
9. FDA labeling changes for Barhemsys;
10. Separate litigation involving formulation or manufacturing patents.

No biosimilar litigation pathway applies. The commercial dispute is likely to center on generic labeling, claim construction, obviousness, and the enforceability of the 2033 patent estate.

Key Takeaways

• Patent 9,889,118 is a low-dose amisulpride PONV method patent.
• Claim 1 is broad and covers administration below 50 mg to a surgical subject.
• Claim 11 specifically covers the 1 mg-to-35 mg range.
• Intravenous administration is expressly covered by claim 14.
• Combination use with ondansetron, dexamethasone, opiates, and morphine is covered by dependent claims.
• The patent is closely aligned with the clinical use of Barhemsys.
• The expected expiration period is February 2033, subject to the USPTO’s final term calculation.
• Generic applicants would likely use Paragraph IV or a section viii label strategy.
• Amisulpride is a small molecule, so biosimilar litigation is not relevant.
• The patent should be analyzed with later PONV, formulation, manufacturing, and Orange Book-listed patents.

FAQs About United States Patent 9,889,118

Can a hospital infringe Patent 9,889,118 by using generic amisulpride?

Yes, potentially. A hospital-administered product could practice the claimed method if it uses amisulpride below 50 mg for PONV in a surgical patient. Liability would depend on the statutory elements, the actor’s conduct, available defenses, and the patent’s enforceability.

Does a dose of exactly 50 mg fall within claim 1?

No. Claim 1 requires a dose of “less than 50 mg.” Exactly 50 mg is outside that literal numerical limitation, although other claims, patents, or infringement theories may require separate analysis.

Does Patent 9,889,118 cover amisulpride tablets for schizophrenia?

No, not based on the quoted claims. The claims require a surgical subject and PONV prevention or treatment. Ordinary psychiatric use is outside the stated claim scope.

Can a generic omit the PONV indication from its FDA label?

Potentially, through a section viii strategy, if FDA accepts the carve-out and the remaining labeling does not induce infringement of the patented method. The commercial value of such a generic may be limited if PONV is the principal approved use.

Is S(-)-amisulpride required for every claim?

No. S(-)-amisulpride is required only by claim 20. Claims 1 through 19 do not contain that stereochemical limitation based on the claim text provided.

References

1. Acacia Pharma plc. (2021). Annual report and accounts.
2. Acacia Pharma plc. (2022). Annual report and accounts.
3. U.S. Food and Drug Administration. (2020). Barhemsys (amisulpride) injection: Prescribing information, NDA 212281.
4. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book.
5. U.S. Patent and Trademark Office. (2018). United States Patent No. 9,889,118, methods for prevention and treatment of postoperative nausea and vomiting.
6. Federal Food, Drug, and Cosmetic Act, 21 U.S.C. § 355.
7. 35 U.S.C. §§ 154, 271, and 282.

Drugs Protected by US Patent 9,889,118

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	209510-001	Feb 26, 2020		RX	Yes	Yes						PREVENTION 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
Lxo Ireland	BARHEMSYS	amisulpride	SOLUTION;INTRAVENOUS	209510-002	Sep 1, 2020		RX	Yes	Yes						PREVENTION OF POST-OPERATIVE NAUSEA AND VOMITING

Foreign Priority and PCT Information for Patent: 9,889,118

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
United Kingdom	1004020.2	Mar 11, 2010

International Family Members for US Patent 9,889,118

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2011225898
Brazil	112012022746
Canada	2792392
China	102892407
Cyprus	1115485