Details for Patent: 10,722,522

Which drugs does patent 10,722,522 protect, and when does it expire?

Patent 10,722,522 protects BYFAVO and is included in one NDA.

This patent has twenty-one patent family members in sixteen countries.

Summary for Patent: 10,722,522

Title:	Dosing regimen for sedation with CNS 7056 (remimazolam)
Abstract:	The invention relates to a dosing regimen for sedation with the fast-acting benzodiazepine CNS 7056 in combination with an opioid, in particular fentanyl, whereas CNS 7056 is given in a dose of 2 to 20 mg, preferably between 4 and 9 mg and most preferably between 5 and 8 mg.
Inventor(s):	Karin Wilhelm-Ogunbiyi, Keith Borkett, Gary Stuart Tilbrook, Hugh Wiltshire
Assignee:	Paion UK Ltd
Application Number:	US16/457,387
Patent Claim Types: see list of patent claims	Use;

US Patent 10,722,522: Remimazolam Sedation Claims, Patent Scope, Expiration, and Generic Risk

US Patent 10,722,522 protects a specific intravenous remimazolam sedation regimen rather than the remimazolam molecule generally. Its core limitation is a 5 mg intravenous initial dose administered over one minute to sedate an adult. Dependent claims add repeat dosing at intervals of at least two minutes, supplemental doses of approximately 2 to 3 mg, use of the besylate salt, sedation lasting less than 30 minutes, and airway or positive-pressure support.

The patent is directed to Byfavo, whose active ingredient is remimazolam besylate. The claimed regimen closely tracks the FDA-approved procedural-sedation dosing protocol. The patent’s nominal expiration is February 25, 2036, subject to any applicable patent-term adjustment or extension. It is a method-of-use patent and does not, based on the supplied claims, independently protect remimazolam composition, manufacturing, formulation, or every use of the drug.

What drug does US Patent 10,722,522 protect?

The compound identified in the claims is remimazolam, chemically described as:

3-[(4S)-8-bromo-1-methyl-6-(2-pyridinyl)-4H-imidazo[1,2-a][1,4]benzodiazepine-4-yl]propionic acid methyl ester.

The patent also covers a pharmaceutically acceptable salt, with claim 6 specifically identifying the besylate salt. Remimazolam besylate is marketed in the United States as Byfavo by Acacia Pharma, with the product approved for induction and maintenance of procedural sedation in adults undergoing procedures lasting 30 minutes or less. [1]

Item	Details
Brand	Byfavo
Active ingredient	Remimazolam besylate
Drug class	Ultra-short-acting benzodiazepine sedative
FDA dosage form	Intravenous injection
FDA indication	Induction and maintenance of procedural sedation in adults
Core FDA regimen	5 mg initial dose over approximately one minute; supplemental doses may follow
Patent at issue	US 10,722,522
Patent type	Method of treatment or method of use
Nominal expiration	February 25, 2036
Key commercial exposure	Byfavo procedural-sedation sales and US generic entry timing

What are the claims of US Patent 10,722,522?

The independent claim requires every one of the following elements:

1. An adult subject.
2. Sedation of that subject.
3. Intravenous administration.
4. A 5 mg initial dose.
5. Administration of the initial dose over one minute.
6. Remimazolam or a pharmaceutically acceptable salt.

The claim is not a broad claim to administering remimazolam for sedation. It is a regimen claim with precise dose and administration-time limitations.

Claim-by-claim scope analysis

Claim	Added limitation	Practical significance
1	5 mg intravenous initial dose over one minute in an adult	Core method-of-use claim
2	One or more supplemental or top-up doses	Extends the regimen beyond the initial dose
3	Supplemental dose at least two minutes after initial or prior top-up dose	Timing limitation
4	Supplemental dose of approximately 2 to 3 mg	Dose-range limitation
5	Supplemental dose at least two minutes after initial dose	Narrower timing claim
6	Besylate salt	Directly aligns with Byfavo
7	Sedation for less than 30 minutes	Tracks the FDA-approved procedural-sedation population
8	Airway maintenance or positive-pressure ventilation	Adds a clinical-support limitation

Claim 1 has the broadest scope within the patent. Claims 2 through 8 are narrower and require additional facts that must be proven in an infringement case.

How strong is the patent estate for remimazolam?

The patent is commercially important because its independent claim corresponds closely to the approved Byfavo dosing protocol. Its strength is narrower than a composition patent but potentially stronger for an ANDA applicant seeking approval of the same labeled regimen.

Strengths

The patent has several favorable characteristics:

• The claimed dose is specific and clinically identifiable.
• The one-minute intravenous administration period is stated expressly.
• The approved product uses the besylate salt identified in claim 6.
• The supplemental-dose claims correspond to the labeled use of Byfavo.
• The less-than-30-minute limitation in claim 7 closely tracks the approved indication.
• A generic applicant seeking approval for the full labeled procedural-sedation regimen could face a direct method-of-use challenge.

Limitations

The patent also has meaningful limits:

• It does not, on the face of the supplied claims, cover remimazolam as a chemical compound in all uses.
• It does not expressly claim every intravenous dose.
• It does not cover non-sedation uses.
• It may not cover a regimen materially different from the claimed 5 mg initial dose or one-minute administration period.
• Claims 2 through 5 may be avoided if the product label omits supplemental dosing or specifies different timing and dose ranges, subject to induced-infringement and regulatory-disclosure issues.
• Claim 8 requires airway maintenance or positive-pressure ventilation, which may not occur in every procedure.

The patent’s practical value therefore depends on the approved label, the Orange Book use code, the proposed generic label, and the factual pattern of clinical use.

When does US Patent 10,722,522 expire?

The nominal patent expiration date is February 25, 2036. The calculation is based on the patent-family priority framework and the standard 20-year patent term under 35 U.S.C. § 154. The operative date may differ if the patent received patent-term adjustment, patent-term extension, or another statutory modification. [2]

Milestone	Date or status
Earliest reported priority	February 25, 2015
US patent issuance	July 28, 2020
Nominal patent expiration	February 25, 2036
FDA approval of Byfavo	July 2, 2020
Five-year NCE exclusivity endpoint	July 2, 2025, if applicable
Patent protection after NCE exclusivity	Continues to nominally expire in 2036

Patent expiration and FDA exclusivity are separate rights. FDA exclusivity can restrict approval of a competing application before the patent expires, while patent rights can continue after regulatory exclusivity ends.

What is the Orange Book status of remimazolam and Byfavo?

The FDA Orange Book is the primary source for listed patents and use codes associated with approved small-molecule products. Byfavo is a small-molecule drug, so it is subject to the Hatch-Waxman framework rather than the biosimilar pathway. [3]

US Patent 10,722,522 is associated with the clinical use of remimazolam for procedural sedation. Its relevance is primarily as a method-of-use listing. An Orange Book use code can limit the scope of a listed method to the approved indication and may permit a generic applicant to use a section viii “skinny label” to omit a patented indication.

The decisive questions for generic risk are:

• Whether 10,722,522 remains listed for the relevant Byfavo indication.
• Whether the listed use code covers the entire procedural-sedation regimen or only a narrower use.
• Whether additional remimazolam patents are listed for formulation, dosage, or administration.
• Whether the proposed generic label includes the patented dosing instructions.
• Whether the brand owner asserts induced infringement based on the approved label.

An Orange Book listing does not itself establish infringement or patent validity. It determines the regulatory notice and certification framework for an ANDA applicant.

What FDA exclusivity applies to Byfavo?

Byfavo was approved on July 2, 2020, for induction and maintenance of procedural sedation in adults undergoing procedures lasting 30 minutes or less. [1]

Remimazolam was approved as a new molecular entity, making five-year new chemical entity exclusivity the key statutory exclusivity period if FDA granted that status. On that basis, NCE exclusivity would have blocked an ANDA relying on the reference product until July 2, 2025, although a Paragraph IV filing could be submitted after the fourth anniversary under the Hatch-Waxman framework.

The principal FDA protections are distinct:

Protection	Function	Approximate endpoint
NCE exclusivity	Blocks certain abbreviated applications relying on the reference product	July 2, 2025, if applicable
Patent protection	Can block commercial launch unless invalidated, not infringed, licensed, or expired	Nominally February 25, 2036 for US 10,722,522
Orphan exclusivity	Applies only if an orphan designation and approval qualify	Not established by the supplied record
Pediatric exclusivity	Adds six months if FDA requirements are met	Not established by the supplied record

Are there Paragraph IV challenges to US Patent 10,722,522?

A Paragraph IV certification would assert that the patent is invalid, unenforceable, or will not be infringed by the proposed generic product. It would be the expected challenge mechanism for an ANDA applicant seeking approval before February 2036.

The patent presents several potential Paragraph IV issues:

Infringement defenses

A generic applicant could argue that its proposed label does not require:

• A 5 mg initial dose.
• Administration over one minute.
• Supplemental dosing at two-minute intervals.
• A 2 to 3 mg supplemental dose.
• Use of the besylate salt.
• Sedation for procedures lasting less than 30 minutes.

The strength of these defenses would depend heavily on the precise ANDA label and the regulatory instructions for administering the generic product.

Validity defenses

Potential validity challenges could address:

• Obviousness based on prior remimazolam dosing studies.
• Written description or enablement of the specified dosing regimen.
• Anticipation by clinical publications or patent disclosures.
• Claim construction of “5 mg,” “over a period of 1 minute,” “not less than 2 minutes,” and “about 2 mg and 3 mg.”
• Whether the claimed regimen produces a legally significant unexpected result over known benzodiazepine sedation protocols.

The supplied claims do not establish the patent’s prosecution history, prior-art record, or claim amendments. Those materials can materially affect the validity assessment.

No specific Paragraph IV lawsuit or settlement agreement is established by the claims supplied in the request. A definitive litigation conclusion requires the current FDA Orange Book listing, ANDA litigation docket, and patent-family prosecution records.

What generic launch risks exist for Byfavo?

The most likely launch scenarios are:

Scenario	Commercial result
No ANDA challenge	Generic launch delayed until patent expiry or license
Paragraph IV challenge unsuccessful	Launch delayed until patent expiry or settlement date
Patent invalidated or not infringed	Potential launch before 2036, subject to FDA approval
Skinny label accepted	Generic may launch for unpatented uses while omitting the patented regimen
Authorized generic or license	Earlier market entry under negotiated terms
Label redesign	Entry may occur if the proposed regimen avoids the listed method claims

Because claim 1 tracks the labeled initial dose, a full-label generic could face substantial litigation risk. A skinny-label strategy could be more viable if the Orange Book use code can be carved out and the generic label omits the patented method. That strategy is not automatically effective if the remaining label, product materials, or marketing activities encourage use of the patented regimen.

Does remimazolam face biosimilar risk?

No. Remimazolam is a chemically synthesized small molecule, not a biologic. Competitive products would proceed through the ANDA pathway or, in some circumstances, a 505(b)(2) application. The relevant competitive risks are generic substitution, formulation differentiation, licensing, and clinical-label design.

Biosimilar concepts such as interchangeability, reference biologic exclusivity, and the Purple Book do not apply to Byfavo.

What other patents may affect remimazolam competition?

The remimazolam landscape can include several patent categories:

1. Core compound patents. These cover the remimazolam chemical structure or related benzodiazepine derivatives.
2. Salt patents. These may address remimazolam besylate or other pharmaceutically acceptable salts.
3. Formulation patents. These may cover lyophilized injectable compositions, reconstitution, stabilizers, concentration, pH, or container systems.
4. Method-of-use patents. US 10,722,522 falls primarily in this category.
5. Dosing patents. These may cover induction, maintenance, supplemental dosing, or procedural duration.
6. Manufacturing patents. These can cover synthesis, purification, crystallization, salt formation, or impurity control.
7. Regulatory exclusivity. NCE exclusivity can delay ANDA approval even without a blocking patent.

The existence of related patents does not establish that each remains enforceable or listed in the Orange Book. Patent-family members also may have different claims, owners, expiration dates, and terminal disclaimers.

How does US Patent 10,722,522 compare with a composition patent?

Issue	US 10,722,522 method patent	Composition patent
Protected subject	Specific sedation regimen	Chemical compound or composition
Dependence on label	High	Lower
Infringement proof	Requires use of claimed regimen	May arise from making, using, or selling compound
Design-around potential	Relatively meaningful	Usually more limited before expiration
Orange Book relevance	Use-code dependent	Product and active-ingredient dependent
Generic risk	Highest for full-label copy	Potentially broad across indications
Commercial leverage	Strong if label matches claim	Stronger if still unexpired and valid

The value of 10,722,522 is therefore concentrated in the approved dosing protocol. It does not have the same exclusionary reach as an unexpired composition patent covering remimazolam itself.

What patent litigation or settlement issues should investors monitor?

The principal monitoring points are:

• Any Paragraph IV notice involving US 10,722,522.
• A federal action filed within 45 days of notice.
• Changes to the Orange Book use code.
• Patent-term adjustment or patent-term-extension records.
• Additional Byfavo patents listed after approval.
• ANDA applicants seeking a skinny label.
• License or settlement agreements governing generic launch.
• FDA approval of a generic or 505(b)(2) remimazolam product.
• Changes in Byfavo labeling that alter the claimed dose or procedure duration.

A patent settlement could permit entry before February 2036 while preserving the patent’s formal validity. Without a public agreement, the commercial entry date cannot be inferred from the patent expiration date alone.

Key Takeaways

• US Patent 10,722,522 is a regimen-specific method patent for intravenous remimazolam sedation.
• Claim 1 requires a 5 mg initial dose administered over one minute to an adult.
• Dependent claims cover supplemental 2 to 3 mg doses, intervals of at least two minutes, the besylate salt, procedures under 30 minutes, and airway or positive-pressure support.
• The patent closely tracks the FDA-approved Byfavo dosing protocol.
• Its nominal expiration is February 25, 2036, subject to patent-term adjustments or extensions.
• It is not a biosimilar issue; remimazolam is a small molecule subject to Hatch-Waxman competition.
• A full-label ANDA could face meaningful method-of-use infringement risk.
• A skinny-label strategy may reduce risk if the patented use can be cleanly omitted.
• The commercial strength of the patent depends on the current Orange Book listing, use code, prosecution history, and any Paragraph IV litigation or settlement.

FAQs

Can a generic launch before 2036 if it changes the remimazolam dose?

Potentially. A materially different dose may avoid claim 1, but the analysis depends on whether the generic label still instructs or encourages the claimed 5 mg one-minute regimen and whether other Byfavo patents apply.

Does claim 6 cover remimazolam free base?

No. Claim 6 specifically narrows claim 1 to the besylate salt. Claim 1 itself covers the compound or a pharmaceutically acceptable salt, subject to the remaining limitations.

Does US 10,722,522 cover all procedural sedation with remimazolam?

No. The claims require particular dosing and timing limitations. Use outside those limitations may fall outside the patent, although other patents or infringement theories could remain relevant.

Can a 505(b)(2) applicant challenge this patent?

Yes. A 505(b)(2) applicant may address listed patents through the applicable certification process. The risk analysis differs from an ANDA because the proposed product, labeling, and reliance package may differ.

Does FDA approval of a generic prove that US 10,722,522 is invalid?

No. FDA approval and patent validity are separate issues. A generic may be approved with a certification or label strategy that avoids commercial infringement, while the patent remains in force.

References

1. U.S. Food and Drug Administration. (2020). Byfavo (remimazolam besylate) prescribing information.
2. U.S. Patent No. 10,722,522. (2020). Methods of administering remimazolam. United States Patent and Trademark Office.
3. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations, commonly known as the Orange Book.
4. 35 U.S.C. § 154. Patent term.
5. 21 U.S.C. § 355. New drug applications and abbreviated applications.
6. 21 C.F.R. Part 314. Applications for FDA approval to market a new drug.

Drugs Protected by US Patent 10,722,522

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Acacia	BYFAVO	remimazolam besylate	POWDER;INTRAVENOUS	212295-001	Oct 6, 2020		RX	Yes	Yes						USE OF REMIMAZOLAM FOR INDUCTION AND MAINTENANCE OF PROCEDURAL SEDATION IN ADULTS UNDERGOING PROCEDURES LASTING 30 MINUTES OR LESS

Foreign Priority and PCT Information for Patent: 10,722,522

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
	10014366	Nov 8, 2010
	10014784	Nov 19, 2010
	10014819	Nov 22, 2010
	10014972	Nov 25, 2010

International Family Members for US Patent 10,722,522

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2011328497
China	103347519
Denmark	2637662
Eurasian Patent Organization	024926
Eurasian Patent Organization	201390672
European Patent Office	2450039