XACDURO (COPACKAGED) Drug Patent Profile

When do Xacduro (copackaged) patents expire, and what generic alternatives are available?

Xacduro (copackaged) is a drug marketed by Entasis Therap and is included in one NDA. There are four patents protecting this drug.

This drug has eighty patent family members in forty-three countries.

The generic ingredient in XACDURO (COPACKAGED) is durlobactam sodium; durlobactam sodium; sulbactam sodium. One supplier is listed for this compound. Additional details are available on the durlobactam sodium; durlobactam sodium; sulbactam sodium profile page.

DrugPatentWatch^® Generic Entry Outlook for Xacduro (copackaged)

Xacduro (copackaged) will be eligible for patent challenges on May 23, 2027. This date may extended up to six months if a pediatric exclusivity extension is applied to the drug's patents.

By analyzing the patents and regulatory protections it appears that the earliest date for generic entry will be May 23, 2033. This may change due to patent challenges or generic licensing.

There has been one patent litigation case involving the patents protecting this drug, indicating strong interest in generic launch. Recent data indicate that 63% of patent challenges are decided in favor of the generic patent challenger and that 54% of successful patent challengers promptly launch generic drugs.

Indicators of Generic Entry

Summary for XACDURO (COPACKAGED)

International Patents:	80
US Patents:	4
Applicants:	1
NDAs:	1
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for XACDURO (COPACKAGED)

US Patents and Regulatory Information for XACDURO (COPACKAGED)

XACDURO (COPACKAGED) is protected by four US patents and two FDA Regulatory Exclusivities.

This potential generic entry date is based on GENERATING ANTIBIOTIC INCENTIVES NOW.

Generics may enter earlier, or later, based on new patent filings, patent extensions, patent invalidation, early generic licensing, generic entry preferences, and other factors.

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Entasis Therap	XACDURO (COPACKAGED)	durlobactam sodium; durlobactam sodium; sulbactam sodium	POWDER;INTRAVENOUS	216974-001	May 23, 2023		RX	Yes	Yes			Y
Entasis Therap	XACDURO (COPACKAGED)	durlobactam sodium; durlobactam sodium; sulbactam sodium	POWDER;INTRAVENOUS	216974-001	May 23, 2023		RX	Yes	Yes				Y
Entasis Therap	XACDURO (COPACKAGED)	durlobactam sodium; durlobactam sodium; sulbactam sodium	POWDER;INTRAVENOUS	216974-001	May 23, 2023		RX	Yes	Yes			Y

International Patents for XACDURO (COPACKAGED)

When does loss-of-exclusivity occur for XACDURO (COPACKAGED)?

Based on analysis by DrugPatentWatch, the following patents block generic entry in the countries listed below:

Argentina

Australia

Brazil

Canada

Chile

China

Colombia

Costa Rica

Croatia

Cyprus

Denmark

Dominican Republic

European Patent Office

Hong Kong

Hungary

India

Israel

Japan

Lithuania

Malaysia

Mexico

Montenegro

Morocco

New Zealand

Norway

Peru

Philippines

Poland

Portugal

Russian Federation

San Marino

Serbia

Singapore

Slovenia

South Korea

Spain

Taiwan

Tunisia

Uruguay

Generics may enter earlier, or later, based on new patent filings, patent extensions, patent invalidation, early generic licensing, generic entry preferences, and other factors.

See the table below for additional patents covering XACDURO (COPACKAGED) around the world.

Country	Patent Number	Title	Estimated Expiration
Australia	2015350128
Brazil	112017010132
Canada	2966632

XACDURO Investment Analysis: Commercial Fundamentals, Patent Protection, and Generic Risk

Last updated: July 31, 2026

XACDURO, the U.S. brand for sulbactam-durlobactam, is an AstraZeneca antibiotic approved for hospital-acquired and ventilator-associated bacterial pneumonia caused by susceptible strains of Acinetobacter baumannii-calcoaceticus complex. Its investment profile combines high medical need and differentiated antibacterial activity with a narrow patient population, hospital procurement complexity, and limited near-term revenue visibility.

The central investment issue is whether XACDURO becomes a standard treatment for carbapenem-resistant Acinetobacter baumannii infections or remains a specialty rescue antibiotic with modest sales. AstraZeneca acquired Entasis Therapeutics, the drug’s developer, in 2022, before the FDA approval. [1][2]

What is XACDURO and how does it work?

XACDURO combines sulbactam, a beta-lactam antibiotic, with durlobactam, a beta-lactamase inhibitor.

Sulbactam has direct antibacterial activity against A. baumannii. Durlobactam inhibits several class A, C and D beta-lactamases that otherwise degrade sulbactam. The combination is administered intravenously and is dosed every six hours in adults with normal renal function. Dose adjustment is required for renal impairment. [3]

Attribute	XACDURO
Active ingredients	Sulbactam and durlobactam
U.S. brand	XACDURO
FDA approval	May 23, 2023
FDA application	NDA 216974
Dosage form	Intravenous infusion
Approved indication	Hospital-acquired and ventilator-associated bacterial pneumonia caused by susceptible A. baumannii-calcoaceticus complex
Sponsor	Entasis Therapeutics at development; AstraZeneca after acquisition
Primary setting	Inpatient hospitals and intensive-care units
Administration	Intravenous, generally every six hours
Main competitive category	Antibiotics for carbapenem-resistant Gram-negative infections

The FDA approval was supported by the Phase 3 ATTACK trial, which compared sulbactam-durlobactam with colistin in patients with serious A. baumannii infections. XACDURO demonstrated noninferior 28-day all-cause mortality and had a more favorable renal safety profile than colistin. [4]

What is the commercial market for XACDURO?

The addressable market is clinically important but commercially narrow.

Carbapenem-resistant A. baumannii is classified by the World Health Organization as a critical-priority pathogen. The organism is concentrated in hospital and intensive-care settings, where treatment decisions are influenced by local resistance patterns, infectious-disease specialists, antimicrobial stewardship programs and hospital formularies. [5]

XACDURO’s commercial drivers include:

• Increasing prevalence of carbapenem-resistant A. baumannii.
• Use in high-acuity patients with limited treatment options.
• Preference over colistin where renal toxicity is a concern.
• Hospital demand for targeted therapies against antimicrobial resistance.
• Potential use before susceptibility results when clinical risk is high.

The principal commercial constraints are:

• A single primary pathogen target.
• Intravenous administration.
• Restricted hospital use.
• Limited outpatient opportunity.
• Competition from cefiderocol, polymyxins, high-dose ampicillin-sulbactam and other off-label regimens.
• Stewardship policies designed to preserve new antibiotics for resistant infections.
• Reimbursement and formulary adoption that vary across hospitals.

XACDURO is therefore unlikely to resemble a broad-spectrum outpatient antibiotic franchise. Its value depends on clinical adoption, hospital protocols and the growth of drug-resistant infections.

How does XACDURO compare with competing antibiotics?

XACDURO versus cefiderocol

Cefiderocol, marketed as FETROJA by Shionogi, has a broader gram-negative antibacterial profile and is approved for certain complicated urinary tract infections, hospital-acquired bacterial pneumonia and ventilator-associated bacterial pneumonia. XACDURO has a narrower label but is specifically designed to restore sulbactam activity against A. baumannii. [6]

Factor	XACDURO	FETROJA
Key commercial target	A. baumannii	Multiple resistant Gram-negative pathogens
Administration	IV	IV
Primary differentiation	Direct sulbactam activity protected by durlobactam	Siderophore cephalosporin mechanism
Label breadth	Narrower	Broader
Main use case	Suspected or confirmed A. baumannii infection	Broader resistant Gram-negative infections
Competitive risk	Narrow market concentration	Wider competition across several pathogens

XACDURO may gain share when microbiology confirms A. baumannii, while cefiderocol may retain an advantage when the pathogen is unknown or resistance mechanisms are diverse.

XACDURO versus colistin

Colistin remains a low-cost fallback but has significant nephrotoxicity concerns. XACDURO’s ATTACK data support a clinical safety advantage over colistin, which can justify premium pricing in critically ill patients. [4]

XACDURO versus high-dose ampicillin-sulbactam

High-dose ampicillin-sulbactam is an important alternative because sulbactam itself has activity against A. baumannii. Resistance can limit effectiveness, which creates the biological rationale for pairing sulbactam with durlobactam. Hospitals may continue using high-dose generic therapy when susceptibility data, cost controls or local protocols favor it.

What patents protect XACDURO?

XACDURO’s protection is expected to rely on patents covering the active ingredients, the sulbactam-durlobactam combination, pharmaceutical compositions and methods of treating bacterial infections.

The practical patent estate is likely to include several layers:

Protection layer	Relevance
Durlobactam compound patents	Protect the beta-lactamase inhibitor itself
Combination patents	Cover sulbactam administered with durlobactam
Pharmaceutical composition patents	Cover dosage forms and injectable compositions
Method-of-use patents	Cover treatment of A. baumannii infections and related indications
Manufacturing patents	May cover intermediates, synthesis and process conditions
Regulatory exclusivity	May delay approval of competing applications even without patent litigation

For investment analysis, the strongest protection is usually the composition-of-matter patent covering durlobactam or a commercially relevant combination. Formulation and method-of-use patents can extend protection but may be more vulnerable to validity and noninfringement challenges.

Exact patent coverage should be assessed against the current FDA Orange Book, USPTO records and any Paragraph IV litigation docket. Patent expiration dates can differ because of patent-term adjustment, patent-term extension, pediatric exclusivity and terminal disclaimers. [7][8]

When does XACDURO lose exclusivity?

The FDA approved XACDURO in 2023, but approval date alone does not establish the generic-entry date.

Potential exclusivity mechanisms include:

• Five-year new chemical entity exclusivity, if the FDA classified the relevant active ingredient or drug product as eligible.
• Three-year clinical-investigation exclusivity for a new indication or formulation, where applicable.
• Patent-term adjustment.
• Patent-term extension for qualifying regulatory delay.
• Orphan-drug exclusivity only if the product received an orphan designation and approval for the relevant orphan indication.

The most important commercial date is the earliest enforceable generic or authorized-competitive entry date, not the nominal expiration of one patent. For a small hospital antibiotic, a generic entrant could pressure price quickly if it obtains approval and hospital access.

What generic entry risks exist?

A generic applicant could pursue an Abbreviated New Drug Application with Paragraph IV certifications against listed patents. Potential challenges could target:

• Whether listed patents claim the approved product.
• Validity of durlobactam composition claims.
• Obviousness of the combination.
• Written description and enablement.
• Infringement of method-of-use claims.
• Patent-listing compliance under the FDA’s Orange Book rules.

A Paragraph IV notice would likely trigger patent litigation if AstraZeneca or another patent holder sued within the statutory period. Such litigation could delay approval for up to 30 months, subject to court decisions and settlement terms. [9]

What is the FDA regulatory status of XACDURO?

XACDURO received traditional FDA approval for hospital-acquired and ventilator-associated bacterial pneumonia caused by susceptible A. baumannii-calcoaceticus complex. The FDA label includes warnings concerning hypersensitivity, Clostridioides difficile-associated diarrhea, infusion-related reactions and adverse effects associated with antibacterial therapy. [3]

The FDA approval does not establish broad approval for all resistant Gram-negative infections. Physicians may use antibiotics off label, but label breadth affects marketing, clinical guidelines, payer review and the strength of method-of-use patent claims.

The drug may also benefit from the policy environment supporting antibiotics for serious resistant infections, including FDA programs intended to encourage development for limited populations. These programs can improve regulatory access but do not eliminate the commercial challenge of treating relatively small patient populations.

How strong is the XACDURO patent estate?

The patent estate has potentially high technical value but moderate commercial durability.

Its strengths are:

• A differentiated mechanism tied to a defined resistance problem.
• Limited direct substitutes for susceptible A. baumannii infections.
• Possible composition-of-matter protection for durlobactam.
• Clinical evidence supporting lower nephrotoxicity than colistin.
• A hospital-use profile that makes physician preference and microbiology data important.

Its weaknesses are:

• Narrow pathogen coverage.
• Potential reliance on combination and method-of-use claims after composition patents expire.
• Possible generic substitution through alternative sulbactam-containing regimens.
• A market in which stewardship limits volume.
• The possibility that future resistance mechanisms reduce clinical utility.

The estate is stronger if core durlobactam claims extend into the mid-2030s or later and weaker if meaningful protection depends mainly on combination or method patents.

Which companies could challenge XACDURO?

Likely challengers would include large generic manufacturers with sterile injectable capacity, such as Sandoz, Teva, Viatris, Fresenius Kabi, Hikma, Cipla or Sun Pharmaceutical Industries. A challenge would require manufacturing capability, regulatory resources and a commercial rationale for entering a specialized hospital market.

The most credible competitive threat may not be an immediate generic. It may be branded competition from:

• Cefiderocol.
• New beta-lactamase inhibitor combinations.
• Novel agents targeting carbapenem-resistant Gram-negative organisms.
• Improved rapid diagnostic testing.
• Generic sulbactam-based treatment protocols.

What revenue exposure does XACDURO create for AstraZeneca?

AstraZeneca does not separately identify XACDURO as a major reported product in its principal revenue disclosures. That indicates that current revenue exposure is immaterial relative to AstraZeneca’s oncology, respiratory and cardiovascular portfolios. [10]

The investment case is therefore asymmetric:

• A strong launch could create a valuable specialty antibiotic asset and improve AstraZeneca’s antimicrobial-resistance position.
• A weak launch would have limited effect on consolidated AstraZeneca earnings.
• The acquisition provides strategic optionality without making group performance dependent on XACDURO.
• The asset’s value is more relevant to pipeline quality, hospital-antibiotic capabilities and future licensing than to near-term group revenue.

What generic launch scenarios should investors monitor?

Scenario	Commercial effect
No generic challenge before core patent expiry	Sustained premium pricing and formulary expansion
Paragraph IV challenge followed by settlement	Earlier competitive uncertainty; possible licensed entry
First generic after patent expiry	Rapid price erosion but limited unit-volume expansion
Clinical resistance reduces use	Lower demand despite patent protection
Guideline adoption expands use	Higher hospital penetration and stronger franchise value
Cefiderocol or new agents gain preference	Reduced share in empiric and resistant-infection treatment

The key monitoring points are Orange Book listings, Paragraph IV notices, FDA approval activity, hospital formulary decisions, susceptibility trends, clinical-guideline updates and AstraZeneca’s disclosure of product sales.

Key Takeaways

• XACDURO is a targeted hospital antibiotic for serious A. baumannii infections.
• Its clinical differentiation is strongest against colistin because of renal-safety considerations.
• Its commercial market is narrow and dependent on resistant-infection prevalence and hospital adoption.
• Cefiderocol is the principal branded comparator, while high-dose generic ampicillin-sulbactam remains an important alternative.
• Patent value depends primarily on the duration and enforceability of durlobactam and combination protection.
• Paragraph IV litigation is a credible future risk, but the size of the market may limit generic incentives.
• XACDURO is strategically relevant to AstraZeneca but is not a material consolidated-revenue driver based on public product disclosures.
• The investment thesis favors clinical differentiation and antimicrobial-resistance exposure over near-term revenue scale.

FAQs

Is XACDURO a biologic or a small-molecule drug?

XACDURO is a small-molecule antibacterial drug. It is not a biologic and therefore is not exposed to biosimilar competition. Competitive entry would generally occur through generic-drug pathways.

Does XACDURO have an orphan-drug exclusivity period?

Orphan-drug exclusivity depends on the FDA designation and approved indication. The principal FDA approval is for hospital-acquired and ventilator-associated bacterial pneumonia caused by susceptible A. baumannii-calcoaceticus complex. The applicable exclusivity should be confirmed in FDA regulatory records rather than inferred from the antibiotic’s limited market.

What is the main manufacturing barrier for XACDURO?

The main barriers are sterile injectable manufacturing, control of durlobactam quality attributes, combination-product consistency and hospital supply reliability. These barriers can discourage small generic entrants but do not prevent large injectable manufacturers from competing.

Can hospitals substitute generic ampicillin-sulbactam for XACDURO?

Hospitals can use alternative regimens when clinically appropriate, including high-dose ampicillin-sulbactam. Substitution depends on susceptibility results, local resistance patterns, infectious-disease guidance and patient-specific factors. Generic ampicillin-sulbactam is an important pricing constraint.

What is the largest long-term risk to XACDURO?

The largest long-term risk is a combination of narrow market size and evolving resistance. If resistance mechanisms reduce durlobactam’s ability to restore sulbactam activity, clinical use could decline before patent expiry.

References

1. AstraZeneca. (2022). AstraZeneca completes acquisition of Entasis Therapeutics.
2. U.S. Food and Drug Administration. (2023). FDA approves new treatment for hospital-acquired bacterial pneumonia caused by Acinetobacter baumannii.
3. U.S. Food and Drug Administration. (2023). XACDURO prescribing information.
4. Kaye, K. S., et al. (2023). Sulbactam-durlobactam versus colistin for the treatment of serious infections caused by Acinetobacter baumannii-calcoaceticus complex: A randomized clinical trial. The Lancet Infectious Diseases.
5. World Health Organization. (2024). Bacterial priority pathogens list, 2024.
6. U.S. Food and Drug Administration. (2019). FETROJA prescribing information.
7. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations.
8. United States Patent and Trademark Office. (2024). Patent term adjustment and patent term extension resources.
9. U.S. Food and Drug Administration. (2024). ANDA, 505(b)(2), and Paragraph IV patent certification guidance.
10. AstraZeneca. (2024). Annual report and Form 20-F.