Last updated: August 8, 2026
CORVERT is the former brand name for ibutilide fumarate injection, an intravenous antiarrhythmic used for rapid pharmacologic conversion of atrial fibrillation and atrial flutter. Its commercial value has declined from branded hospital-product economics to a small generic injectable market. FDA exclusivity and practical patent protection have expired, no biosimilar pathway applies, and public sources do not report standalone CORVERT revenue.
What is CORVERT and how does ibutilide work?
CORVERT contains ibutilide fumarate, a Class III antiarrhythmic administered intravenously in a monitored hospital setting. It prolongs cardiac repolarization and increases the likelihood of restoring sinus rhythm in adults with recent-onset atrial fibrillation or atrial flutter.
The FDA-approved product is supplied as a 0.1 mg/mL injection. The labeled adult dose is generally 1 mg administered over 10 minutes for patients weighing at least 60 kg, with a second 1 mg dose permitted if conversion does not occur within 10 minutes after completion of the first dose. Patients weighing less than 60 kg receive a weight-based dose of 0.01 mg/kg [1].
The principal safety issue is QT prolongation and the risk of torsades de pointes. Continuous electrocardiographic monitoring is required during administration and for a period afterward. This monitoring requirement limits use to hospitals and facilities with appropriate cardiac-resuscitation capability.
What conditions does CORVERT treat?
CORVERT is indicated for rapid conversion of atrial fibrillation or atrial flutter to sinus rhythm. It is not a chronic maintenance therapy and is not intended for routine outpatient use.
Its clinical use competes with:
- Electrical cardioversion
- Intravenous amiodarone
- Intravenous procainamide in selected markets and protocols
- Oral or intravenous dofetilide in controlled settings
- Rate-control strategies using beta blockers, calcium-channel blockers, or digoxin
- Observation followed by spontaneous conversion in selected patients
The need for telemetry, the availability of electrical cardioversion, and concern about proarrhythmia constrain the addressable market.
What is the FDA regulatory status of CORVERT?
The FDA approved CORVERT in 1995 under NDA 020916 for ibutilide fumarate injection. The original product was associated with Pharmacia and later with Pfizer through corporate ownership changes. The current US market is primarily supplied through generic ibutilide products rather than a growing branded CORVERT franchise [1, 2].
| Regulatory attribute |
CORVERT / ibutilide status |
| Active ingredient |
Ibutilide fumarate |
| Dosage form |
Intravenous injection |
| Therapeutic category |
Class III antiarrhythmic |
| Original FDA approval |
1995 |
| Primary use |
Rapid conversion of atrial fibrillation or flutter |
| Administration setting |
Hospital or monitored cardiac facility |
| Current commercial structure |
Generic injectable market |
| Biosimilar relevance |
None |
| Prescription status |
Prescription hospital product |
| Key safety limitation |
QT prolongation and torsades de pointes |
The FDA labeling remains commercially relevant for generic ibutilide because generic products must conform to the approved reference-product conditions of use.
When did CORVERT lose exclusivity?
CORVERT lost meaningful market exclusivity many years ago. The product was approved in the mid-1990s, so any original regulatory exclusivity period has expired. The product also sits well beyond the normal commercial life of small-molecule composition patents and early formulation patents.
No current branded exclusivity appears to support a premium CORVERT franchise. The commercial question is therefore generic availability, hospital formulary placement, manufacturing reliability, and purchasing contracts rather than patent-protected pricing.
What is the Orange Book status of CORVERT?
The Orange Book remains the principal FDA source for approved drug products, therapeutic-equivalence evaluations, and listed patents or exclusivities. For an older injectable such as ibutilide, the relevant commercial conclusion is that no active Orange Book patent position is known to provide meaningful blocking protection for the reference product.
The absence of a current blocking patent position has several consequences:
- Generic applicants do not face a significant patent barrier to market entry.
- Paragraph IV litigation is unlikely to be a major current risk driver.
- Pricing is determined by generic competition and hospital procurement.
- Manufacturing capacity and product availability have greater commercial importance than patent enforcement.
The product’s age makes a late-stage Paragraph IV event unlikely unless a company develops a new formulation, delivery system, or method of use and seeks separate protection.
What patents protect CORVERT and ibutilide?
The original CORVERT intellectual-property estate is commercially weak because the drug was approved approximately three decades ago and its core protection has expired.
Composition-of-matter protection
Ibutilide is an established small molecule. Any original composition-of-matter patent associated with the active ingredient would have expired under the standard US patent term framework, subject to any applicable historical patent-term adjustments. Such protection cannot now prevent ordinary generic ibutilide injection products.
Formulation patents
The commercial product is a conventional sterile injectable formulation. No widely recognized, currently enforceable formulation patent is associated with the legacy CORVERT product that would materially prevent generic competition.
Potential formulation innovations could include:
- Improved stability
- Ready-to-use containers
- Reduced dilution requirements
- Alternative concentrations
- Premixed hospital bags
- Packaging that reduces preparation errors
Those improvements could support new patent filings, but they would not automatically protect the underlying ibutilide molecule or prevent sale of standard generic injection.
Method-of-use patents
The approved use, pharmacologic conversion of atrial fibrillation or atrial flutter, is long established. A new patent could theoretically target a narrowly defined patient population, dosing protocol, combination regimen, or monitoring algorithm. Such a patent would face substantial validity and infringement challenges because the core clinical use is disclosed in the longstanding label and medical literature.
How strong is the CORVERT patent estate?
The current patent estate is weak from a commercial exclusivity perspective.
| Patent factor |
Current assessment |
| Core molecule protection |
Expired |
| Original product exclusivity |
Expired |
| Current Orange Book blocking position |
No material active protection identified |
| Formulation protection |
No commercially significant active estate identified |
| Method-of-use protection |
No known broad blocking protection |
| Paragraph IV exposure |
Low as a current market issue |
| Generic substitution risk |
High |
| Litigation leverage |
Minimal |
| Manufacturing barrier |
More important than IP |
The principal barrier to entry is not intellectual property. It is the difficulty of manufacturing and distributing a sterile injectable in a small, low-volume market while maintaining acceptable margins.
Which companies are challenging CORVERT?
There is no meaningful current patent-challenge narrative comparable to major oncology, immunology, or metabolic drugs. Generic manufacturers can enter through the abbreviated new drug application pathway after expiration of the relevant exclusivity and patent protections.
The competitive field may include generic injectable suppliers such as Hikma and other approved manufacturers, depending on current FDA listings, procurement contracts, and product availability. Supplier participation can change because small hospital products are vulnerable to discontinuations, raw-material constraints, manufacturing deviations, and low economic returns.
The relevant competitive distinction is between:
- The former Pfizer-linked branded product
- FDA-approved generic ibutilide injections
- Alternative pharmacologic cardioversion products
- Electrical cardioversion
- Hospital-specific treatment protocols
What is the market size for CORVERT?
A reliable standalone market size for CORVERT is not publicly disclosed. Public company filings generally report products in aggregate therapeutic or hospital-product categories, not as individual legacy injectable brands.
The addressable market is structurally narrow because ibutilide is:
- Used for an acute intervention rather than chronic therapy
- Administered only in monitored settings
- Subject to proarrhythmia warnings
- Replaced in some cases by electrical cardioversion
- Used in a disease area with multiple treatment pathways
- Purchased through hospitals, group purchasing organizations, and institutional contracts
These factors limit volume and reduce the ability of any supplier to sustain high branded pricing after generic entry.
What is the financial trajectory of CORVERT?
CORVERT’s financial trajectory is best characterized as a transition from a protected branded product to a low-revenue generic hospital product.
Commercial phases
| Period |
Commercial position |
Financial implication |
| 1995 to early post-launch period |
Branded FDA-approved injectable |
Higher price and originator economics |
| Generic-entry period |
Multiple-source product |
Price and share pressure |
| Mature generic period |
Hospital procurement product |
Low unit economics and limited revenue growth |
| Current market |
Legacy generic injectable |
Revenue depends on supply, contracts, and availability |
Pfizer does not publicly disclose current CORVERT revenue as a standalone line item. The brand’s contribution to Pfizer’s present financial profile is not material based on public reporting, and the commercial opportunity is now associated with generic suppliers rather than the original innovator.
Revenue drivers
Current ibutilide revenue is influenced by:
- Number of hospitals stocking the product
- Generic supplier count
- Contract awards and purchasing-group arrangements
- Product shortages or discontinuations
- Unit price and injectable manufacturing costs
- Emergency-department and electrophysiology protocols
- Use of electrical cardioversion as an alternative
- Availability of competing antiarrhythmics
Volume growth is unlikely to translate into strong revenue growth because additional supplier participation usually increases price pressure.
Margin profile
Sterile injectables can have higher manufacturing complexity than oral generics. A low-volume product may therefore have an unusual financial profile: limited market size, but occasional pricing strength when supply contracts or a competitor exits.
That pricing strength is not equivalent to durable market power. It can attract new generic supply, trigger hospital switching, or lead providers to use alternative cardioversion methods.
What generic entry risks exist for CORVERT?
Generic entry risk is high because the active ingredient, dosage form, and main indication are mature.
The main scenarios are:
Continued multi-source supply
Several suppliers remain active, and hospitals purchase ibutilide through competitive contracts. Prices stay low, with periodic shortages possible if one manufacturer exits.
Reduced supplier participation
A manufacturer discontinues the product because of low margins or manufacturing costs. Remaining suppliers gain temporary pricing leverage, but the market remains vulnerable to another supply disruption.
Therapeutic substitution
Hospitals reduce use of ibutilide in favor of electrical cardioversion, amiodarone, procainamide, or other protocols. This would reduce demand even if generic supply remains stable.
Branded relaunch
A branded relaunch would require a commercial rationale such as a new ready-to-use presentation, improved packaging, or a supply-guarantee proposition. A relaunch of the legacy injection without differentiation would face weak pricing power.
Does biosimilar competition affect CORVERT?
No. Biosimilars apply to biological products, while ibutilide is a chemically synthesized small molecule. Competition occurs through generic drug approval and therapeutic substitution, not through the biosimilar pathway.
The relevant FDA pathway is an abbreviated new drug application for a therapeutically equivalent generic product, subject to the applicable reference-product and labeling requirements [2, 3].
What patent litigation and settlement agreements affect CORVERT?
No major current US patent litigation or settlement agreement is publicly associated with CORVERT that materially changes its market outlook. The product’s age and expired exclusivity reduce the probability of late-stage originator litigation.
Any future dispute would more likely concern:
- A newly patented formulation
- Manufacturing technology
- Trade secrets
- Supply contracts
- Product quality
- Abbreviated new drug application certification
- A narrowly drafted method-of-use claim
Those issues would relate to a new commercial strategy, not to the legacy CORVERT molecule itself.
How does CORVERT compare with competing cardioversion drugs?
| Product or strategy |
Main advantage |
Main commercial constraint |
| Ibutilide / CORVERT generic |
Rapid pharmacologic conversion; short administration period |
QT prolongation and mandatory monitoring |
| Electrical cardioversion |
High immediate conversion potential |
Requires equipment, sedation, and procedural resources |
| Amiodarone |
Broad use and extensive clinical familiarity |
Slower conversion and systemic toxicity concerns |
| Procainamide |
Used in selected acute arrhythmia protocols |
Hemodynamic and proarrhythmic concerns |
| Dofetilide |
Established rhythm-control role |
Initiation requires inpatient monitoring |
| Rate control |
Avoids immediate rhythm-conversion drug risk |
Does not restore sinus rhythm |
Ibutilide remains clinically differentiated by its intended rapid conversion, but that differentiation does not create strong commercial protection.
What geographic coverage does CORVERT have?
The product’s strongest commercial relevance is in the United States, where FDA-approved ibutilide injection can be purchased for hospital use. International availability varies by country, marketing authorization, local formularies, and generic supplier participation.
The US market is likely to remain a mature, low-growth segment. Geographic expansion would require country-specific approvals and hospital adoption, with limited incentive for large-scale investment in a legacy injectable unless a supplier can secure a defensible manufacturing or distribution position.
Key Takeaways
- CORVERT is the legacy brand for ibutilide fumarate injection.
- FDA approval dates to 1995, and original regulatory exclusivity has expired.
- The active ingredient and conventional injectable presentation do not have meaningful current patent protection.
- No major current Paragraph IV dispute, Orange Book blocking patent, or settlement agreement drives the market.
- Biosimilar risk is irrelevant because ibutilide is a small-molecule drug.
- The market is hospital-based, low volume, and exposed to therapeutic substitution.
- Financial value has shifted from branded originator revenue to generic supply contracts.
- Standalone CORVERT revenue is not publicly disclosed.
- Sterile manufacturing reliability and supplier participation are more important than patent strength.
- The principal commercial risks are generic price erosion, hospital protocol changes, product discontinuation, and supply interruption.
Frequently Asked Questions
Is CORVERT still marketed by Pfizer?
The former Pfizer-associated CORVERT brand does not represent a significant current branded growth franchise. US availability is primarily associated with generic ibutilide injection products.
Is ibutilide a generic drug?
Yes. Ibutilide fumarate injection is available as a generic product in the US, subject to current FDA approvals and supplier availability.
Can a generic manufacturer launch ibutilide without a Paragraph IV challenge?
Yes. For an old product with no relevant unexpired blocking patent, a generic applicant may not need to rely on a Paragraph IV certification against an active patent. The exact certification depends on the FDA reference-product record and any listed patents.
Why do hospitals continue to use ibutilide despite generic competition?
Hospitals may retain ibutilide because it offers rapid pharmacologic conversion in selected patients. Its use depends on cardiac monitoring capacity, physician preference, patient characteristics, and institutional protocols.
Could a new ibutilide formulation receive patent protection?
A new formulation could potentially receive patent protection if it satisfies patentability requirements. Protection would likely cover the specific formulation, container, manufacturing process, or use rather than the already established ibutilide molecule.
References
- U.S. Food and Drug Administration. (2019). Corvert (ibutilide fumarate) injection prescribing information. https://www.accessdata.fda.gov
- U.S. Food and Drug Administration. (n.d.). Drugs@FDA: FDA-approved drugs. https://www.accessdata.fda.gov/scripts/cder/daf/
- U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations, Orange Book. https://www.fda.gov/drugs/drug-approvals-and-databases/approved-drug-products-therapeutic-equivalence-evaluations-orange-book
- DailyMed. (n.d.). Ibutilide fumarate injection labeling. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/
- Pfizer Inc. (2024). Annual report. https://www.pfizer.com/investors/financial-information/annual-reports-and-proxy-statements
