Last updated: August 14, 2026
FERIDEX I.V. was a discontinued MRI contrast agent containing ferumoxides, a superparamagnetic iron oxide used to improve liver imaging. The product received FDA approval in 1996 but lost commercial viability as MRI practice shifted toward gadolinium-based agents, newer liver-specific imaging products, and more efficient diagnostic workflows. Public filings do not disclose a durable standalone revenue stream for FERIDEX I.V.; available evidence indicates a niche product with declining demand rather than a growing franchise.
What was FERIDEX I.V. used for?
FERIDEX I.V. was an intravenously administered superparamagnetic iron oxide contrast agent. Its FDA-approved use was to enhance magnetic resonance imaging of the liver and support detection of focal hepatic lesions, including metastatic disease and hepatocellular lesions (U.S. Food and Drug Administration [FDA], 1996).
The product worked through uptake of iron oxide particles by Kupffer cells in normal liver tissue. Lesions with reduced or absent Kupffer-cell activity remained relatively brighter on T2-weighted MRI sequences, creating lesion-to-liver contrast.
| Attribute |
FERIDEX I.V. |
| Active ingredient |
Ferumoxides |
| Drug class |
Superparamagnetic iron oxide MRI contrast agent |
| Route |
Intravenous infusion |
| Original indication |
Liver MRI enhancement |
| FDA application |
NDA 020111 |
| FDA approval |
1996 |
| Primary commercial use |
Detection and characterization of focal liver lesions |
| Current U.S. status |
Discontinued |
| Biosimilar relevance |
None |
| Generic relevance |
Limited, because the product is discontinued and commercially obsolete |
When did FERIDEX I.V. lose exclusivity?
FERIDEX I.V. no longer has meaningful U.S. market exclusivity. The relevant exclusivity period ended many years ago, and the product is listed in FDA discontinued-drug records rather than as an actively marketed reference product.
The FDA label identifies FERIDEX I.V. as NDA 020111. FDA’s Orange Book framework does not provide an active patent or exclusivity barrier supporting current commercial protection for the product (FDA, n.d.-a). Any original composition, formulation, or manufacturing patents associated with ferumoxides would have been filed before the 1996 approval and would generally have expired by the 2010s, subject to any applicable patent-term adjustment or extension.
There is no current FERIDEX I.V. exclusivity period comparable to the market protection attached to a newly approved small-molecule drug.
FERIDEX I.V. exclusivity timeline
| Period |
Event |
| Pre-1996 |
Ferumoxides development and licensing activity |
| 1996 |
FDA approval of FERIDEX I.V. |
| Late 1990s to 2000s |
Commercial use in liver MRI |
| 2000s |
Increasing competition from gadolinium-based liver imaging agents |
| Around the late 2000s or early 2010s |
U.S. commercial withdrawal and declining availability |
| Current status |
Discontinued U.S. product with no active commercial exclusivity |
What is the Orange Book status of FERIDEX I.V.?
FERIDEX I.V. does not have a meaningful active Orange Book patent position. The product’s NDA remains useful for regulatory history, but the discontinued status materially limits its commercial value.
The Orange Book distinguishes between approved drug applications, listed patents, and active marketing status. FERIDEX I.V.’s historical approval does not create a current barrier to alternative iron oxide formulations or other MRI contrast agents. A potential entrant would still face technical and regulatory requirements, but not a durable Orange Book exclusivity wall.
No active Paragraph IV campaign is associated with FERIDEX I.V. in the public record reviewed for this analysis. That outcome is commercially rational: a Paragraph IV challenge is valuable when the reference product has substantial ongoing sales. FERIDEX I.V. lacks that revenue base.
What patents protected FERIDEX I.V.?
FERIDEX I.V. was protected historically by intellectual property covering iron oxide particles, particle coatings, injectable suspensions, imaging applications, and manufacturing processes. The product’s commercial protection was likely distributed across platform patents and product-specific know-how rather than one dominant patent that remains enforceable today.
The principal patent categories were:
Composition and particle patents
These patents covered the size, magnetic properties, surface chemistry, and colloidal stability of superparamagnetic iron oxide particles. Particle-size control was important because it affected biodistribution, liver uptake, magnetic relaxation, and safety.
Formulation patents
Formulation protection related to aqueous suspensions, coating materials, pH control, preservatives, aggregation control, and injectable stability. These characteristics were central to the product’s manufacturing profile.
Method-of-use patents
Method-of-use claims covered MRI imaging of hepatic lesions using iron oxide contrast particles. Such claims would have had limited commercial value once alternative contrast agents provided similar or superior diagnostic performance.
Manufacturing and know-how
Manufacturing know-how likely remained more important than patent exclusivity after the original patents expired. Reproducing a stable injectable iron oxide suspension requires control over particle synthesis, coating uniformity, residual reagents, sterility, aggregation, and release testing.
No current patent expiration date should be treated as a commercial barrier for FERIDEX I.V. itself. The relevant protection has expired or has become commercially immaterial.
How did competition affect FERIDEX I.V.?
FERIDEX I.V. competed in a rapidly changing MRI contrast market. Its commercial position weakened for four main reasons.
First, gadolinium-based agents were more familiar to radiologists and imaging centers. They supported broad MRI applications and fit established contrast-delivery workflows.
Second, liver-specific gadolinium products offered stronger competitive positioning for hepatobiliary imaging. Products such as gadoxetate disodium provided liver uptake and hepatobiliary-phase imaging, creating a more differentiated diagnostic proposition than a reticuloendothelial iron oxide agent.
Third, FERIDEX I.V. required specialized infusion and imaging protocols. Workflow complexity can reduce adoption when competing agents are easier to administer and have broader labels.
Fourth, ferumoxides generated safety and tolerability concerns typical of intravenous particulate products, including infusion reactions and hypersensitivity risk. Even where the clinical benefit was recognized, risk-management and operational requirements affected purchasing decisions.
FERIDEX I.V. compared with competing MRI contrast agents
| Factor |
FERIDEX I.V. |
Gadolinium extracellular agents |
Gadoxetate disodium |
| Imaging target |
Primarily liver lesion detection |
Broad MRI use |
Liver-specific imaging |
| Biological behavior |
Kupffer-cell uptake |
Extracellular distribution |
Hepatocyte and biliary uptake |
| Workflow |
Specialized infusion and liver protocol |
Familiar, broad workflow |
Established liver MRI workflow |
| Commercial breadth |
Narrow |
Broad |
Narrow but differentiated |
| Current market status |
Discontinued |
Widely used class |
Active marketed product |
| Patent value today |
Historical |
Product-specific |
Product-specific and formulation-dependent |
What was the financial trajectory of FERIDEX I.V.?
FERIDEX I.V. appears to have followed a niche-product trajectory: initial clinical adoption, limited expansion, increasing competitive pressure, and eventual commercial withdrawal.
Public company filings do not provide a consistently reported standalone revenue series for FERIDEX I.V. Revenue was historically affected by licensing and distribution arrangements, and reported figures may have been embedded within broader diagnostic-imaging or contrast-agent categories. A reliable product-level sales curve therefore cannot be constructed from public financial disclosures alone.
The commercial trajectory can be summarized as follows:
- The product entered a specialized liver-imaging market after FDA approval.
- Adoption remained limited relative to broad-use gadolinium agents.
- The product faced substitution from improved MRI protocols and liver-specific gadolinium products.
- Manufacturing and distribution economics became less attractive as volume declined.
- The product was discontinued rather than defended through an expensive patent or litigation strategy.
Revenue exposure
FERIDEX I.V. did not become a material revenue driver for a large diversified pharmaceutical company. Its commercial value was constrained by:
- A narrow indication.
- Limited procedure volume relative to general MRI contrast agents.
- Specialized administration requirements.
- Competition from products with broader or more differentiated imaging use.
- Declining physician familiarity after withdrawal.
- Lack of a high-growth label expansion strategy.
For investors, the principal conclusion is that FERIDEX I.V. represented low current revenue exposure and no meaningful forward earnings contribution. Any historical royalty stream would have been subordinate to the commercial performance of the licensee or distributor and would not support a current valuation thesis.
Did FERIDEX I.V. face Paragraph IV challenges or generic entry?
No commercially significant Paragraph IV challenge is associated with FERIDEX I.V. The product’s market decline reduced the incentive for an ANDA sponsor to invest in bioequivalence, analytical characterization, clinical bridging, manufacturing scale-up, and regulatory review.
Generic entry would also have been technically more difficult than a conventional tablet or simple injectable. A generic applicant would need to demonstrate control over:
- Particle-size distribution.
- Magnetic relaxation properties.
- Surface coating and colloidal stability.
- Iron concentration and dosing consistency.
- Sterility and particulate limits.
- Infusion compatibility.
- Pharmacokinetic or imaging comparability.
These requirements create manufacturing and regulatory barriers even after patent expiry. They are technical barriers, not durable exclusivity rights.
What FDA regulatory issues affected FERIDEX I.V.?
FERIDEX I.V. was approved as a drug under an NDA rather than as a medical device. Its regulatory value depended on the approved liver-imaging indication, product quality, intravenous safety, and clinical performance.
The FDA label identified risks associated with hypersensitivity and infusion administration. The product’s clinical utility also depended on radiologist interpretation and appropriate MRI protocols. As the diagnostic market evolved, a narrow indication and specialized protocol became less attractive compared with contrast agents that could be used across multiple MRI examinations.
FDA’s discontinued-drug records are important because they distinguish commercial withdrawal from a product that was never approved. FERIDEX I.V. was an approved product that later ceased commercial distribution. The public record does not establish that withdrawal resulted from a safety-driven FDA action. Commercial demand and competitive conditions were central to the product’s decline (FDA, n.d.-b).
What licensing deals affected FERIDEX I.V.?
Ferumoxides originated from the superparamagnetic iron oxide contrast-agent development programs associated with Advanced Magnetics and subsequent commercial partners. Licensing and distribution arrangements placed commercialization in the hands of larger pharmaceutical companies with established diagnostic-imaging sales channels.
The commercial structure reduced the economic importance of the original developer’s direct sales force but also limited control over global positioning, manufacturing decisions, and post-approval investment. Once demand fell, a licensee had fewer reasons to maintain production, inventory, and field support for a specialized product.
Public filings do not indicate a current licensing transaction that gives FERIDEX I.V. material commercial value. Historical licensing rights should not be confused with active patent protection or current market exclusivity.
What patent litigation affected FERIDEX I.V.?
FERIDEX I.V. does not have a known active U.S. patent-litigation profile that affects current market entry. There is no evident ongoing dispute involving a branded FERIDEX I.V. launch, an ANDA sponsor, or a settlement agreement governing generic entry.
The absence of litigation reflects the product’s commercial status. Patent litigation is costly and generally justified by substantial remaining sales, a viable launch opportunity, or a strategic platform dispute. Those conditions are not apparent for a discontinued liver MRI agent.
Is there biosimilar risk for FERIDEX I.V.?
Biosimilar risk is not applicable. FERIDEX I.V. is not a biologic and does not use the BLA pathway. Any future competing product would be evaluated through a drug pathway, likely requiring an NDA or an ANDA depending on the product’s formulation, reference-product status, and ability to establish pharmaceutical equivalence.
A future iron oxide MRI agent would face a more important question than patent infringement: whether it could generate sufficient clinical and commercial value to justify development and manufacturing investment.
What generic launch scenarios exist for FERIDEX I.V.?
A conventional generic launch is unlikely to create material market disruption because the branded product has already exited the market.
Three scenarios are relevant:
Reintroduction by a specialty manufacturer
A specialty contrast-agent company could revive the product or develop a substantially similar ferumoxides injection for niche liver imaging. This would require renewed manufacturing validation, regulatory strategy, supply-chain investment, and physician adoption.
New iron oxide imaging product
A sponsor could use the ferumoxides platform for a new indication, such as macrophage imaging, lymph-node imaging, or theranostic applications. Such a product would require new clinical evidence and would not depend solely on FERIDEX I.V.’s historical indication.
No commercial re-entry
The most likely scenario is continued absence from the U.S. market. Existing imaging alternatives reduce the economic incentive to restore a discontinued product with a narrow label and complex injectable manufacturing process.
How strong is the FERIDEX I.V. patent estate?
The historical patent estate was technically meaningful but commercially weak today.
| Dimension |
Assessment |
| Historical composition protection |
Moderate to strong, depending on claim scope |
| Historical formulation protection |
Relevant to injectable stability and particle control |
| Method-of-use protection |
Narrow and vulnerable to design-around |
| Current patent life |
No meaningful active exclusivity identified |
| Manufacturing barrier |
Moderate to high |
| Regulatory barrier |
Moderate to high |
| Litigation risk |
Low |
| Revenue protection |
None in the current U.S. market |
| Re-launch attractiveness |
Low without a new clinical or commercial proposition |
Geographic coverage may have differed by jurisdiction because patent filings, term adjustments, national-stage prosecution, and product approvals were not identical worldwide. Even where historical patents existed, the core economic issue is market demand, not remaining patent life.
Key Takeaways
- FERIDEX I.V. was an FDA-approved ferumoxides MRI contrast agent for liver imaging.
- The product was discontinued after losing ground to gadolinium-based and liver-specific MRI contrast agents.
- No active Orange Book exclusivity or commercially meaningful patent barrier supports the product today.
- No material Paragraph IV challenge, biosimilar pathway, or active patent litigation is associated with FERIDEX I.V.
- Historical licensing arrangements supported commercialization but do not create current revenue value.
- Product-level revenue is not consistently disclosed in public filings, preventing a reliable standalone sales forecast.
- Manufacturing complexity remains a barrier to generic or specialty re-entry.
- The most credible commercial opportunity would require a new indication or a differentiated iron oxide imaging platform, not simple restoration of the historical product.
FAQs
Is FERIDEX I.V. still available in the United States?
No. FERIDEX I.V. is a discontinued U.S. product and is not a current mainstream MRI contrast option.
What is the difference between FERIDEX I.V. and Feraheme?
FERIDEX I.V. contained ferumoxides for MRI liver imaging. Feraheme contains ferumoxytol and is approved for treatment of iron-deficiency anemia in certain patient populations. They are distinct products with different approvals, formulations, dosing, and commercial markets.
Could ferumoxides be redeveloped for cancer imaging?
Yes. Ferumoxides could theoretically support macrophage, lymph-node, tumor-microenvironment, or other imaging applications. Redevelopment would require new clinical evidence and a current regulatory strategy.
Did FERIDEX I.V. generate significant pharmaceutical revenue?
Available public disclosures do not show FERIDEX I.V. as a major standalone revenue contributor. Its economics were consistent with a specialized, low-volume diagnostic product.
Does FERIDEX I.V. have a current generic equivalent?
There is no widely established U.S. generic equivalent with the same commercial presence as the original FERIDEX I.V. product. The absence of a generic reflects limited market demand and technical development barriers, not a current branded patent monopoly.
References
- Bayer HealthCare Pharmaceuticals. (2008). FERIDEX I.V. (ferumoxides injectable solution) prescribing information.
- U.S. Food and Drug Administration. (1996). FERIDEX I.V. NDA 020111 approval information and labeling.
- U.S. Food and Drug Administration. (n.d.-a). Approved drug products with therapeutic equivalence evaluations: Orange Book.
- U.S. Food and Drug Administration. (n.d.-b). FDA drug products discontinued from marketing.
- Advanced Magnetics, Inc. (2008). Annual report on Form 10-K.
- U.S. Food and Drug Administration. (2024). Drugs@FDA: FDA-approved drugs database.
