ATROMID-S Drug Patent Profile

Which patents cover Atromid-s, and when can generic versions of Atromid-s launch?

Atromid-s is a drug marketed by Wyeth Ayerst and is included in one NDA.

The generic ingredient in ATROMID-S is clofibrate. There is one drug master file entry for this compound. Additional details are available on the clofibrate profile page.

Summary for ATROMID-S

US Patents:	0
Applicants:	1
NDAs:	1
Raw Ingredient (Bulk) Api Vendors:	94
Patent Applications:	5,239
DailyMed Link:	ATROMID-S at DailyMed

US Patents and Regulatory Information for ATROMID-S

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Wyeth Ayerst	ATROMID-S	clofibrate	CAPSULE;ORAL	016099-002	Approved Prior to Jan 1, 1982		DISCN	No	No

ATROMID-S Market Dynamics and Financial Trajectory

Last updated: September 8, 2026

ATROMID-S was a historical brand of clofibrate, a fibrate lipid-lowering drug used to treat hyperlipidemia. Its commercial trajectory ended with loss of clinical preference, competition from newer fibrates and statins, and unfavorable long-term outcome evidence. ATROMID-S has no meaningful current U.S. commercial market, no active branded exclusivity, no relevant biosimilar exposure, and no publicly reported standalone revenue base.

What was ATROMID-S and who marketed it?

ATROMID-S contained clofibrate, also known as ethyl 2-(4-chlorophenoxy)-2-methylpropanoate. The product was supplied primarily as 500-mg capsules for oral administration. Historical U.S. labeling identified Ayerst Laboratories, later associated with Wyeth, as the manufacturer or sponsor of the product.[1]

Attribute	ATROMID-S profile
Active ingredient	Clofibrate
Drug class	Fibrate lipid-regulating agent
Historical use	Hyperlipidemia and elevated cholesterol or triglycerides
Dosage form	Oral capsule
Common historical strength	500 mg
Original commercial era	1960s through late 20th century
Current U.S. status	Discontinued and not an active commercial product
Biosimilar relevance	None
Generic-entry relevance	Historical only
Current branded revenue	No publicly reported material revenue

Clofibrate was among the first widely used fibrate drugs. Its mechanism involved activation of peroxisome proliferator-activated receptor alpha, although the modern understanding of fibrate pharmacology developed after ATROMID-S entered the market.

When did ATROMID-S lose exclusivity?

ATROMID-S lost meaningful commercial exclusivity decades ago. No current patent estate protects the product, and any original composition or manufacturing patents would have expired long before the modern Hatch-Waxman period.

The commercial decline did not depend on a single patent-expiration event. It resulted from three overlapping factors:

1. Generic availability and erosion of branded pricing.
2. Clinical competition from gemfibrozil, fenofibrate, statins, and combination lipid therapies.
3. Deterioration in the risk-benefit profile after long-term cardiovascular-outcome data became available.

Because ATROMID-S is a legacy small-molecule product, the relevant exclusivity periods are historical rather than current.

Exclusivity category	ATROMID-S status
Active composition patent	None identified as commercially relevant
Active formulation patent	None identified
New chemical entity exclusivity	Expired
Pediatric exclusivity	Not relevant
Orphan-drug exclusivity	Not relevant
Patent-term extension	No current commercial effect
Regulatory exclusivity	Expired
Biosimilar exclusivity	Not applicable

What is the FDA regulatory status of ATROMID-S?

ATROMID-S is not an actively marketed U.S. product. Its historical FDA status reflects an older generation of lipid-lowering therapy rather than a current treatment option.

The FDA’s Orange Book is designed to identify approved drug products that have current marketing status or relevant therapeutic-equivalence information. A discontinued product such as ATROMID-S does not create a present-day branded market comparable with currently marketed statins or fibrates.[2]

The regulatory distinction is important:

• Historical approval does not mean that ATROMID-S remains commercially available.
• A discontinued drug may retain historical approval records without having active sales.
• The absence of an active product does not create a current Paragraph IV dispute.
• No current FDA regulatory pathway is supporting an ATROMID-S relaunch.

Clofibrate remains relevant as a pharmacologic and historical compound, but ATROMID-S does not have the regulatory position of an actively marketed prescription product.

What clinical evidence drove the decline of ATROMID-S?

The principal commercial pressure came from long-term clinical evidence that weakened the case for routine clofibrate therapy.

The World Health Organization Cooperative Trial evaluated clofibrate in patients with ischemic heart disease or elevated lipid levels. The study reduced serum cholesterol but did not establish the expected reduction in overall mortality. It also reported adverse effects, including gallbladder disease and other safety concerns.[3]

Subsequent reviews associated clofibrate with:

• Gallstones and biliary complications.
• Gastrointestinal adverse effects.
• Abnormal liver tests.
• Muscle-related toxicity.
• Concerns about long-term safety and cancer signals in historical datasets.
• Limited evidence that cholesterol reduction with clofibrate translated into a favorable total-mortality benefit.

The arrival of statins changed the treatment standard. Statins produced stronger cardiovascular-outcome evidence and became the preferred first-line therapy for most patients requiring pharmacologic lipid lowering. Fenofibrate and gemfibrozil also offered more commercially relevant fibrate options for selected hypertriglyceridemia and mixed-dyslipidemia populations.

How did the competitive landscape affect ATROMID-S?

ATROMID-S competed in a market that shifted from broad lipid reduction to evidence-based cardiovascular risk reduction.

Competitive product or class	Effect on ATROMID-S
Gemfibrozil	Replaced clofibrate in some fibrate-treatment settings
Fenofibrate	Offered a newer fibrate option with stronger commercial positioning
Lovastatin and later statins	Redefined first-line treatment for hypercholesterolemia
Combination lipid therapy	Reduced the role of older single-agent products
Lifestyle and risk-management programs	Limited use of older drugs with unfavorable safety profiles

Clofibrate’s main disadvantage was not simply age. Its commercial position weakened because physicians had access to therapies with better cardiovascular evidence, more favorable prescribing guidance, and stronger commercial support.

How does ATROMID-S compare with fenofibrate and gemfibrozil?

ATROMID-S is commercially obsolete relative to both products.

Factor	Clofibrate / ATROMID-S	Gemfibrozil	Fenofibrate
Current market role	Historical	Limited but active in some markets	Active in many markets
Cardiovascular evidence	Unfavorable or limited by modern standards	Mixed and indication-specific	Used mainly for triglyceride reduction
Statin-combination practicality	Poorer safety profile	Significant interaction concerns	Commonly preferred over gemfibrozil with statins
Current branded opportunity	None	Limited	Product- and market-specific
Regulatory activity	Historical	Active generic markets	Active generic and branded markets

ATROMID-S has no credible pathway to regain market share without a new clinical and regulatory program. That would require evidence capable of overcoming the established position of statins and newer fibrates.

What was the financial trajectory of ATROMID-S?

No reliable public source reports standalone ATROMID-S revenue, unit sales, gross margin, or net sales by year. Historical manufacturers generally reported lipid products within broader cardiovascular or pharmaceutical portfolios rather than disclosing brand-level revenue.

The financial trajectory can therefore be described by commercial phase rather than by audited brand revenue.

Period	Commercial phase	Financial characteristics
1960s to early 1970s	Market introduction and expansion	Branded pricing, limited direct competition, broad use in hyperlipidemia
Late 1970s to 1980s	Evidence-driven pressure	Clinical concerns reduced prescribing momentum
1980s to 1990s	Substitution and generic erosion	Lower prices and competition from other fibrates
1990s to early 2000s	Terminal decline	Statins became the dominant lipid-lowering class
Current period	Commercial discontinuation	No material branded revenue or active U.S. market

The product likely generated its highest economic value before statins became dominant. Revenue then declined through a combination of lower prescribing volume, price erosion, generic substitution, and withdrawal from commercial distribution.

Any estimate of cumulative ATROMID-S revenue would be speculative without archived company sales data, historical prescription audits, or country-specific distributor records. Public company filings do not provide a sufficiently granular basis for a defensible brand-level calculation.

What patents protected ATROMID-S?

No active patent protection is commercially relevant to ATROMID-S today.

Historical protection may have covered:

• Clofibrate as a chemical entity.
• Processes for synthesizing clofibrate.
• Pharmaceutical compositions.
• Capsule formulations.
• Methods for treating hyperlipidemia.

Those rights, if granted, expired many years ago. The product’s current status is therefore determined by clinical obsolescence and discontinuation rather than by an enforceable patent barrier.

Are formulation patents still relevant?

No. A formulation patent could theoretically have extended the commercial life of a particular dosage form, but any historical ATROMID-S formulation rights are expired. There is no current formulation moat supporting branded pricing.

Are method-of-use patents relevant?

No active method-of-use patent is known to create a commercial barrier for clofibrate or ATROMID-S. Historical indications for hyperlipidemia are broad and old. They do not support a modern protected-use strategy.

Were there Paragraph IV challenges or ATROMID-S patent litigation?

No current Paragraph IV challenge materially affects ATROMID-S. Paragraph IV litigation applies when a generic applicant challenges listed patents associated with an active reference product. ATROMID-S is not a current commercial reference product with a live patent strategy.

There is also no material current patent litigation involving the product. Any historical disputes would have limited economic relevance because the underlying product has exited the active market.

Legal issue	Current status
Paragraph IV litigation	None of commercial significance
Active Orange Book patent	None of commercial significance
Patent-term extension dispute	None identified
Formulation litigation	None of current relevance
Method-of-use litigation	None of current relevance
Settlement agreement	No current agreement affecting market entry
Generic launch dispute	Historical only

What generic entry risks exist for ATROMID-S?

Generic entry risk is no longer the principal issue because ATROMID-S has already experienced the economic effects of generic substitution and market abandonment.

For a hypothetical clofibrate relaunch, the commercial risks would be substantial:

• Low achievable price.
• Limited physician demand.
• Weak reimbursement leverage.
• Competition from established lipid-lowering therapies.
• Need for modern safety and cardiovascular-outcome data.
• Potential regulatory scrutiny concerning the product’s historical risk-benefit profile.
• Limited manufacturing incentives for a low-volume legacy compound.

A generic clofibrate product could theoretically be manufactured if regulatory requirements were met, but regulatory feasibility would not translate into a viable commercial market.

What manufacturing and intellectual-property barriers exist?

Manufacturing ATROMID-S would not present the same intellectual-property obstacles associated with a protected modern drug. The active ingredient is an old small molecule, and the synthetic chemistry is not expected to create a meaningful exclusivity barrier.

The more relevant barriers are commercial and regulatory:

• Sourcing and quality control for an obsolete active ingredient.
• Establishing current specifications and impurity controls.
• Demonstrating bioequivalence or other applicable regulatory requirements.
• Validating stability for the finished capsule.
• Maintaining pharmacovigilance for a product with historical safety concerns.
• Securing distribution and reimbursement for a discontinued therapy.

The absence of patent barriers does not improve the investment case. It removes legal protection without creating demand.

What licensing deals involved ATROMID-S?

No material current licensing transaction involving ATROMID-S is publicly reported. The product’s historical corporate ownership appears to have followed the broader pharmaceutical asset history of Ayerst and Wyeth, but those corporate relationships should not be interpreted as an active ATROMID-S licensing platform.

There is no visible current commercial partnership covering:

• Global relaunch rights.
• Regional commercialization.
• New formulation development.
• Combination therapy.
• Modern clinical redevelopment.
• Manufacturing transfer for an active market.

What is the outlook for ATROMID-S revenue?

The forward revenue outlook is effectively zero in the U.S. branded market. A small amount of activity could exist in historical databases, residual international supply channels, or research settings, but no material commercial trajectory is evident.

Revenue driver	Outlook
U.S. branded sales	None expected
U.S. generic sales	No material market
International sales	Country-specific and likely limited
Price growth	Not supported
Volume growth	Not supported
New indications	No active development signal
Licensing value	Minimal
Acquisition value	Limited to historical or archival assets

A relaunch would require a new investment thesis based on an unusual niche indication, low-cost manufacturing, and a new regulatory strategy. Existing evidence does not support that thesis.

Key Takeaways

• ATROMID-S was a historical clofibrate brand for hyperlipidemia.
• Its patents and regulatory exclusivities expired decades ago.
• The product has no meaningful current U.S. commercial market.
• Statins, newer fibrates, and stronger cardiovascular-outcome evidence displaced clofibrate.
• No active Paragraph IV challenge, Orange Book patent dispute, or patent litigation materially affects ATROMID-S.
• Standalone revenue data are not publicly reported, but the brand’s financial trajectory was from early branded growth to generic erosion and eventual commercial discontinuation.
• Manufacturing is not constrained by meaningful current IP, but low demand, regulatory burden, and unfavorable clinical positioning limit relaunch value.
• ATROMID-S has no meaningful biosimilar risk because clofibrate is a small molecule, not a biologic.

FAQs About ATROMID-S

Is ATROMID-S still available in the United States?

No. ATROMID-S is a discontinued historical clofibrate product and is not an active U.S. commercial therapy.

What drug replaced ATROMID-S?

Statins replaced clofibrate for most cholesterol-lowering treatment. Gemfibrozil and fenofibrate replaced it in selected fibrate-treatment settings.

Is clofibrate the same as fenofibrate?

No. Both are fibrates, but they are different active ingredients with different clinical histories, safety profiles, and current market positions.

Does ATROMID-S have an Orange Book patent?

No active Orange Book patent is commercially relevant to ATROMID-S. Any historical patent protection has expired.

Could a company relaunch ATROMID-S?

A relaunch would be technically possible only through a current regulatory pathway, but the commercial case is weak because of limited demand, safety concerns, competition from established therapies, and the lack of a differentiated indication.

References

1. DailyMed. (n.d.). Atromid-S: Clofibrate capsule labeling. U.S. National Library of Medicine.
2. U.S. Food and Drug Administration. (2025). Approved drug products with therapeutic equivalence evaluations: Orange Book.
3. World Health Organization Cooperative Trial Committee. (1978). WHO cooperative trial on primary prevention of ischaemic heart disease using clofibrate to lower serum cholesterol: Final report. The Lancet, 2(8109), 379-385.
4. National Institute of Diabetes and Digestive and Kidney Diseases. (n.d.). Clofibrate. In LiverTox: Clinical and research information on drug-induced liver injury. National Library of Medicine.
5. U.S. Food and Drug Administration. (n.d.). Drugs@FDA: FDA-approved drugs. U.S. Department of Health and Human Services.