CIMDUO Drug Patent Profile

When do Cimduo patents expire, and what generic alternatives are available?

Cimduo is a drug marketed by Mylan Labs Ltd and is included in one NDA.

The generic ingredient in CIMDUO is lamivudine; tenofovir disoproxil fumarate. There is one drug master file entry for this compound. One supplier is listed for this compound. Additional details are available on the lamivudine; tenofovir disoproxil fumarate profile page.

Summary for CIMDUO

US Patents:	0
Applicants:	1
NDAs:	1
Finished Product Suppliers / Packagers:	1
Drug Prices:	Drug price information for CIMDUO
What excipients (inactive ingredients) are in CIMDUO?	CIMDUO excipients list
DailyMed Link:	CIMDUO at DailyMed

See drug prices for CIMDUO

Pharmacology for CIMDUO

Drug Class	Hepatitis B Virus Nucleoside Analog Reverse Transcriptase Inhibitor Human Immunodeficiency Virus Nucleoside Analog Reverse Transcriptase Inhibitor
Mechanism of Action	Nucleoside Reverse Transcriptase Inhibitors

US Patents and Regulatory Information for CIMDUO

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Mylan Labs Ltd	CIMDUO	lamivudine; tenofovir disoproxil fumarate	TABLET;ORAL	022141-001	Feb 28, 2018		RX	Yes	Yes

CIMDUO Market Dynamics, Patent Position, Exclusivity Timeline, and Financial Trajectory

Last updated: September 24, 2026

CIMDUO is a mature, low-cost fixed-dose HIV treatment containing lamivudine 300 mg and tenofovir disoproxil fumarate 300 mg. ViiV Healthcare received U.S. Food and Drug Administration approval on February 2, 2018, under NDA 209564. The product is indicated with other antiretroviral agents for the treatment of HIV-1 infection in adults and pediatric patients weighing at least 35 kg.[1]

CIMDUO has limited commercial differentiation. Both active ingredients are long-established nucleoside or nucleotide reverse transcriptase inhibitors, and multiple generic or branded alternatives compete in the same treatment segment. The product’s economic value is therefore tied more to procurement access, HIV treatment programs, and portfolio continuity than to premium pricing or patent-protected growth.

No standalone CIMDUO revenue is disclosed in GSK or ViiV financial reporting. Its financial contribution is likely small relative to ViiV’s leading products, including Dovato, Triumeq, Tivicay, and Cabenuva.

What is CIMDUO and how does it compete in HIV treatment?

CIMDUO combines two established antiretroviral ingredients in a single tablet:

Attribute	CIMDUO detail
Active ingredients	Lamivudine and tenofovir disoproxil fumarate
Strength	300 mg/300 mg
Drug class	NRTI combination
FDA application	NDA 209564
U.S. approval	February 2, 2018
Sponsor	ViiV Healthcare Company
Dosage form	Oral tablet
Indication	HIV-1 treatment with other antiretroviral agents
Patient population	Adults and pediatric patients weighing at least 35 kg
Administration	One tablet once daily, with or without food
Therapeutic role	NRTI backbone used with a third antiretroviral agent

CIMDUO is not a complete three-drug HIV regimen. It is used as the nucleoside backbone alongside an integrase inhibitor, protease inhibitor, or another appropriate agent.

Its main clinical competitors include generic lamivudine/tenofovir disoproxil fumarate, Truvada and its generic equivalents containing emtricitabine/tenofovir disoproxil fumarate, and newer tenofovir alafenamide-based products. TAF products can offer renal and bone safety advantages over TDF in some patients, although they often carry higher commercial pricing.

When did CIMDUO lose exclusivity?

CIMDUO’s principal U.S. regulatory exclusivity period expired in 2021.

Because the product combines previously approved active ingredients, it did not receive new chemical entity exclusivity. The relevant protection was likely the three-year exclusivity available for certain new clinical investigations supporting approval of a previously approved active ingredient or combination. That period ran from the February 2, 2018 approval date to approximately February 2, 2021.[1][2]

Protection category	CIMDUO status
New chemical entity exclusivity	Not applicable
Orphan-drug exclusivity	Not applicable
Pediatric exclusivity	No product-specific extension publicly associated with CIMDUO
Three-year clinical-investigation exclusivity	Expired approximately February 2, 2021
Patent-based exclusivity	No meaningful long-term product protection identified in public FDA materials
Current status	Commercially exposed to generic and alternative-product competition

The absence of new chemical entity exclusivity limited CIMDUO’s ability to delay competing applications. Its active ingredients had already been widely used and were associated with older reference products, including Epivir and Viread.

What patents protect CIMDUO?

CIMDUO has a weaker patent profile than newer HIV products such as Cabenuva, Dovato, or Biktarvy.

The relevant intellectual-property categories are:

1. Patents covering lamivudine.
2. Patents covering tenofovir disoproxil fumarate.
3. Combination or formulation patents.
4. Manufacturing and crystalline-form patents.
5. Patents covering treatment methods or patient subgroups.

The foundational composition patents for lamivudine and tenofovir disoproxil fumarate were filed decades before CIMDUO’s approval and have expired or reached the end of their enforceable lives in the United States. CIMDUO did not create a new active pharmaceutical ingredient.

Public FDA product information does not indicate a durable Orange Book patent estate that would materially delay generic competition for the fixed-dose product. The FDA Orange Book remains the controlling source for current listed patent and exclusivity information.[2]

What formulation patents are relevant to CIMDUO?

CIMDUO’s tablet formulation is relatively conventional. Publicly available labeling identifies the active ingredients and inactive ingredients but does not establish a commercially meaningful formulation barrier comparable to long-acting injectable delivery systems or complex modified-release products.[1]

Potential formulation issues include:

• Tablet hardness and stability.
• Co-formulation of two active ingredients.
• Dissolution performance.
• Impurity control.
• Tenofovir disoproxil fumarate degradation.
• Manufacturing scale and supply consistency.

These factors can affect regulatory approval and product quality, but they are not equivalent to a strong blocking patent position. A competing manufacturer may be able to design around a formulation claim by using different excipients, compression conditions, coating systems, or manufacturing processes.

What is the Orange Book status of CIMDUO?

CIMDUO is listed by FDA as an approved prescription drug under NDA 209564. Its regulatory status does not by itself establish continuing patent exclusivity.

The commercial significance of the Orange Book position is limited because:

• The active ingredients are old and broadly available.
• The fixed-dose combination does not have a new chemical entity exclusivity period.
• The principal regulatory exclusivity period has expired.
• The product faces competition from separate-component and combination products.
• Generic applicants can potentially rely on ANDA pathways or other applicable FDA routes, depending on the reference-product and formulation strategy.

A Paragraph IV challenge could target any unexpired listed patent. No major public Paragraph IV litigation campaign directed specifically at CIMDUO has become a defining feature of the product’s commercial history.

Which companies are challenging CIMDUO?

No major publicly documented patent challenger has emerged as a central market event for CIMDUO. The competitive threat is broader and more structural: generic manufacturers can supply lamivudine, tenofovir disoproxil fumarate, and potentially the same fixed-dose combination at lower prices.

Relevant competitors include:

Competitor category	Examples	Competitive effect
Generic lamivudine	Multiple U.S. and international manufacturers	Reduces the value of branded lamivudine combinations
Generic TDF	Multiple manufacturers	Lowers backbone pricing
Generic 3TC/TDF combinations	Market-dependent	Directly competes with CIMDUO
Truvada and generic equivalents	Emtricitabine/TDF	Offers an alternative TDF backbone
TAF-based combinations	Descovy and other products	Offers a newer tenofovir formulation
Integrase-based regimens	Dovato, Triumeq, Biktarvy, Tivicay combinations	Competes for complete-regimen prescribing
Public-sector supply programs	PEPFAR, Global Fund, national tenders	Shift demand toward lowest-cost qualified products

The most significant commercial competition is not an individual patent lawsuit. It is substitution toward lower-cost generic backbones and newer integrase inhibitor regimens.

What is the FDA regulatory status of CIMDUO?

CIMDUO remains an FDA-approved product. The approval supports treatment of HIV-1 infection in combination with other antiretroviral agents.[1]

The product carries standard warnings and precautions associated with its components, including:

• Lactic acidosis and severe hepatomegaly with steatosis.
• Hepatitis B exacerbation after discontinuation of lamivudine or tenofovir therapy.
• Renal toxicity and renal monitoring associated with tenofovir disoproxil fumarate.
• Bone mineral density effects.
• HIV resistance risk if used without an adequate accompanying regimen.

CIMDUO is not indicated for HIV pre-exposure prophylaxis. Its composition differs from Truvada, which contains emtricitabine and tenofovir disoproxil fumarate and has separate approved uses.

How strong is the CIMDUO patent estate?

CIMDUO’s patent estate is weak from a market-exclusivity perspective.

Patent-strength factor	Assessment
New molecular entity protection	None
Remaining core compound protection	None of material commercial duration expected
Combination-product differentiation	Limited
Formulation complexity	Low to moderate
Manufacturing complexity	Moderate, but generally manageable
Method-of-use protection	Narrow relative to product composition
Litigation leverage	Low
Generic substitution risk	High
Lifecycle-management opportunity	Limited

Method-of-use patents could theoretically cover specific treatment populations, dosing protocols, or combinations. Such claims would not necessarily block all generic CIMDUO sales because generic labeling can sometimes omit patented indications under a section VIII strategy, where legally available. Method patents also tend to provide narrower commercial protection than composition patents.

What generic entry risks exist for CIMDUO?

Generic entry risk is high because the key barriers are commercial rather than legal.

A generic manufacturer would need to demonstrate:

• Pharmaceutical equivalence.
• Bioequivalence.
• Appropriate stability.
• Manufacturing compliance.
• Adequate impurity controls.
• Compliance with FDA labeling and safety requirements.

CIMDUO’s once-daily tablet offers convenience, but the convenience premium is limited because competing products also provide once-daily dosing. A generic version could compete on acquisition cost, rebate terms, and public-program eligibility.

The principal launch scenarios are:

Scenario	Market effect
Direct generic 3TC/TDF launch	Rapid price pressure on CIMDUO
Generic components sold separately	Partial substitution, especially in price-sensitive markets
Continued branded supply without major generic launch	Stable but limited niche demand
Shift to TAF products	Erodes TDF-based backbone use
Shift to two-drug or long-acting regimens	Reduces demand for older NRTI backbones
Tender-driven public-sector purchasing	Favors lowest-cost qualified supplier

What patent litigation affects CIMDUO?

No major ongoing U.S. patent litigation involving CIMDUO is publicly associated with the product at the level seen for high-value HIV products.

The absence of high-profile litigation is consistent with the product’s economics. Litigation is less attractive when:

• The product has no new chemical entity protection.
• The underlying ingredients are mature.
• Competing products are widely available.
• Revenue is not separately reported.
• A generic can compete through alternative products rather than directly copying the brand.

No material settlement agreement involving CIMDUO has become a publicly recognized driver of its market timing or generic-entry outlook.

Does CIMDUO face biosimilar risk?

No. CIMDUO is a small-molecule oral tablet, not a biologic. Biosimilar regulation under the Public Health Service Act does not apply.

Its competitive exposure comes from generic-drug pathways, abbreviated new drug applications, branded alternatives, international tender competition, and therapeutic substitution.

How does CIMDUO compare with competing HIV products?

Product	Core ingredients or modality	Commercial position	Main advantage over CIMDUO
CIMDUO	Lamivudine/TDF	Mature branded combination	Low-cost, once-daily NRTI backbone
Truvada	Emtricitabine/TDF	Mature product with generic competition	Established clinical use and broader historical recognition
Descovy	Emtricitabine/TAF	Newer branded backbone	Improved renal and bone profile in relevant patients
Dovato	Dolutegravir/lamivudine	Branded two-drug regimen	Complete regimen with fewer antiretroviral agents
Triumeq	Abacavir/dolutegravir/lamivudine	Established complete regimen	Integrase-based complete regimen
Biktarvy	Bictegravir/emtricitabine/TAF	High-value branded complete regimen	Potent once-daily single-tablet regimen
Cabenuva	Cabotegravir/rilpivirine injectable	Long-acting branded therapy	Reduces daily oral dosing

CIMDUO competes best where price and access dominate prescribing decisions. It is less competitive in settings where clinicians prioritize newer integrase-based regimens, TAF-based renal and bone profiles, or long-acting administration.

What is CIMDUO’s financial trajectory?

CIMDUO’s financial trajectory is likely mature, low-growth, and vulnerable to price erosion.

GSK reports ViiV Healthcare performance at the portfolio level rather than providing separate CIMDUO revenue. Public financial disclosures focus on higher-value products and strategic growth drivers. CIMDUO is not separately identified as a major revenue contributor in the company’s principal annual reporting.[3]

The product’s financial profile can be summarized as follows:

Financial factor	Expected effect
No standalone revenue disclosure	Prevents precise product-level valuation
Expired regulatory exclusivity	Increases generic exposure
Mature active ingredients	Limits pricing power
Public procurement demand	Supports volume but compresses margins
Once-daily convenience	Provides modest retention value
Competition from TAF and integrase regimens	Reduces long-term demand
ViiV commercial infrastructure	Supports continued availability
No major patent litigation	Limits legal-cost burden but also confirms weak exclusivity

CIMDUO may retain value in government programs, emerging markets, and formularies seeking lower-cost NRTI backbones. Volume can remain commercially relevant even when unit pricing is low. That does not translate into a high-growth branded asset.

What licensing deals affect CIMDUO?

No major CIMDUO-specific licensing transaction is publicly identified as a significant driver of the product’s market value.

The relevant commercial relationships are more likely to involve:

• ViiV’s global distribution arrangements.
• Government procurement contracts.
• Public-health program purchasing.
• Regional supply agreements.
• Generic and authorized-generic manufacturing relationships.

The lack of a visible product-specific licensing transaction limits the ability to attribute external royalty value or milestone revenue to CIMDUO.

What geographic markets are most important for CIMDUO?

CIMDUO’s strongest commercial rationale is in markets where:

• HIV treatment is funded through public programs.
• Generic substitution is extensive.
• TDF remains a standard backbone.
• National formularies emphasize acquisition cost.
• Once-daily oral treatment is preferred.
• Access programs require reliable supply from qualified manufacturers.

The United States remains important for regulatory reference and commercial positioning, but the product’s long-term volume opportunity is more closely connected to international procurement and treatment access than to U.S. premium pricing.

Geographic patent exposure is also limited by the age of the active ingredients. Patent status must be assessed country by country, but the foundational U.S. protection for lamivudine and TDF is no longer a durable global barrier. Regulatory, manufacturing, procurement, and quality requirements are more relevant than patent blocking rights in many markets.

Key Takeaways

• CIMDUO is a once-daily lamivudine/TDF tablet approved by FDA in February 2018.
• Its three-year regulatory exclusivity period expired approximately in February 2021.
• The product has no new chemical entity protection and no strong long-term Orange Book patent barrier identified in public FDA materials.
• Generic entry and therapeutic substitution present high commercial risk.
• Biosimilar risk does not apply because CIMDUO is a small-molecule oral drug.
• No major CIMDUO-specific patent litigation or settlement has shaped market entry.
• ViiV does not separately disclose CIMDUO revenue.
• The product is likely a mature, low-margin portfolio asset supported by public procurement and price-sensitive HIV treatment markets.
• Newer TAF-based products, integrase inhibitor regimens, and long-acting injectables are the main long-term sources of substitution risk.
• CIMDUO’s residual value is based on access, affordability, supply reliability, and formulary inclusion rather than patent exclusivity.

FAQs About CIMDUO Market and Patent Exposure

Is CIMDUO still patent protected?

CIMDUO does not appear to have a durable, commercially significant U.S. patent barrier. The active ingredients are old, and the principal regulatory exclusivity period expired in 2021.

Can a generic manufacturer copy CIMDUO?

A manufacturer may pursue an applicable FDA generic pathway if it satisfies bioequivalence, quality, labeling, and manufacturing requirements. Competition can also arise through separate lamivudine and TDF products.

Is CIMDUO the same as Truvada?

No. CIMDUO contains lamivudine and TDF. Truvada contains emtricitabine and TDF. Both are NRTI backbones, but they contain different cytidine analogues.

Does CIMDUO treat HIV by itself?

No. CIMDUO must be used with other antiretroviral agents. It is a two-drug backbone, not a complete HIV treatment regimen.

Is CIMDUO commercially important to ViiV Healthcare?

ViiV does not separately report CIMDUO revenue. Its commercial importance is likely modest relative to ViiV’s newer and higher-value HIV products, although it can retain volume in cost-sensitive and public-sector markets.

References

1. U.S. Food and Drug Administration. (2018). CIMDUO (lamivudine and tenofovir disoproxil fumarate) prescribing information.
2. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations, Orange Book.
3. GSK. (2024). Annual report 2023. London, United Kingdom: GSK plc.