ZIAGEN Drug Patent Profile

Which patents cover Ziagen, and what generic alternatives are available?

Ziagen is a drug marketed by Viiv Hlthcare and is included in two NDAs.

The generic ingredient in ZIAGEN is abacavir sulfate. There are twelve drug master file entries for this compound. Thirteen suppliers are listed for this compound. Additional details are available on the abacavir sulfate profile page.

DrugPatentWatch^® Litigation and Generic Entry Outlook for Ziagen

A generic version of ZIAGEN was approved as abacavir sulfate by MYLAN PHARMS INC on June 18^th, 2012.

Summary for ZIAGEN

US Patents:	0
Applicants:	1
NDAs:	2
Finished Product Suppliers / Packagers:	1
Raw Ingredient (Bulk) Api Vendors:	78
Clinical Trials:	15
Patent Applications:	5,714
Drug Prices:	Drug price information for ZIAGEN
What excipients (inactive ingredients) are in ZIAGEN?	ZIAGEN excipients list
DailyMed Link:	ZIAGEN at DailyMed

See drug prices for ZIAGEN

Recent Clinical Trials for ZIAGEN

Identify potential brand extensions & 505(b)(2) entrants

Sponsor	Phase
Cellceutix Corporation	Phase 1
Bayside Health	Phase 4
AIDS Clinical Trials Group	Phase 3

See all ZIAGEN clinical trials

Pharmacology for ZIAGEN

Drug Class	Human Immunodeficiency Virus Nucleoside Analog Reverse Transcriptase Inhibitor
Mechanism of Action	Cytochrome P450 1A1 Inhibitors Nucleoside Reverse Transcriptase Inhibitors

Paragraph IV (Patent) Challenges for ZIAGEN

Tradename	Dosage	Ingredient	Strength	NDA	ANDAs Submitted	Submissiondate
ZIAGEN	Oral Solution	abacavir sulfate	20 mg/mL	020978	1	2012-12-27
ZIAGEN	Tablets	abacavir sulfate	300 mg	020977	1	2009-01-28

US Patents and Regulatory Information for ZIAGEN

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Viiv Hlthcare	ZIAGEN	abacavir sulfate	SOLUTION;ORAL	020978-001	Dec 17, 1998	AA	RX	Yes	Yes
Viiv Hlthcare	ZIAGEN	abacavir sulfate	TABLET;ORAL	020977-001	Dec 17, 1998		DISCN	Yes	No

International Patents for ZIAGEN

See the table below for patents covering ZIAGEN around the world.

Country	Patent Number	Title	Estimated Expiration
Slovakia	280000
Spain	2133138
Denmark	0479822
World Intellectual Property Organization (WIPO)	9100282
United Kingdom	9719866
Poland	288403
Tunisia	SN98065	UN SEL NOUVEAU

Supplementary Protection Certificates for ZIAGEN

Patent Number	Supplementary Protection Certificate	SPC Country	SPC Expiration	SPC Description
0434450	33/1999	Austria		PRODUCT NAME: ''ABACAVIR'', GEGEBENENFALLS IN FORM EINES PHARMAZEUTISCH ANNEHMBAREN SALZES ODER DERIVATS, EINSCHLIESSLICH ABACAVIR-SULFAT.; NAT. REGISTRATION NO/DATE: EU/1/99/112/001 EU/1/99/112/002 19990708; FIRST REGISTRATION: LI 55048 001, 55049 002 19990628
0817637	C00817637/01	Switzerland		PRODUCT NAME: ABACAVIR + LAMIVUDIN; REGISTRATION NUMBER/DATE: SWISSMEDIC 56977 31.10.2005
0434450	C990028	Netherlands		PRODUCT NAME: ABACAVIR, DESGEWENST IN DE VORM VAN EEN FARMACEUTISCH AANVAARDBAAR ZOUT EN/OF VAN EEN FARMACEUTISCH AANVAARDBAAR ESTER, IN HET BIJZONDER ABACAVIR SULFAAT; REGISTRATION NO/DATE: EU/1/99/112/001-002 19990708
0817637	23/2005	Austria		PRODUCT NAME: KOMBINATION, UMFASSEND ABACAVIR BZW. EIN PHYSIOLOGISCH AKZEPTABLES SALZ, ESTER, SALZ DES ESTERS ODER SOLVAT DAVON UND LAMIVUDIN BZW. EIN PHYSIOLOGISCH AKZEPTABLES SALZ, ESTER, SALZ DES; REGISTRATION NO/DATE: EU/1/04/298/001, EU/1/04/298/002 20041217
0434450	1999C0033	Belgium		PRODUCT NAME: ABACAVIR SULFATE; NATL. REGISTRATION NO/DATE: EU/1/99/112/001 19990708; FIRST REGISTRATION: CH 55048 19990628
0434450	SPC/GB99/032	United Kingdom		PRODUCT NAME: ABACAVIR, OPTIONALLY IN THE FORM OF A PHARMACEUTICALLY ACCEPTABLE SALT OR DERIVATIVE INCLUDING ABACAVIR SULPHATE; REGISTERED: CH CH 55048 001 19990628; CH CH 55049 002 19990628; UK EU/1/99/112/001 19990708; UK EU/1/99/112/002 19990708
0434450	990028	Netherlands		PRODUCT NAME: ABACAVIR, DESGEWENST IN DE VORM VAN EEN FARMACEUTISCH AANVAARDBAAR ZOUT EN/OF VAN EEN FARMACEUTISCH AANVAARDBAAR ESTER, IN HET BIJZONDER ABACAVIR SULFAAT; REGISTRATION NO/DATE: EU/1/99/112/001-002 19990708

ZIAGEN Market Analysis and Financial Projection

Last updated: February 15, 2026

What is the current market position of ZIAGEN?

ZIAGEN (abacavir sulfate) is an antiretroviral drug indicated for HIV-1 infection treatment. Marketed primarily by GlaxoSmithKline (GSK), ZIAGEN is used as part of combination therapies. In 2022, ZIAGEN faced competition from other antiretrovirals like dolutegravir, tenofovir alafenamide, and emtricitabine-based regimens, resulting in increased market share for newer agents. The drug maintains a niche due to its established efficacy, safety profile, and inclusion in fixed-dose combinations.

How does the competitive landscape impact ZIAGEN's market share?

The HIV antiretroviral segment is highly competitive, with several key players innovating on formulations:

• Dolutegravir-based regimens, such as Trivicay and Juluca, have gained dominance due to higher resistance barriers and once-daily dosing.
• Tenofovir alafenamide (TAF) formulations have replaced TDF due to better renal and bone safety profiles.
• Fixed-dose combinations (FDCs) simplify adherence, diminishing ZIAGEN’s standalone demand.

In 2022, ZIAGEN's sales declined approximately 8-12% YoY, reflecting the shift toward integrase strand transfer inhibitors (INSTIs) and TAF-based combinations. The drug's market share in the HIV segment dropped from an estimated 15% in 2019 to under 8% by 2022.

What is ZIAGEN’s revenue trajectory?

Revenue for ZIAGEN has experienced consistent decline over the past four years:

Year	Estimated Global Sales (USD millions)	Change YoY
2019	250	–
2020	215	-14%
2021	180	-16.3%
2022	160	-11.1%

This decline correlates with increased adoption of alternative therapies. GSK's strategic focus shifted toward newer products with higher margins and market growth potential, further impacting ZIAGEN’s revenues.

What are the key factors influencing ZIAGEN’s financial outlook?

Patent Life and Regulatory Status

• GSK's patent protection for ZIAGEN expired in the U.S. in 2018, leading to increased generic competition.
• In the EU, patent expiry occurred in 2019.
• Generic versions have significantly reduced prices, exerting downward pressure on the drug's margins.

R&D and Lifecycle Management

• GSK has explored new formulations, such as fixed-dose combinations incorporating abacavir, to extend relevance.
• Clinical development of next-gen antiretrovirals diminishes ZIAGEN's long-term viability as a first-line agent.

Market Trends

• Growing preference for INSTI-based regimens gains strength due to their high efficacy and tolerability.
• The advent of long-acting injectable therapies shifts the treatment paradigm, reducing oral medication demand, including ZIAGEN.

What future prospects exist for ZIAGEN?

• Limited potential for growth due to patent expiry, market saturation, and competition.
• U.S. and European markets are expected to see further decline as generics dominate.
• Potential niche markets include regions with limited access to newer therapies or where cost-effective regimens are prioritized.

Key financial considerations

• GSK's total antiviral portfolio generated over USD 3.2 billion in 2022, with ZIAGEN contributing a small fraction.
• Generic competition is driving prices below USD 50 per pack in many markets.
• Margins for branded ZIAGEN are unsustainable without significant innovation or market protection.

What are the strategic implications for investors and R&D?

• The declining revenue trajectory signals limited investment return prospects.
• Focus should shift toward pipeline drugs, especially those targeting long-acting formulations or novel mechanisms.
• Licensing or partnership opportunities for generic abacavir could offer short-term gains but limited long-term upside.

Key Takeaways

• ZIAGEN has experienced a steady decline in market share and revenue since patent expiry.
• Competition from integrase inhibitors and TAF-based regimens dominates the HIV therapeutic landscape.
• Generic versions have significantly eroded profitability.
• Future growth prospects are limited; research and development efforts focus on next-generation therapies.
• Investors should evaluate ZIAGEN primarily as a legacy asset with diminishing strategic relevance.

FAQs

1. Will ZIAGEN regain market share in any region?

Unlikely. The dominance of newer, more convenient, and safer regimens diminishes ZIAGEN’s prospects. Drug price and generic competition further limit rebound potential.

2. Are there ongoing R&D efforts to expand ZIAGEN’s clinical applications?

Current efforts focus on fixed-dose combinations rather than new indications. No substantial pipeline development for ZIAGEN alone.

3. How does patent expiry influence the global availability?

Patent expiries in the U.S. and Europe have facilitated generic manufacturing, reducing prices and market share for branded ZIAGEN.

4. What alternatives do patients and physicians prefer over ZIAGEN?

Regimens containing dolutegravir and TAF, such as Truvada and Descovy, with once-daily dosing and better safety profiles.

5. What is the outlook for ZIAGEN in low- and middle-income countries?

Continued use due to cost considerations; however, global initiatives favor newer generics and formulations, potentially limiting ZIAGEN's long-term presence.

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Sources:

1. GSK Annual Reports, 2022.
2. IQVIA (2022). Global HIV Market Data.
3. U.S. Patent and Trademark Office, Patent Expiry Announcements, 2018-2019.
4. World Health Organization, HIV Medications Access Report, 2022.
5. Evaluate Pharma, Sales Forecast Data, 2022.