RELISTOR Drug Patent Profile

When do Relistor patents expire, and when can generic versions of Relistor launch?

Relistor is a drug marketed by Salix Pharms and Salix and is included in two NDAs. There are twelve patents protecting this drug and three Paragraph IV challenges.

This drug has one hundred and twenty-three patent family members in thirty-six countries.

The generic ingredient in RELISTOR is methylnaltrexone bromide. There are three drug master file entries for this compound. One supplier is listed for this compound. Additional details are available on the methylnaltrexone bromide profile page.

DrugPatentWatch^® Generic Entry Outlook for Relistor

Relistor was eligible for patent challenges on April 24, 2012.

There have been thirteen patent litigation cases involving the patents protecting this drug, indicating strong interest in generic launch. Recent data indicate that 63% of patent challenges are decided in favor of the generic patent challenger and that 54% of successful patent challengers promptly launch generic drugs.

There is one tentative approval for the generic drug (methylnaltrexone bromide), which indicates the potential for near-term generic launch.

Indicators of Generic Entry

Summary for RELISTOR

International Patents:	123
US Patents:	12
Applicants:	2
NDAs:	2
Finished Product Suppliers / Packagers:	1
Raw Ingredient (Bulk) Api Vendors:	36
Clinical Trials:	18
Patent Applications:	269
Drug Prices:	Drug price information for RELISTOR
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for RELISTOR
What excipients (inactive ingredients) are in RELISTOR?	RELISTOR excipients list
DailyMed Link:	RELISTOR at DailyMed

See drug prices for RELISTOR

Recent Clinical Trials for RELISTOR

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

Sponsor	Phase
University of Alabama at Birmingham	N/A
Odense University Hospital	Phase 2/Phase 3
Asbjørn Mohr Drewes	Phase 2/Phase 3

See all RELISTOR clinical trials

Pharmacology for RELISTOR

Drug Class	Opioid Antagonist
Mechanism of Action	Opioid Antagonists

Paragraph IV (Patent) Challenges for RELISTOR

Tradename	Dosage	Ingredient	Strength	NDA	ANDAs Submitted	Submissiondate
RELISTOR	Tablets	methylnaltrexone bromide	150 mg	208271	1	2016-09-06
RELISTOR	Injection	methylnaltrexone bromide	8 mg/0.4 mL, Single Dose Prefilled Syringe	021964	1	2015-09-08
RELISTOR	Injection	methylnaltrexone bromide	12 mg/0.6 mL, Single Dose Vial	021964	1	2015-07-22

US Patents and Regulatory Information for RELISTOR

RELISTOR is protected by thirteen US patents.

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Salix	RELISTOR	methylnaltrexone bromide	TABLET;ORAL	208271-001	Jul 19, 2016		RX	Yes	Yes	10,376,505		Y
Salix	RELISTOR	methylnaltrexone bromide	TABLET;ORAL	208271-001	Jul 19, 2016		RX	Yes	Yes	8,524,276		Y
Salix Pharms	RELISTOR	methylnaltrexone bromide	SOLUTION;SUBCUTANEOUS	021964-002	Sep 27, 2010		RX	Yes	Yes	8,420,663
Salix Pharms	RELISTOR	methylnaltrexone bromide	SOLUTION;SUBCUTANEOUS	021964-003	Sep 27, 2010		RX	Yes	Yes	8,247,425
Salix	RELISTOR	methylnaltrexone bromide	TABLET;ORAL	208271-001	Jul 19, 2016		RX	Yes	Yes	9,724,343		Y
Salix Pharms	RELISTOR	methylnaltrexone bromide	SOLUTION;SUBCUTANEOUS	021964-002	Sep 27, 2010		RX	Yes	Yes	9,492,445		Y
Salix Pharms	RELISTOR	methylnaltrexone bromide	SOLUTION;SUBCUTANEOUS	021964-001	Apr 24, 2008		RX	Yes	Yes	12,303,592		Y

Expired US Patents for RELISTOR

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	Patent No.	Patent Expiration
Salix Pharms	RELISTOR	methylnaltrexone bromide	SOLUTION;SUBCUTANEOUS	021964-003	Sep 27, 2010	9,669,096
Salix Pharms	RELISTOR	methylnaltrexone bromide	SOLUTION;SUBCUTANEOUS	021964-002	Sep 27, 2010	10,376,584
Salix Pharms	RELISTOR	methylnaltrexone bromide	SOLUTION;SUBCUTANEOUS	021964-003	Sep 27, 2010	8,552,025
Salix	RELISTOR	methylnaltrexone bromide	TABLET;ORAL	208271-001	Jul 19, 2016	6,559,158
Salix Pharms	RELISTOR	methylnaltrexone bromide	SOLUTION;SUBCUTANEOUS	021964-002	Sep 27, 2010	9,669,096
Salix Pharms	RELISTOR	methylnaltrexone bromide	SOLUTION;SUBCUTANEOUS	021964-002	Sep 27, 2010	6,559,158
Salix Pharms	RELISTOR	methylnaltrexone bromide	SOLUTION;SUBCUTANEOUS	021964-002	Sep 27, 2010	8,552,025

EU/EMA Drug Approvals for RELISTOR

Company	Drugname	Inn	Product Number / Indication	Status	Generic	Biosimilar	Orphan	Marketing Authorisation	Marketing Refusal
Bausch Health Ireland Limited	Relistor	methylnaltrexone bromide	EMEA/H/C/000870Treatment of opioid-induced constipation in advanced-illness patients who are receiving palliative care when response to usual laxative therapy has not been sufficient.	Authorised	no	no	no	2008-07-01

International Patents for RELISTOR

When does loss-of-exclusivity occur for RELISTOR?

Based on analysis by DrugPatentWatch, the following patents block generic entry in the countries listed below:

Argentina

Australia

Brazil

Canada

Chile

China

Colombia

Costa Rica

Ecuador

Eurasian Patent Organization

European Patent Office

Georgia, Republic of

Guatemala

Hong Kong

Hungary

Israel

Japan

Malaysia

Mexico

Morocco

New Zealand

Peru

Philippines

Poland

Portugal

Russian Federation

Singapore

South Africa

South Korea

Spain

Taiwan

Tunisia

Ukraine

Generics may enter earlier, or later, based on new patent filings, patent extensions, patent invalidation, early generic licensing, generic entry preferences, and other factors.

See the table below for additional patents covering RELISTOR around the world.

Country	Patent Number	Title	Estimated Expiration
Ecuador	SP088752
Russian Federation	2539387	СОСТАВЫ ДЛЯ ПАРЕНТЕРАЛЬНОЙ ДОСТАВКИ СОЕДИНЕНИЙ И ИХ ПРИМЕНЕНИЕ (FORMULATIONS FOR PARENTERAL DELIVERY OF COMPOUNDS AND USING THEM)
Poland	3178472
Japan	2017206553	メチルナルトレキソンの経口製剤および親油性塩 (ORAL FORMULATIONS AND LIPOPHILIC SALTS OF METHYLNALTREXONE)
Japan	2017101053	末梢オピオイド受容体アンタゴニストおよびその使用 (PERIPHERAL OPIOID RECEPTOR ANTAGONISTS AND USES THEREOF)
Poland	2368553
China	107308125	甲基纳曲酮的口服制剂和亲脂盐 (Oral formulations and lipophilic salts of methylnaltrexone)

Market Dynamics and Financial Trajectory for RELISTOR

Last updated: December 27, 2025

Executive Summary

RELISTOR (methylnaltrexone bromide) is a restricted-use, peripherally acting opioid antagonist indicated primarily for treating opioid-induced constipation (OIC) in advanced illness patients. Since its FDA approval in 2008, its market has evolved amidst changing opioid use patterns, regulatory environments, and competitive drug development. This report provides a comprehensive analysis of RELISTOR’s market dynamics, including demand drivers, competitive landscape, regulatory factors, and financial projections, to assist stakeholders in understanding its current position and future trajectory.

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What Are the Key Market Drivers for RELISTOR?

1. Rising Prevalence of Opioid Use and OIC

• Opioid prescription increase: The global opioid consumption has surged, especially in the U.S., driven by chronic pain management, palliative care, and end-of-life treatments. The CDC reports approximately 50 million Americans used opioids in 2019, with about 30% experiencing OIC.[1]
• OIC burden: OIC affects 40-60% of opioid-treated patients, leading to substantial quality-of-life reductions and healthcare costs.[2]

2. Growing Geriatric Population and Palliative Care

• The aging population expands demand, as elderly patients are more susceptible to both chronic pain and constipation. Globally, individuals aged 65+ are projected to comprise 16% of the population by 2050, increasing OIC incidence.[3]

3. Advances in Opioid Alternatives and Adjuncts

• Limited availability of non-opioid pain management options sustains reliance on opioids, maintaining demand for OIC treatments like RELISTOR.

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How Has the Competitive Landscape Evolved?

1. Current Competition

Competitor	Drug Name	Formulation	Pricing (Approximate)	Regulatory Status	Notes
RELISTOR	Methylnaltrexone	Injectable, Oral	$400-$600 per dose	Approved (2008, 2015 (oral))	Pioneered for OIC in palliative care
Movantik	Naloxegol	Oral	~$350 per month	FDA-approved (2016)	Oral alternative to RELISTOR
Symproic	Naldemedine	Oral	~$450 per month	FDA-approved (2017)	Higher dosing flexibility
Linzess	Linaclotide	Oral	~$400 per month	Approved for IBS-C & OIC in some countries	Different mechanism, broader indications

2. Emerging Treatments and Pipeline Considerations

• Novel agents exploring non-opioid mechanisms for constipation (e.g., guanylate cyclase-C agonists) may eventually influence market shares.
• Recent developments focus on oral formulations, targeting easier administration and improved patient compliance.

3. Patent and Regulatory Exclusivity

• RELISTOR's initial patents expired in 2018, opening avenues for biosimilars and generics, increasing price competition.
• The Oral RELISTOR received FDA approval in 2019, leading to higher adoption ease but also heightened competition.

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What Are the Regulatory and Payer Influences?

1. Regulatory Decisions and Labeling

• FDA approvals for oral RELISTOR expanded its usability, enhancing market access.
• The European Medicines Agency (EMA) approved it under different labeling parameters, influencing geographic penetration.

2. Payer Reimbursement Policies

Payer Type	Reimbursement Status	Impact
Medicare/Medicaid	Reimburses based on FDA approval	Important for U.S. market
Commercial insurers	Varies by policy	Accessibility depends on formulary listing

• US formulary inclusion is critical; coverage restrictions can limit sales.

3. Price Negotiations and Cost-Effectiveness

• Cost-effectiveness analyses influence formulary decisions.
• Pharmacoeconomic evaluations demonstrate RELISTOR’s value in reducing hospitalizations due to OIC.

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What Are the Financial Trajectories and Projections?

1. Historical Revenue Data

Year	Approximate Revenue (USD Millions)	Comments
2014	$500	Launch phase, expanding indications
2018	$730	Post-patent expiry, price competition easing
2022	$900	Increasing oral formulations absorption

2. Market Growth Projections

Year	Predicted CAGR	Basis for Forecast
2023-2028	4.5%	Rising opioid use, aging population, oral formulations boost demand
2030	$1.2 billion	Continued demographic shifts and expanded indications

3. Drivers of Revenue Growth

• Increased prescribing in hospice and palliative care settings
• Expansion into new geographic markets (Europe, Asia)
• Introduction of biosimilars reducing unit costs

4. Potential Risks to Financial Growth

Risk Factor	Impact	Mitigation Strategies
Patent expiration	Price erosion	Diversification of indications, pipeline expansion
Competition from oral surrogates	Market share decline	Emphasize clinical benefits, patient compliance
Regulatory hurdles	Market access barriers	Engage with authorities early, adaptive labeling

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How Do Regulatory Policies Influence RELISTOR’s Market?

• The FDA’s 2019 approval of oral RELISTOR significantly expanded its usability, leading to increased sales.
• The European Union’s EMA approval in 2020 opened new markets.
• Payer policies favor drugs with demonstrated cost-effectiveness; RELISTOR’s pharmacoeconomic data support favorable reimbursement.

What Are the Key Market Players and Dynamics?

Company	Market Share	Strategic Moves	R&D Focus
Jazz Pharmaceuticals (owner)	~60% since acquisition of Salix (2019)	Investment in oral formulations	Pipeline for broader OIC treatments
Boehringer Ingelheim	Emerging competitor	Focus on biosimilars	Cost reduction strategies
Other generics	Increasing due to patent expiry	Price competition	To enter the market with lower-cost options

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Comparative Analysis of RELISTOR and Competitors

Aspect	RELISTOR	Movantik	Symproic	Linzess
Administration	Injectable, Oral	Oral	Oral	Oral
Indications	OIC in palliative care	OIC	OIC	IBS-C, OIC
Price Range	$400–$600/order	~$350/month	~$450/month	~$400/month
Patent Status	Expired (2018)	Active (2016)	Active (2017)	Active (2009)

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How Do Market Trends Affect RELISTOR’s Future?

• Digital health integration: Telemedicine and electronic prescribing may streamline opioid and OIC management.
• Expanded indications: Investigations into RELISTOR’s efficacy in other gastrointestinal disorders could open new revenue streams.
• Policy shifts: Focus on opioid stewardship may influence prescribing patterns, impacting demand.

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Key Takeaways

• Market growth remains steady due to opioid prevalence, aging demographics, and expanding indications.
• Oral formulations have bolstered accessibility, with FDA approvals in 2019 significantly impacting sales.
• Patent expiries and biosimilar entries threaten price margins but also facilitate broader access.
• Reimbursement policies favor cost-effective treatments, with RELISTOR benefiting from favorable pharmacoeconomic data.
• Competitive landscape intensifies as new agents and generic options emerge, necessitating innovation and strategic positioning.

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Frequently Asked Questions

1. How will patent expirations impact RELISTOR’s revenue?

Patent expirations in 2018 led to increased availability of generic methylnaltrexone, exerting downward pressure on pricing. Although biosimilars are not yet available, entry of generics is expected to reduce revenue margins unless the company diversifies its indications or captures new markets.

2. What role does oral RELISTOR play in the current market?

Approved in 2019, the oral formulation expanded RELISTOR’s use cases, especially outside inpatient settings. It has witnessed faster adoption due to ease of administration, contributing significantly to recent revenue increases.

3. How do regulatory policies influence market access?

Regulatory approvals determine labeling, indications, and reimbursement scope. Harmonized approvals across regions facilitate global distribution; restrictive policies can hinder market penetration.

4. What potential does RELISTOR have in expanding into other indications?

While primarily indicated for OIC, investigational studies assess its efficacy in other gastrointestinal motility disorders, potentially unlocking new revenue streams.

5. How does the competitive environment shape pricing strategies?

Intensity in generic entry and biosimilar development pressures companies to innovate on formulations and indications, affecting pricing. Emphasis on pharmacoeconomics influences payer decisions and reimbursement levels.

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References

1. Centers for Disease Control and Prevention (CDC). 2019 National Prescription Data.
2. Camilleri M. (2018). "Opioid-Induced Constipation." Gastroenterology.
3. United Nations. "World Population Ageing 2020."

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Disclaimer: This analysis synthesizes publicly available data up to 2023 and does not forecast specific financials but provides strategic insights for stakeholders assessing RELISTOR's market landscape.