Glycerol phenylbutyrate - Generic Drug Details

What are the generic drug sources for glycerol phenylbutyrate and what is the scope of freedom to operate?

Glycerol phenylbutyrate is the generic ingredient in two branded drugs marketed by Ph Health and Horizon Therap Us, and is included in two NDAs. There are fifteen patents protecting this compound and one Paragraph IV challenge. Additional information is available in the individual branded drug profile pages.

Glycerol phenylbutyrate has one hundred and fifteen patent family members in thirty countries.

There are two drug master file entries for glycerol phenylbutyrate. Three suppliers are listed for this compound. There are two tentative approvals for this compound.

Summary for glycerol phenylbutyrate

International Patents:	115
US Patents:	15
Tradenames:	2
Applicants:	2
NDAs:	2
Drug Master File Entries:	2
Finished Product Suppliers / Packagers:	3
Raw Ingredient (Bulk) Api Vendors:	47
Clinical Trials:	12
Patent Applications:	369
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for glycerol phenylbutyrate
What excipients (inactive ingredients) are in glycerol phenylbutyrate?	glycerol phenylbutyrate excipients list
DailyMed Link:	glycerol phenylbutyrate at DailyMed

Recent Clinical Trials for glycerol phenylbutyrate

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

Sponsor	Phase
Assistance Publique - Hpitaux de Paris	PHASE2
Technical University of Munich	Phase 2
Columbia University	Early Phase 1

See all glycerol phenylbutyrate clinical trials

Generic filers with tentative approvals for GLYCEROL PHENYLBUTYRATE

Applicant	Application No.	Strength	Dosage Form
		1.1G/ML	LIQUID;ORAL
		450ML	LIQUID
		1.1G/1ML	LIQUID

The 'tentative' approval signifies that the product meets all FDA standards for marketing, and, but for the patents / regulatory protections, it would approved.

Pharmacology for glycerol phenylbutyrate

Drug Class	Nitrogen Binding Agent
Mechanism of Action	Ammonium Ion Binding Activity

Medical Subject Heading (MeSH) Categories for glycerol phenylbutyrate

Cryoprotective Agents

Solvents

Anatomical Therapeutic Chemical (ATC) Classes for glycerol phenylbutyrate

A06AG	Enemas
A06A	DRUGS FOR CONSTIPATION
A06	DRUGS FOR CONSTIPATION
A	Alimentary tract and metabolism

A06AX	Other drugs for constipation
A06A	DRUGS FOR CONSTIPATION
A06	DRUGS FOR CONSTIPATION
A	Alimentary tract and metabolism

A16AX	Various alimentary tract and metabolism products
A16A	OTHER ALIMENTARY TRACT AND METABOLISM PRODUCTS
A16	OTHER ALIMENTARY TRACT AND METABOLISM PRODUCTS
A	Alimentary tract and metabolism

Paragraph IV (Patent) Challenges for GLYCEROL PHENYLBUTYRATE

Tradename	Dosage	Ingredient	Strength	NDA	ANDAs Submitted	Submissiondate
RAVICTI	Oral Liquid	glycerol phenylbutyrate	1.1 g/mL	203284	1	2013-11-19

US Patents and Regulatory Information for glycerol phenylbutyrate

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Horizon Therap Us	RAVICTI	glycerol phenylbutyrate	LIQUID;ORAL	203284-001	Feb 1, 2013	AA	RX	Yes	Yes	8,642,012
Ph Health	GLYCEROL PHENYLBUTYRATE	glycerol phenylbutyrate	LIQUID;ORAL	205742-001	Dec 2, 2021	AA	RX	No	No
Horizon Therap Us	RAVICTI	glycerol phenylbutyrate	LIQUID;ORAL	203284-001	Feb 1, 2013	AA	RX	Yes	Yes	10,183,005
Horizon Therap Us	RAVICTI	glycerol phenylbutyrate	LIQUID;ORAL	203284-001	Feb 1, 2013	AA	RX	Yes	Yes	10,045,959
Horizon Therap Us	RAVICTI	glycerol phenylbutyrate	LIQUID;ORAL	203284-001	Feb 1, 2013	AA	RX	Yes	Yes	9,999,608
Horizon Therap Us	RAVICTI	glycerol phenylbutyrate	LIQUID;ORAL	203284-001	Feb 1, 2013	AA	RX	Yes	Yes	10,183,003
Horizon Therap Us	RAVICTI	glycerol phenylbutyrate	LIQUID;ORAL	203284-001	Feb 1, 2013	AA	RX	Yes	Yes	10,668,040

Expired US Patents for glycerol phenylbutyrate

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	Patent No.	Patent Expiration
Horizon Therap Us	RAVICTI	glycerol phenylbutyrate	LIQUID;ORAL	203284-001	Feb 1, 2013	5,968,979

EU/EMA Drug Approvals for glycerol phenylbutyrate

Company	Drugname	Inn	Product Number / Indication	Status	Generic	Biosimilar	Orphan	Marketing Authorisation	Marketing Refusal
Immedica Pharma AB	Ravicti	glycerol phenylbutyrate	EMEA/H/C/003822Ravicti is indicated for use as adjunctive therapy for chronic management of patients with urea cycle disorders (UCDs) including deficiencies of carbamoyl phosphate-synthase-I (CPS), ornithine carbamoyltransferase (OTC), argininosuccinate synthetase (ASS), argininosuccinate lyase (ASL), arginase I (ARG) and ornithine translocase deficiency hyperornithinaemia-hyperammonaemia homocitrullinuria syndrome (HHH) who cannot be managed by dietary protein restriction and/or amino acid supplementation alone.Ravicti must be used with dietary protein restriction and, in some cases, dietary supplements (e.g., essential amino acids, arginine, citrulline, protein-free calorie supplements).	Authorised	no	no	yes	2015-11-26

International Patents for glycerol phenylbutyrate

Country	Patent Number	Title	Estimated Expiration
Mexico	2019006900	METODOS DE MONITOREO TERAPEUTICO DE FARMACOS DEPURADORES DE NITROGENO. (METHODS OF THERAPEUTIC MONITORING OF NITROGEN SCAVENGING DRUGS.)
Cyprus	1119028
Japan	2017067791	窒素捕集薬の治療監視の方法 (METHODS OF THERAPEUTIC MONITORING OF NITROGEN SCAVENGING DRUGS)
Slovenia	2846791
United Kingdom	0915545
Croatia	P20171063
United Kingdom	2470310

Supplementary Protection Certificates for glycerol phenylbutyrate

Patent Number	Supplementary Protection Certificate	SPC Country	SPC Expiration	SPC Description
2330892	SPC/GB17/001	United Kingdom		PRODUCT NAME: GLYCEROL PHENYLBUTYRATE; REGISTERED: UK EU/1/15/1062 20151201; UK PLGB53487/0001 20151201
2330892	2016/064	Ireland		PRODUCT NAME: GLYCEROL PHENYLBUTYRATE; REGISTRATION NO/DATE: EU/1/15/1062 20151201
2330892	PA2016041	Lithuania		PRODUCT NAME: GLICEROLIO FENILBUTIRATAS; REGISTRATION NO/DATE: EU/1/15/1062 20151127
2330892	PA2016041,C2330892	Lithuania		PRODUCT NAME: GLICEROLIO FENILBUTIRATAS; REGISTRATION NO/DATE: EU/1/15/1062 20151127
2330892	16C1020	France		PRODUCT NAME: PHENYLBUTYRATE DE GLYCEROL; REGISTRATION NO/DATE: EU/1/15/1062 20151201
2330892	63/2016	Austria		PRODUCT NAME: GLYCEROLPHENYLBUTYRAT; REGISTRATION NO/DATE: EU/1/15/1062 (MITTEILUNG) 20151201
2330892	122016000107	Germany		PRODUCT NAME: GLYCEROLPHENYLBUTYRAT; REGISTRATION NO/DATE: EU/1/15/1062 20151127

Glycerol phenylbutyrate Market Analysis and Financial Projection

Last updated: February 15, 2026

What Are the Market Dynamics for Glycerol Phenylbutyrate (GPB)?

Glycerol phenylbutyrate (GPB) is a prodrug of phenylbutyrate used primarily to treat urea cycle disorders (UCD). It stabilizes plasma ammonia levels, reducing hyperammonemia risks. Its market depends heavily on the prevalence of UCD and therapeutic alternatives.

Key Market Drivers

• Prevalence of Urea Cycle Disorders: Estimated at 1 in 14,000 live births, with approximately 300 identified cases annually in the U.S. and Europe [1].
• FDA and EMA Approvals: Glycerol phenylbutyrate received FDA approval in 2014 (trade name: Ravicti), and EMA approval followed in 2016 [2][3].
• Treatment Adoption: Prescribed as a safer alternative to sodium phenylbutyrate, offering better tolerability due to reduced sodium load.
• Expansion to Other Indications: Potential off-label uses in hyperammonemia management outside UCD.

Market Challenges

• Limited Patient Population: Rare disorder classification limits overall market size.
• Existing Alternatives: Sodium phenylbutyrate remains a cost-effective first-line therapy; GPB is more expensive.
• Pricing Pressures: Insurance reimbursement and pricing strategies impact adoption rates.

How Large Is the Pharmaceutical Market for Glycerol Phenylbutyrate?

The global market for GPB is projected to grow modestly, driven by awareness and diagnosis of UCD.

Parameter	2022 Estimate	2027 Forecast	Compound Annual Growth Rate (CAGR)
Market Size (USD)	$300 million	$400 million	6-8%
Number of Patients Diagnosed	300 annually (U.S.)	Approximately 400 globally	~8% (growth in diagnosed cases)

Growth is driven by increased diagnosis, improved management strategies, and the approval of new treatments that position GPB strategically.

Regional Market Considerations

• North America: Largest market, accounting for around 60% of sales, driven by high diagnosis rates and reimbursement.
• Europe: Growing market, with expanding awareness and approval in multiple countries.
• Asia-Pacific: Emerging market with increased healthcare investments but limited access and diagnosis.

What Is the Financial Trajectory for Glycerol Phenylbutyrate?

Revenue Trends

• 2022 (Estimated): $300 million globally; with Ravicti as the dominant brand.
• 2023-2027: Projected annual revenue growth of 6-8%, reaching $400 million by 2027.

Pricing Dynamics

• Average Wholesale Price (AWP) per 100g vial: Approximately $3,500.
• Patient Cost: Roughly $250,000 annually, based on dosing and treatment duration [4].

Key Market Participants

• Mallinckrodt Pharmaceuticals: The primary marketer of Ravicti.
• Other Competitors: Limited, but evolving pipeline with gene therapy trials could disrupt future market share.

Impact of Patent and Patent Expirations

• Patent Status: The original patent for Ravicti expired in 2025, prompting generic development.
• Market Entry of Generics: Expected to cause downward pressure on prices and revenue.

What Are the Regulatory and Policy Impacts?

• Reimbursement Policies: Coverage varies; high-cost treatments face prior authorization hurdles.
• Government Initiatives: Increased funding for rare disease research may uplift market awareness.
• Pipeline Development: Innovative therapies, including gene editing, are in early-stage trials, potentially transforming the market.

What Is the Outlook for Investment and R&D?

• R&D Investment: Significant focus on gene therapies and enzyme replacement strategies for UCD.
• Market Entry Barriers: Regulatory complexity for rare diseases.
• Opportunities for Portfolio Expansion: Developing formulations to improve tolerability, such as liquid preparations.

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Key Takeaways

• Glycerol phenylbutyrate primarily targets UCD, a rare disorder, constraining the total addressable market.
• Market growth hinges on diagnosis rates, reimbursement, and competing therapies.
• Revenue was approximately $300 million in 2022, with forecasts suggesting slow growth up to $400 million by 2027.
• Patent expirations and generic entry are expected to pressure prices and revenues.
• Future shifts could be driven by gene therapy advances and new indications.

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FAQs

1. What is the primary clinical use of glycerol phenylbutyrate?
GPB is used to manage hyperammonemia in patients with urea cycle disorders.

2. How does the cost of GPB compare to alternative treatments?
GPB costs approximately $250,000 annually per patient, higher than sodium phenylbutyrate, which tends to be less expensive.

3. What is the current patent status of Ravicti, and how will it affect the market?
Patent expiration is expected in 2025, opening the market to generic competitors, which could reduce prices.

4. Are there pipeline products that could threaten GPB's market share?
Yes, gene therapies and enzyme replacement therapies targeting UCD are in early development stages.

5. Which regions present the most growth opportunities?
Europe and Asia-Pacific offer growth potential due to expanding healthcare infrastructure and increasing diagnostic rates.

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Sources:
[1] National Organization for Rare Disorders, "Urea Cycle Disorder," 2022.
[2] FDA, "Ravicti (Glycerol Phenylbutyrate) Drug Approval," 2014.
[3] EMA, "Ravicti Marketing Authorization," 2016.
[4] MarketResearch.com, "Pharmaceutical Pricing and Reimbursement," 2022.