CEREBYX Drug Patent Profile

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

Cerebyx is a drug marketed by Parke Davis and is included in one NDA.

The generic ingredient in CEREBYX is fosphenytoin sodium. There are eight drug master file entries for this compound. Eight suppliers are listed for this compound. Additional details are available on the fosphenytoin sodium profile page.

DrugPatentWatch^® Litigation and Generic Entry Outlook for Cerebyx

A generic version of CEREBYX was approved as fosphenytoin sodium by FRESENIUS KABI USA on August 6^th, 2007.

Summary for CEREBYX

US Patents:	0
Applicants:	1
NDAs:	1
Finished Product Suppliers / Packagers:	1
Raw Ingredient (Bulk) Api Vendors:	78
Clinical Trials:	1
Patent Applications:	3,247
Drug Prices:	Drug price information for CEREBYX
What excipients (inactive ingredients) are in CEREBYX?	CEREBYX excipients list
DailyMed Link:	CEREBYX at DailyMed

See drug prices for CEREBYX

Recent Clinical Trials for CEREBYX

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

Sponsor	Phase
Emory University	Phase 4
UCB Pharma	Phase 4

See all CEREBYX clinical trials

Pharmacology for CEREBYX

Drug Class	Anti-epileptic Agent
Mechanism of Action	Cytochrome P450 1A2 Inducers Cytochrome P450 2B6 Inducers Cytochrome P450 2C19 Inducers Cytochrome P450 2C8 Inducers Cytochrome P450 2C9 Inducers Cytochrome P450 2D6 Inducers Cytochrome P450 3A Inducers
Physiological Effect	Decreased Central Nervous System Disorganized Electrical Activity

US Patents and Regulatory Information for CEREBYX

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Parke Davis	CEREBYX	fosphenytoin sodium	INJECTABLE;INJECTION	020450-001	Aug 5, 1996	AP	RX	Yes	Yes

Expired US Patents for CEREBYX

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	Patent No.	Patent Expiration
Parke Davis	CEREBYX	fosphenytoin sodium	INJECTABLE;INJECTION	020450-001	Aug 5, 1996	4,260,769
Parke Davis	CEREBYX	fosphenytoin sodium	INJECTABLE;INJECTION	020450-001	Aug 5, 1996	4,925,860

International Patents for CEREBYX

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

Country	Patent Number	Title	Estimated Expiration
Austria	135907
Australia	5670490
Australia	632130
Canada	2067122

Supplementary Protection Certificates for CEREBYX

Patent Number	Supplementary Protection Certificate	SPC Country	SPC Expiration	SPC Description
0145340	99C0005	Belgium		PRODUCT NAME: FOSPHENYTOIN DISODIUM; NAT. REGISTRATION NO/DATE: NL 23 613 19980806; FIRST REGISTRATION: GB - PL 000 19/0157 19980204
0473687	SPC/GB98/030	United Kingdom		PRODUCT NAME: FOSPHENYTOIN SODIUM (3-HYDROXYMETHYL)-5,5-DIPHENYLHYDANTOIN DISODIUM PHOSPHATE ESTER); REGISTERED: UK 0019/0157 19980204
0473687	99C0008	Belgium		PRODUCT NAME: FOSPHENYTOINUM DINATRICUM; REGISTRATION NO/DATE: 19 IS 102 F12 19980901; FIRST REGISTRATION: GB PL00019/1057 19980204
0473687	C980045	Netherlands		PRODUCT NAME: FOSPHENYTOINUM-DI-NATRICUM; NATL REGISTRATION NO/DATE: RVG 22758 19980702; FIRST REGISTRATION: GB PL 00019/0157 19980204

Last updated: June 12, 2026

CEREBYX (fosphenytoin) market dynamics and financial trajectory: pricing, demand drivers, exclusivity cliff, and competitive threats

CEREBYX (fosphenytoin) is a legacy anti-seizure injectable sold in a mature, largely generic-exposed market. Its commercial trajectory tracks (1) hospital inpatient use for status epilepticus and acute seizure management, (2) substitution risk versus generic phenytoin sodium injection and ready-to-use alternatives, and (3) cyclic pricing compression typical for older sterile injectables. From an exclusivity and patent perspective, the near-term market outlook is dominated by availability and competitive pricing rather than sustained brand differentiation, with revenue largely determined by distributor inventory, formulary access, and contract pricing.

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What is CEREBYX and how is it used in hospitals?

CEREBYX is the prodrug of phenytoin supplied as a sterile injection for patients who need parenteral antiepileptic therapy when oral administration is not possible. Clinically, its pull is driven by emergency and inpatient pathways where neurology and emergency medicine protocols require rapid IV antiepileptic options.

Key clinical use-cases that influence pull-through

• Status epilepticus and acute convulsive seizures in the emergency department and ICU.
• Conversion therapy when patients cannot take oral antiseizure medication.
• Situational use where prescribers prefer the IV fosphenytoin formulation over legacy IV phenytoin sodium, often tied to tolerability and infusion-rate handling in practice.

Where demand is concentrated

Demand is concentrated in:

• Large hospital systems with established neurology protocols.
• Contract purchasing environments where sterile injectables are priced competitively at renewal.
• Pharmacy and therapeutics committees that decide formulary placement for IV antiseizure drugs.

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How has CEREBYX performed financially versus older phenytoin injectables?

CEREBYX competes primarily against older, widely available phenytoin sodium injection products and other IV antiseizure injectables used in acute seizure settings. In mature sterile markets, brand revenue is sensitive to:

• Unit price compression after generic entry.
• Switching from branded prodrug to cheaper generics without clear differentiation in formularies.
• Contract tendering and volume rebates that favor the lowest-cost equivalent.

What typically drives brand sales in this segment

• Hospital protocol adherence: if an institution starts status epilepticus algorithms with fosphenytoin, volume is sticky.
• Short shortages and supply continuity: sterile supply interruptions can temporarily support pricing and brand visibility.
• Purchase cycles: major system contract renewals can trigger step-changes in share.

What typically harms brand sales

• Generic substitution pressure after any incremental competitive approvals.
• Competitive contracting: pharmacy buyers use multiple bid rounds and therapeutic interchange to reduce spend.
• Tender-driven switching to phenytoin sodium and other IV alternatives when clinical teams accept equivalence.

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What patents protect CEREBYX and how strong is the patent estate?

This section is not available with sufficient precision because specific, active CEREBYX patent numbers, assignees, and expiration dates are not provided in the input. Without those hard data, no complete and accurate patent-strength assessment can be produced.

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When does CEREBYX lose exclusivity, and what is the likely generic entry window?

This section is not available with sufficient precision because exclusivity loss dates and applicable regulatory exclusivities tied to CEREBYX (including Orange Book exclusivity periods, if any) are not provided in the input. Without those hard dates, no complete exclusivity timeline can be produced.

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What is the Orange Book status of CEREBYX, and which exclusivities matter for generics?

This section is not available with sufficient precision because Orange Book listings for CEREBYX (application numbers, listed patents, exclusivity codes, and expiration dates) are not provided in the input. Without that data, no accurate Orange Book status can be produced.

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What patent litigation affects CEREBYX and what settlements changed competition?

This section is not available with sufficient precision because CEREBYX-specific Paragraph IV, litigation dockets, or settlement terms are not provided in the input. Without those hard litigation records, no reliable litigation impact assessment can be produced.

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How does CEREBYX compare with phenytoin sodium injection and other acute IV antiseizure options?

CEREBYX is a prodrug that converts to phenytoin and is used where rapid IV antiepileptic coverage is needed. In market dynamics, the effective competitive set usually includes:

• Generic phenytoin sodium injection (direct alternative in acute seizure management).
• Other IV antiseizure therapies used in status epilepticus protocols (depending on guideline adoption and formulary preference).

Commercial substitution dynamics

• If formularies treat parenteral phenytoin options as interchangeable, CEREBYX share is vulnerable once generic phenytoin pricing undercuts it.
• If clinical preference favors fosphenytoin infusion handling, share is more resilient but still exposed to contract pricing pressure in mature tenders.

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What formulations and strengths drive CEREBYX procurement and contracting?

This section is not available with sufficient precision because the input does not include the specific CEREBYX presentation details (strengths, packaging, NDCs, and whether multiple SKUs exist in active distribution), which are required to map procurement and contracting levers.

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Which companies compete with CEREBYX for hospital IV antiseizure demand?

This section is not available with sufficient precision because competitor product identities and NDC-level market participation are not provided in the input. Without specific competitors and product mapping, no accurate competitive landscape can be produced.

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What generic entry risks exist for CEREBYX and how would launch scenarios affect revenue?

This section is not available with sufficient precision because the input does not provide:

• Orange Book patent and exclusivity barriers,
• likely legal status,
• or the specific regulatory posture (e.g., ANDA timing, 505(b)(2) pathways), so no credible generic launch scenario can be constructed.

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How does CEREBYX’s pricing trend interact with hospital budgets and rebate structures?

In mature hospital injectables, revenue is typically driven more by contracting outcomes than by list-price behavior. For CEREBYX, the controlling commercial mechanics are:

• Group purchasing organization (GPO) and IDN formulary outcomes.
• Distributor purchasing and inventory management.
• Contract pricing at renewal for high-volume SKUs.
• Hospital substitution behavior during outages or shortages.

Expected financial pattern for a legacy injectable brand

• Steady-to-declining unit share over time as generics and therapeutically interchangeable drugs gain formulary access.
• Revenue volatility tied to supply chain disruptions or procurement re-bids.
• Margin compression over time as competitive pricing becomes the dominant driver.

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What is the revenue exposure to substitution versus alternative therapies?

This section is not available with sufficient precision because the input does not include:

• historic CEREBYX revenue or unit volume,
• market share metrics,
• or contracting share by customer segment, so no quantified revenue exposure can be produced.

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Key Takeaways

• CEREBYX is a mature, inpatient-focused anti-seizure injectable whose market dynamics are shaped primarily by hospital formulary placement and procurement contracting rather than by sustained differentiation.
• Competitive substitution risk is structurally high versus generic phenytoin sodium injection and other IV acute antiseizure options used in status epilepticus protocols.
• Financial trajectory is expected to follow legacy injectable patterns: pricing and share compression over time with periodic volatility tied to supply and contract cycles.
• A patent, Orange Book, and litigation-based exclusivity outlook cannot be completed from the provided input because the necessary hard listing and docket data are not included.

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FAQs

1. Does CEREBYX have therapeutic interchange risk versus generic phenytoin sodium injection in hospital formularies?
2. How do GPO contracts and IDN tender cycles typically impact revenue for legacy sterile injectable brands like CEREBYX?
3. What acute seizure guidelines most influence IV antiseizure ordering patterns that drive CEREBYX use?
4. How do sterile supply disruptions and allocation policies affect short-term market share for CEREBYX?
5. What regulatory pathway and patent listing structures usually govern generic entry for IV legacy injectables like CEREBYX?

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References

1. (No cited sources available from the provided input.)