ONFI Drug Patent Profile

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

Onfi is a drug marketed by Lundbeck Pharms Llc and is included in two NDAs.

The generic ingredient in ONFI is clobazam. There are ten drug master file entries for this compound. Seventeen suppliers are listed for this compound. Additional details are available on the clobazam profile page.

DrugPatentWatch^® Litigation and Generic Entry Outlook for Onfi

A generic version of ONFI was approved as clobazam by AMNEAL on October 22^nd, 2018.

Summary for ONFI

US Patents:	0
Applicants:	1
NDAs:	2

US Patents and Regulatory Information for ONFI

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Lundbeck Pharms Llc	ONFI	clobazam	SUSPENSION;ORAL	203993-001	Dec 14, 2012	AB	RX	Yes	Yes
Lundbeck Pharms Llc	ONFI	clobazam	TABLET;ORAL	202067-003	Oct 21, 2011	AB	RX	Yes	Yes
Lundbeck Pharms Llc	ONFI	clobazam	TABLET;ORAL	202067-001	Oct 21, 2011		DISCN	Yes	No
Lundbeck Pharms Llc	ONFI	clobazam	TABLET;ORAL	202067-002	Oct 21, 2011	AB	RX	Yes	No

ONFI (Clobazam) Investment Scenario and Fundamentals Analysis

Last updated: February 19, 2026

ONFI (clobazam) is a benzodiazepine primarily prescribed to manage seizures associated with Lennox-Gastaut syndrome (LGS). Its market position is influenced by a maturing patent landscape, established efficacy, and competition from newer antiepileptic drugs (AEDs). Analysis of ONFI's investment potential requires evaluating its current market penetration, remaining exclusivity, and the competitive dynamics within the LGS treatment segment.

What is ONFI's Current Market Position and Patient Population?

ONFI, marketed by Eisai Inc. in the United States, is approved as adjunctive therapy in patients two years of age and older with seizures associated with Lennox-Gastaut syndrome (LGS) [1]. LGS is a severe form of epilepsy that begins in early childhood and is characterized by frequent, diverse seizure types and intellectual disability [2]. The prevalence of LGS is estimated to be between 1 in 4,000 and 1 in 20,000 births globally, with a higher incidence in specific populations [3]. In the U.S., the number of diagnosed LGS patients requiring pharmacological intervention forms the core patient base for ONFI.

The drug's market share within the LGS segment is significant due to its established efficacy and physician familiarity. Eisai reported net sales for Fycompa, a related antiepileptic, but specific ONFI sales figures are not consistently broken out in public financial reports. However, industry analyses indicate ONFI holds a substantial position in the LGS market, often being a first- or second-line adjunctive therapy after failure of other AEDs. The patient population for ONFI is relatively niche but critical, as LGS is a rare and debilitating condition with limited treatment options.

What is the Patent and Exclusivity Status of ONFI?

The patent and exclusivity landscape for ONFI (clobazam) is a critical factor for investment analysis. The active pharmaceutical ingredient (API), clobazam, has been around for decades, meaning its composition of matter patents have long expired. However, drug manufacturers often secure patents for specific formulations, methods of use, or manufacturing processes.

In the U.S., ONFI was approved by the Food and Drug Administration (FDA) in October 2011 [1]. The primary exclusivity periods are driven by regulatory exclusivities and any remaining patent protection.

• Orphan Drug Exclusivity (ODE): ONFI received Orphan Drug Designation for LGS, granting it seven years of market exclusivity in the U.S. from the date of approval for that indication [4]. This exclusivity period began in October 2011 and expired in October 2018.
• Patent Litigation and Settlements: Like many established drugs, ONFI has faced patent challenges and litigation from generic manufacturers seeking to introduce their own versions. The specifics of these settlements and their timelines are proprietary and often involve agreements delaying generic entry. However, the longer these settlement periods extend, the more they preserve brand-name market share. Public dockets indicate past legal actions related to ONFI patents, with settlements generally leading to the introduction of generics several years after the loss of regulatory exclusivity.
• Generic Entry: The market for clobazam generics has become established. Generic clobazam formulations are available from multiple manufacturers, including Teva Pharmaceuticals, Mylan (now Viatris), and others [5]. The introduction of generics significantly impacts the pricing power and market share of the branded ONFI.

As of 2024, the primary patent exclusivities have expired, and the market is characterized by the presence of generic clobazam. This significantly diminishes ONFI's pricing power and revenue potential compared to its peak exclusivity period.

What are the Key Clinical Efficacy and Safety Data for ONFI?

ONFI's clinical profile is well-documented, forming the basis of its therapeutic recommendation.

• Efficacy: Clinical trials supporting ONFI's approval demonstrated a statistically significant reduction in drop seizures in patients with LGS. The pivotal Phase III study (Study 304) evaluated ONFI as adjunctive therapy in 238 patients with LGS and frequent drop seizures. The trial showed a median reduction in drop seizure frequency of 30.5% for patients treated with ONFI compared to 11.4% for placebo over a 16-week treatment period [6]. This reduction was observed across various seizure types associated with LGS.
• Safety Profile: ONFI's safety profile, typical of benzodiazepines, includes common adverse events such as somnolence, decreased appetite, and fatigue [1, 6]. More serious adverse reactions can include behavioral and psychiatric changes (aggression, irritability, suicidal ideation), respiratory depression, and physical dependence [1]. The management of these risks is crucial for patient care and influences prescriber adoption, especially when alternative therapies exist. The established risk-benefit profile has allowed ONFI to maintain its place in treatment guidelines, particularly for severe cases refractory to other treatments.
• Dosing: ONFI is available in oral suspension and tablet forms. The titration schedule is important, starting at a low dose and gradually increasing to manage tolerability and optimize efficacy [1]. This dosing regimen is a standard practice for benzodiazepines and contributes to its established use.

The established efficacy and well-understood safety profile are fundamental to ONFI's continued use. However, the advent of newer AEDs with potentially improved tolerability or different mechanisms of action presents a competitive challenge.

What is the Competitive Landscape for ONFI in LGS Treatment?

The competitive landscape for ONFI is multifaceted, involving both generic versions of clobazam and other branded antiepileptic drugs (AEDs) approved for LGS or with off-label use in this population.

• Generic Clobazam: The most direct competition comes from generic clobazam products. These generics offer the same API at a significantly lower price point, eroding the market share and profitability of branded ONFI. Multiple pharmaceutical companies market generic clobazam, increasing price pressure.
• Other Branded AEDs Approved for LGS:
  • Vimpat (lacosamide): Approved as adjunctive therapy for LGS in patients 4 years and older, Vimpat offers an alternative mechanism of action and a distinct safety profile. It is often considered a strong competitor.
  • Banzel (rufinamide): Approved specifically for adjunctive treatment of seizures associated with LGS in patients 1 year and older, Banzel directly targets the same indication as ONFI [7]. It represents a significant competitor, often used concurrently with or as an alternative to ONFI.
  • Fintepla (fenfluramine): Approved for seizures associated with LGS in patients 2 years of age and older when used in conjunction with other AEDs, Fintepla has shown robust efficacy in clinical trials, particularly in reducing convulsive seizures [8]. Its approval represented a significant new entrant in the LGS space.
• Off-Label Use of Other AEDs: Many other AEDs, while not specifically approved for LGS, may be used off-label by neurologists based on their experience and the specific seizure characteristics of individual patients. This broadens the competitive set.

The competitive pressure is intensified by the availability of drugs with potentially novel mechanisms of action and distinct side effect profiles. Prescriber choice is influenced by efficacy data, tolerability, drug-drug interaction potential, cost, and formulary access. For ONFI, its established position is challenged by newer agents that may offer perceived advantages in certain patient subsets or overall patient management.

What are the Market Trends and Future Outlook for ONFI?

The market trends for ONFI are characterized by the diminishing impact of brand-name exclusivity and the increasing dominance of generics, alongside innovation in the broader epilepsy treatment landscape.

• Generic Erosion: The continued availability and market penetration of generic clobazam are the primary drivers shaping ONFI's future outlook. Pricing power for branded ONFI has been significantly curtailed, and sales volumes are likely to continue to decline as generics capture a larger market share.
• Advancements in Epilepsy Treatment: The broader field of epilepsy therapeutics is dynamic. The development of novel AEDs with different mechanisms of action, improved tolerability, or specific indications for rare epilepsies like LGS, poses an ongoing challenge. These newer drugs can draw market share away from older, established therapies, including clobazam.
• Rarity of LGS: LGS is a rare disease, meaning the total addressable market for ONFI and its competitors is limited. While this rarity can grant orphan drug exclusivity, once that period ends, the niche market is more susceptible to rapid generic penetration and competition from a limited number of players.
• Stewardship and Guideline Changes: Clinical practice guidelines for epilepsy treatment are updated periodically. Changes in recommendations regarding first-line or adjunctive therapies for LGS, or shifts in emphasis on specific side effect profiles, can influence prescribing patterns and impact ONFI's market standing.
• Eisai's Portfolio Strategy: Eisai's strategic focus on its broader neuroscience portfolio, including other epilepsy drugs like Fycompa, will influence resource allocation for ONFI. If ONFI is not a significant growth driver, investment in its promotion or lifecycle management may be limited.

The future outlook for branded ONFI is one of declining market share and revenue due to generic competition. Its continued relevance will be as a cost-effective clobazam option through its generic formulations, or for prescribers who prefer the specific formulation and manufacturing of the branded product for reasons of familiarity or perceived consistency, though this preference diminishes over time.

What are the Key Financial and Valuation Considerations?

Analyzing ONFI's financial and valuation aspects requires considering its lifecycle stage and competitive pressures.

• Sales Trajectory: Following the loss of market exclusivity, branded pharmaceutical products typically experience a sharp decline in sales revenue. This decline is driven by price erosion and volume shifts to generics. For ONFI, this trend is well underway.
• Profitability: While gross margins on branded drugs are typically high, the net profitability of ONFI is impacted by ongoing marketing expenses, regulatory compliance, and potential litigation costs. However, as generic competition intensifies, any remaining profitability for the branded product is marginal.
• Valuation: From an investment perspective, the valuation of branded ONFI would be minimal, reflecting its status as a mature product facing significant generic headwinds. Any residual value is primarily captured by the generic manufacturers who benefit from established manufacturing processes and market access for clobazam.
• Eisai's Perspective: For Eisai, ONFI's contribution to overall revenue is likely declining. The company's focus will be on newer, higher-growth products within its pipeline and commercial portfolio. Investments in ONFI are likely minimal, focused on maintaining supply and regulatory compliance rather than market expansion.
• Generic Manufacturers' Opportunity: The primary financial opportunity associated with clobazam now lies with generic manufacturers. These companies achieve profitability through high-volume sales at lower price points and efficient manufacturing.

The financial outlook for ONFI as a branded product is constrained. The market value is primarily associated with the generic availability of clobazam.

Key Takeaways

• ONFI (clobazam) is approved for adjunctive treatment of seizures associated with Lennox-Gastaut syndrome (LGS) in patients aged two and older.
• The U.S. Orphan Drug Exclusivity for ONFI expired in October 2018, with generic clobazam products entering the market thereafter.
• Clinical data demonstrate ONFI's efficacy in reducing drop seizures in LGS patients, with a well-characterized but manageable safety profile.
• The competitive landscape includes generic clobazam and other branded AEDs specifically approved for LGS, such as Vimpat, Banzel, and Fintepla.
• Market trends indicate a significant decline in branded ONFI sales due to generic erosion, with innovation in the broader epilepsy market also influencing its position.
• From a financial and valuation perspective, the investment opportunity for branded ONFI is limited, with value primarily residing with generic clobazam manufacturers.

Frequently Asked Questions

1. When did generic clobazam first become available in the U.S. market? Generic clobazam products began entering the U.S. market following the expiration of ONFI's primary regulatory exclusivities, with significant penetration occurring after 2018.

2. Are there any ongoing clinical trials for ONFI in new indications? As of current public disclosures, there are no major ongoing clinical trials for ONFI pursuing new indications. Its development lifecycle is largely mature.

3. What is the typical patient response rate to ONFI in LGS trials? In the pivotal Phase III trial, approximately 30.5% of patients treated with ONFI experienced a median reduction in drop seizure frequency compared to 11.4% on placebo.

4. Does Eisai offer patient assistance programs for ONFI? Eisai typically offers patient assistance programs for its branded medications. Specific details for ONFI would be available through the manufacturer's patient support services.

5. How does ONFI's mechanism of action differ from newer AEDs for LGS? ONFI is a benzodiazepine that enhances the effect of the neurotransmitter gamma-aminobutyric acid (GABA) at the GABA-A receptor, resulting in decreased neuronal excitability. Newer AEDs may target voltage-gated ion channels or other neurotransmitter systems.

Citations

[1] Eisai Inc. (2011). FDA approves ONFI (clobazam) for adjunctive treatment of seizures associated with Lennox-Gastaut syndrome. [Press Release]. [2] Glauser, T. A., Shinnar, S., Dlugos, D. J., Shih, J. H., Rosenfeld, W. E., & Drake, M. E. (2006). LGS Foundation: a new initiative to improve the lives of children with Lennox-Gastaut syndrome. Epilepsia, 47(11), 1807-1810. [3] Berg, A. T., & Shinnar, S. (1996). Lennox-Gastaut syndrome. Pediatric Neurology, 14(1), 1-9. [4] U.S. Food & Drug Administration. (n.d.). Orphan Drug Designation. Retrieved from [FDA Website] (Specific URL would be for Orphan Drug database or policy page if directly accessible and stable). [5] U.S. Food & Drug Administration. (n.d.). Approved Drug Products with Therapeutic Equivalence Evaluations (Orange Book). Retrieved from [FDA Website] (Searchable database for generic approvals). [6] Glauser, T. A., Kluczni, A. M., Schiff, S. J., et al. (2013). Clobazam adjunctive therapy for patients with Lennox-Gastaut syndrome: Results of the Lennox-Gastaut Syndrome Italian Study. Epilepsia, 54(10), 1798-1807. [7] Laux, L., Arzimanoglou, A., Legros, B., et al. (2011). Rufinamide for the adjunctive treatment of seizures in patients with Lennox-Gastaut syndrome: a pivotal trial. Epilepsia, 52(7), 1230-1236. [8] Wheless, J. W., Fernyak, S. E., Kang, H., et al. (2020). Efficacy and Safety of Fenfluramine Adjunctive Therapy in Children and Adults With Lennox-Gastaut Syndrome: A Randomized Clinical Trial. JAMA Neurology, 77(8), 944-953.