TheraRadar
Data updated: May 26, 2026

SYMPAZAN (clobazam)

Cytochrome P450 2D6 Inhibitors Trial Activity: Declining
CNS Approved 2018-11-01

SYMPAZAN (clobazam) is a benzodiazepine indicated for the adjunctive treatment of seizures associated with Lennox-Gastaut Syndrome (LGS). The medication is approved for use in both pediatric and adult patients 2 years of age or older. It is utilized as a supplemental therapy to help manage the seizure activity characteristic of this condition.

Source: FDA Label • ASSERTIO SPECLTY • Benzodiazepine

How SYMPAZAN Works

SYMPAZAN is a 1,5-benzodiazepine that targets the GABA A receptor within the central nervous system. While the exact mechanism is not fully understood, the drug is thought to bind to the benzodiazepine site of the receptor to potentiate GABAergic neurotransmission. This process enhances inhibitory signaling, which is believed to be responsible for its therapeutic effect.

Development Insights

Jazz Pharmaceuticals conducting 2 trials (20%)
13 indications explored (Broad Platform)
epilepsy (4 trials)
dravet syndrome (2 trials)
anxiety (1 trials)
1
Indication
--
Phase 3 Trials
7
Years on Market

Details

Status
Prescription
First Approved
2018-11-01
Patent Cliff
2040

Pro Metrics

Patent cliff and revenue data

Unlock with Pro
Routes
ORAL
Dosage Forms
FILM

Companies

Active Ingredient: CLOBAZAM

SYMPAZAN Approval History

2019
2020
2021
2022
2023
2024
2025
2026
Original
New Indication
New Form
Label Update
18 FDA actions from 2018 to 2024
Mar 2024 SUPPL
Label · Labeling
Jan 2023 SUPPL
Label · Labeling
Mar 2021 SUPPL
Label · Labeling

What SYMPAZAN Treats

2 indications

SYMPAZAN is approved for 2 conditions since its original approval in 2018. These indications span multiple therapeutic areas including oncology, immunology, and more.

  • Seizures
  • Lennox-Gastaut Syndrome
Source: FDA Label

SYMPAZAN Boxed Warning

RISKS FROM CONCOMITANT USE WITH OPIOIDS ; ABUSE, MISUSE, AND ADDICTION; and DEPENDENCE AND WITHDRAWAL REACTIONS Concomitant use of benzodiazepines and opioids may result in profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing of these drugs in patients for whom alternative treatment options are inadequate. Limit dosages and durations to the minimum required. Follow patients for signs and symptoms of respiratory depression and sedation [see Warnings and Prec...

SYMPAZAN Competitive Set

Pro

Three rings of competition based on shared molecular targets and treated indications.

Unlock 16 more competitors across all three rings.
Upgrade to Pro

Filters applied: drops same-active-ingredient (505(b)(2) reformulations), route-mismatch (topical vs systemic), and cross-therapeutic-area matches in same-indication rings.

Drugs Similar to SYMPAZAN

3 of 20

FDA-approved drugs for similar conditions. Compare mechanisms and indications to understand treatment alternatives.

BANZEL
RUFINAMIDE
2 shared
EISAI INC
Shared indications:
EPIDIOLEX
CANNABIDIOL
2 shared
JAZZ PHARMS RES
Shared indications:
FENFLURAMINE
FENFLURAMINE
2 shared
Apotex
Shared indications:
📋

Clinical Trial Registry

10 trials
Trial Sponsor ID Phase Status Title
NCT02565108 results posted GWEP1428 Blinded Phase 2014-002942-33 Ph 2 completed A Randomized Controlled Trial to Investigate Possible Drug-drug Interactions Between Clobazam and Cannabidiol
NCT02564952 results posted GWEP1428 Open-Label Extension 2014-002942-33 Ph 2 completed An Open-label Extension Study to Investigate Possible Drug-drug Interactions Between Clobazam and Cannabidiol
NCT03371836 results posted onfi90037 Ph 4 completed Use of Clobazam for Epilepsy and Anxiety
NCT02134366 EPC-1 Ph 3 terminated Clobazam Use in Epilepsia Partialis Continua - Pilot Study
NCT02374567 GAP GAP-2014 Ph 3 terminated Pharmacovigilance in Gerontopsychiatric Patients
NCT02187809 results posted 14362B Ph 3 terminated Safety and Tolerability of Clobazam as Adjunctive Therapy in Paediatric Patients Aged ≥1 to ≤16 Years With Dravet Syndrome
NCT01179828 Predictio KEK 213/09 grant: SPUM no. 33CM30_124117 Ph 3 completed Linking Altered Central Pain Processing and Genetic Polymorphism to Drug Efficacy in Chronic Low Back Pain (Predictio)
NCT02174094 14362A Ph 3 withdrawn Clobazam as Adjunctive Therapy in Paediatric Patients Aged ≥1 to ≤16 Years With Dravet Syndrome
NCT01291316 GABA-SPUM Ph 1, Ph 2 completed GABAergic Modulation in Pain Transmission in Human: Effect of the GABAA Agonist Clobazam on Peripheral and Central Sensitisation
NCT01011036 152/09 SNF SPUM no.33CM30_124117 Ph 3 completed Effects of GABA-a-Agonists on Pain Mechanisms: An Experimental Study in Healthy Volunteers
🔬

Active Pipeline

Pro

Ongoing clinical trials by development phase

Loading...

Key Completed Trials

Pro

Completed studies with published results, ranked by significance

Loading...
📊

Trial Timeline

Full development history with FDA approval milestones

|
Loading...
Understanding FDA Approval Types
Count Type What it means
- ORIG Original approval - drug first enters market
- SUPPL - Efficacy New indication (new disease/condition approved)
- SUPPL - Labeling Label text changes (warnings, dosing updates)
- SUPPL - Manufacturing Production changes (new facility)
- SUPPL - Chemistry Formulation changes (new dosage strength)

Green lines in the timeline show ORIG and Efficacy approvals - the clinically meaningful milestones.

SYMPAZAN FDA Label Details

Indications & Usage

FDA Label (PDF)

SYMPAZAN is indicated for the treatment of Seizures; Lennox-Gastaut Syndrome.

⚠️ BOXED WARNING

WARNING: RISKS FROM CONCOMITANT USE WITH OPIOIDS ; ABUSE, MISUSE, AND ADDICTION; and DEPENDENCE AND WITHDRAWAL REACTIONS Concomitant use of benzodiazepines and opioids may result in profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing of these drugs in patients...

View full patent landscape →
3 OB patents · 1 families · 17 international docs across 7 countries

SYMPAZAN Patents & Exclusivity

Latest Patent: Jan 2040

Patents (3 active)

US11541002 Expires Jan 31, 2040
US12403090 Expires Sep 5, 2039
US12290597 Expires Sep 5, 2039
Source: FDA Orange Book

Pro Intelligence Preview

Deep insights for SYMPAZAN

Revenue Insights

  • Quarterly revenue tracking
  • Historical trend analysis

Patent Timeline

  • Cliff: 2040
  • 21 active patents

Trial Analysis

  • 10 total trials
  • Stage: Declining

Competitive Landscape

  • 20 similar drugs
  • Same target/indication analysis
Unlock Full Intelligence

Full approval history • All patents • Revenue trends • Competitor analysis

Data Sources

Data sourced from official FDA and NIH databases. Click links to verify on original sources.

How We Calculate These Metrics

Trial Activity Stage

Measures the current development activity pattern based on trial phases, status, and trends. Important: This measures R&D activity, not commercial lifecycle.

Trial statuses: "Active" means recruiting or ongoing. "Completed" means reached planned endpoint. "Terminated" means stopped early—often due to safety, efficacy, or business reasons.

  • Growth: High proportion of early-phase trials (Phase 1/2), active development
  • Expansion: Significant Phase 3 activity, approaching or pursuing approvals
  • Mature: Substantial Phase 4 post-marketing studies
  • Stable: Mixed phase distribution, steady development
  • Declining: Low active trial ratio, reduced R&D investment