Edaravone (marketed as Radicava®) is a free radical scavenger that was approved for the treatment of amyotrophic lateral sclerosis (ALS) in Japan (2015), South Korea (2018), and the United States (2017). The pivotal trials demonstrated that edaravone can slow functional decline in a subset of ALS patients with early disease and relatively rapid progression[@edaravone2017].
Edaravone represents one of only two FDA-approved disease-modifying therapies for ALS, alongside riluzole, making it a critical treatment option for patients diagnosed with this progressive neurodegenerative disease.
Trial Details
| Parameter | Value | |-----------|-------| | Phase | Phase 3 | | Status | Approved (2017) | | Drug | Edaravone (Radicava®) | | Dosage | 60 mg IV infusion daily | | Patient Population | Adults with ALS | | Treatment Cycle | 28 days on, 28 days off | | ClinicalTrials.gov Identifier | NCT01492686 | | Sponsor | Mitsubishi Tanabe Pharma |
Mechanism of Action
Edaravone works through multiple neuroprotective pathways that address the key pathological mechanisms underlying ALS[@edaravone2019]:
Antioxidant Effects
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Overview
Edaravone (marketed as Radicava®) is a free radical scavenger that was approved for the treatment of amyotrophic lateral sclerosis (ALS) in Japan (2015), South Korea (2018), and the United States (2017). The pivotal trials demonstrated that edaravone can slow functional decline in a subset of ALS patients with early disease and relatively rapid progression[@edaravone2017].
Edaravone represents one of only two FDA-approved disease-modifying therapies for ALS, alongside riluzole, making it a critical treatment option for patients diagnosed with this progressive neurodegenerative disease.
Trial Details
| Parameter | Value | |-----------|-------| | Phase | Phase 3 | | Status | Approved (2017) | | Drug | Edaravone (Radicava®) | | Dosage | 60 mg IV infusion daily | | Patient Population | Adults with ALS | | Treatment Cycle | 28 days on, 28 days off | | ClinicalTrials.gov Identifier | NCT01492686 | | Sponsor | Mitsubishi Tanabe Pharma |
Mechanism of Action
Edaravone works through multiple neuroprotective pathways that address the key pathological mechanisms underlying ALS[@edaravone2019]:
Antioxidant Effects
Free Radical Scavenging: Edaravone directly neutralizes peroxyl radicals and other reactive oxygen species that accumulate in ALS patients
Oxidative Stress Reduction: Reduces overall oxidative burden in motor neurons
Neuroinflammation Modulation: Attenuates inflammatory responses that contribute to neurodegeneration
Neuroprotective Mechanisms
Neuronal Survival: Protects motor neurons from oxidative damage-induced death
Axonal Integrity: Preserves axonal structure and function
Mitochondrial Protection: Helps maintain mitochondrial function under oxidative stress
Protein Aggregation Reduction: May reduce formation of aberrant protein aggregates
Cellular Protection
The drug's ability to cross the blood-brain barrier allows it to directly protect motor neurons in the central nervous system. Research suggests edaravone may work through:
Upregulation of neurotrophic factors
Inhibition of inducible nitric oxide synthase (iNOS)
Reduction of caspase-3 activation
Modulation of the Nrf2-ARE pathway
Clinical Trial Program
Pivotal Studies
The clinical development program included multiple randomized, double-blind, placebo-controlled trials:
MCI-186-1 (Japanese Confirmatory Trial)
Design: 24-week treatment period
Population: 137 ALS patients
Primary Endpoint: Change in ALSFRS-R score
Result: Significant benefit in functional decline
MCI-186-2 (US Trial)
Design: 24-week treatment
Population: Similar to Japanese trial
Result: Mixed results, led to post-hoc analysis
Post-hoc Analysis
A critical post-hoc analysis identified a subgroup of patients who showed the strongest response to edaravone:
Disease duration ≤ 2 years
Forced vital capacity (FVC) ≥ 80%
Definite or probable ALS by El Escorial criteria
This analysis formed the basis for the FDA's indication, which specifies treatment for "patients with ALS."
Results
Key Findings
Functional Decline: 33% slower progression in treated patients vs placebo[@edaravone2017]
Response Rate: Most pronounced benefit in early, rapidly progressing patients