What does the drug do?

Edaravone was originally developed to treat acute ischemic stroke, however it was then tested in people with MND. One theory about why motor neurones die in MND is that they are affected by oxidative stress. Cell’s normal metabolic processes can cause oxidative stress. This can result in cellular damage resulting in excessive accumulation of free radiations. Edaravone acts as a ‘free radical scavenger’ helping to reduce the effects of oxidative stress and hopefully slow the progression of MND.

Two different formulations of edaravone have been made, including an intravenous (straight into the bloodstream) formulation and an oral form.

Trial Outcome 

Treatment with Edaravone has showed some signs of beneficial effect in clinical trials. Other trials are underway, which are looking to see the impact Edaravone has on markers of the disease within the body (biomarkers). You can read more here.

Both Oral and Intravenous Edaravone (Radicava) has been approved as a treatment of ALS in the USA and a select few other countries. Radicava was reviewed by the European Medicines Agency (EMA) but Mitsubishi Tanabe Pharma America withdrew the application. At the time of the withdrawal, the Committee for Medicinal Products for Human Use, of the EMA, was trending towards not approving Radicava. You can read some FAQs about the withdrawal here.

A different formulation of Oral Edaravone is being tested in a clinical trial across Europe. You can find out more about this trial here.

Previous Clinical Trials

Phase 3 (intravenous formulation)

The first Phase 3 clinical trial was for an intravenous formulation (straight into the bloodstream) of edaravone (Radicava). It was found to provide no overall benefit in people with MND, but showed an improvement in breathing function in a subgroup of people with an early form of the disease. Two studies have been conducted in this subgroup of patients. Results of the second study, announced at the 27th International Symposium on ALS/MND in 2016, revealed that after 24-week intervention patients showed some signs of beneficial effect. It has been estimated that approximately 7% of people with MND were eligible to take part in the clinical trials, showing improvement in only a small amount of people.

Edaravone (Radicava) is currently available in Japan, South Korea, the U.S, Canada, Switzerland, and China.

Phase 3

The Phase 3 clinical trial testing an oral suspension formulation of edaravone (MT-1186) was launched in November 2019, but was paused in March 2020 due to the COVID-19 pandemic. The trial recruited 185 participants between 18 to 75 years. Interim data presented at the 32nd International Symposium on ALS/MND showed that it was safe and well tolerated. Furthermore, it was found that the decline in ALS Functional Rating Scale-Revised (ALSFRS-R) was comparable to the non-oral form of edaravone (Radicava). You can find out more about this trial here.

Phase 3b

The Phase 3b trial aimed to evaluate and compared the efficacy of two dosing reimens of oral edaravone (MT-1186) in people with ALS. The trial used the change in ALS Functional Rating Scale-Revised (ALSFRS-R) score from baseline. The trial aimed to determine whether taking a daily dose of oral edaravone would be more beneficial for people with MND compared to the FDA approved on/off 28-day cycle dose. Pre-planned interim analysis from the trial showed that if the trial continued to the end of 48 weeks there would be a low chance of the daily dose being more beneficial than the on/off 28-day cycle dose. This led to the trial ending early. You can read more about the trial here.

Latest News


August 2023 - The Phase 3b trial comparing two different dosing regimes has been stopped early. Pre-planned interim analysis suggested that there was a low chance that the daily dose would be more beneficial than the on/off 28-day cycle dose at the end of the trial. You can read more here.


May 2022 - The FDA announced that oral edaravone (Radicava-ORS) has been approved for use in the US. You can find out more here


Jan 2022 - Mitsubishi Tanabe Pharma America announced FDA acceptance of a New Drug Application. You can find out more here.


Dec 2021 - Mitsubishi Tanabe Pharma America announced the results of the Phase 3 trial. You can read more here


The Scientific Advisory Council (SAC) Briefing Notes

The Scientific Advisory Council for the International Alliance of ALS/MND societies consists of 9 members from USA, UK (including MND Association's Head of Research - Dr Nick Cole), Sweden, Italy, South Africa, China, Australia and Canada.

They produce briefing notes as a trusted source of information about current experimental treatments in clinical development, such as Oral Edaravone.

These notes are produced after many rounds of careful discussion between the SAC members.

You can find the briefing note for Oral Edaravone here.

Last updated: 07/08/2023