Patients with the chronic neurodegenerative disease amyotrophic lateral sclerosis (ALS) have a new treatment option in the US after the FDA approved Mitsubishi Tanabe Pharma’s Radicava (edaravone).
The landmark approval – which comes around a month earlier than expected – means that ALS patients now have the first alternative drug treatment to Sanofi’s Rilutek (riluzole), which was cleared for marketing in 1995 and became available generically a few years ago.
Unusually the FDA pressed MT Pharma to file for approval of edaravone in the US after learning of its approval in Japan, where it has been sold as Radicut since 2015. The US regulator cleared the drug on the back of a six-month Japanese trial involving 137 ALS patients which showed that the drug reduced the rate of decline in daily functioning compared to placebo.
ALS is a form of motor neuron disease (MND) which leads to muscle-weakness, muscle-wasting and shortened lifespan, and affects around 5,000 people in the US according to the National Institutes of Health (NIH). Almost 80% of ALS patients die within 5 years and 90% die within 10 years.
Riluzole is the only drug available to treat the disease and is known to have only modest efficacy extending survival only by a couple of months, but efforts to develop new therapies have mostly ended in failure and there remains a chronic lack of candidates in the pipeline.
While Riluzole works by blocking nerve cell death, edaravone is described as a free radical scavenger that targets oxidative stress, a process thought to play a role in ALS. It is given intravenously over a two-week period, followed by a two-week drug holiday. Subsequent treatment cycles consist of dosing on 10 of 14 days followed by 14 days drug-free.
MT Pharma America says it intends to launch Radicava in the US by August, when the country will become the third market for the drug as an ALS treatment after Japan and South Korea.
The FDA approval was hailed by the ALS Therapy Development Institute, with CEO Steve Perrin saying that it “gives people with ALS and their doctors a new treatment option to explore together”.
“ALS is a complex disorder and it will require multiple different approaches to bring relief to all those diagnosed with ALS,” he added. “With several additional potential treatments in clinical trials today, this is a uniquely hopeful time for the ALS community.”
In March, French biotech AB Science said a pivotal trial of its lead drug masitinib for ALS hit its objectives of reducing declines in functioning when added to Riluzole therapy. The tyrosine kinase inhibitor has a novel mechanism of action, reducing inflammation and the release of cytotoxic substances thought to contribute to the neurodegenerative process in ALS.
Dutch biotech Treeway is also working on ALS and has completed initial clinical testing of an oral formulation of edaravone and it says it could overcome some of the limitations of the IV formulation, including “suboptimal exposure levels associated with the drug holidays”.