Amyotrophic lateral sclerosis (ALS) is a severe neurodegenerative condition, mainly characterized by progressive weakness and wasting of the limbs, the respiratory and bulbar muscles. Respiratory insufficiency leads to a fatal outcome after a mean diseases duration of only three to five years. The disease is characterized by pathological accumulations of a protein called TDP-43, which can be found large cortical and sub-cortical areas of post-mortem ALS brains.

No causal treatment for this condition is known to date, and there is a large unmet need to develop new strategies in order to halt or slow down its progression.

The aim of this study is to test the safety and tolerability of Tideglusib, a treatment that is already in clinical trials for other neuromuscular conditions, in patients with ALS. It is assumed that this drug may have a significant therapeutic benefit in this population due to his mode of action: In the ALS mouse model, Tideglusib decreases significantly the amount of accumulated TDP-43 proteins within the cells.

Inclusion Criteria:

• Possible, probable (clinically or laboratory supported) or definite ALS according to the revised version of the El Escorial criteria
• Disease duration < 18 months
• Vital capacity of more than 60% of normal (defined as slow vital capacity, best of three measurements)
• Age more than 18 years
• On a stable dose of riluzole for at least four weeks or not taking riluzole
• On a stable dose of edaravone for at least four weeks or not taking edaravone
• Capable of thoroughly understanding all information given and giving full informed consent according to GCP

Exclusion Criteria:

• Previous participation in another clinical study within the preceding 12 weeks
• Proven SOD1- or FUS - mutation
• Tracheostomy or assisted ventilation of any type during the preceding three months
• Pregnancy or breast-feeding females
• Any medical condition known to have an association with motor neuron dysfunction which might confound or obscure the diagnosis of ALS
• Presence of any concomitant life-threatening disease or impairment likely to interfere with functional assessment
• Evidence of a major psychiatric disorder or clinically evident dementia precluding evaluation of symptoms
• Alcoholism
• Cardiovascular disorder/arrhythmia
• Impaired kidney function, defined as creatinine levels of 2.5 x upper limit of normal (ULN)
• Impaired liver function, defined as aspartate aminotransferase (AST) or alanine aminotransferase (ALT) of 3 x ULN
• Liable to be not cooperative or comply with trial requirements as assessed by the investigator, or unable to be reached in the case of emergency

Double-blind