Terminated as it is considered that necessary data have been collected

The purpose of this study is to evaluate the safety, tolerability and efficacy of trametinib (SNR1611) in the treatment of amyotrophic lateral sclerosis.

Trametinib (SNR1611) is a MEK inhibitor that downregulates the MAPK/ERK pathway. In this study, the potential of MAPK/ERK pathway downregulation through trametinib (SNR1611) as a therapeutic treatment for amyotrophic lateral sclerosis (ALS) will be evaluated.

Main inclusion criteria:

• Patients diagnosed as definite, probable or probable-laboratory-supported ALS according to El Escorial Criteria.
• Patients of less than 2 years after the onset of ALS.
• Patients who meet the criteria of K-ALSFRS-R score and forced vital capacity.

Main exclusion criteria:

• Patients with primary lateral sclerosis, progressive muscular atrophy or lower motor neuron disease.
• Patients who have history of ALS treatment of edaravone or stem cell therapy within 16 weeks before screening.
• Patients who have permanently ceased the administration of riluzole due to lack of tolerability and/or efficacy.
• Patients in Class II to IV according to the New York Heart Association functional classification. Patients with myocardial infarction, unstable arrhythmia, and/or significant cardiovascular disease such as unstable angina within 12 weeks before screening.
• Patients who do not meet the criteria of laboratory tests and medical/operation history.

K-ALSFRS-R score will be measured by independent outcome assessors.