This study will provide extended access to patients and assess longer-term outcomes on patients who have completed the TUDCA-ALS study.

The TUDCA-ALS Open label extension study is designed to investigate long term safety, tolerability and efficacy of tauroursodeoxycholic acid in patients with ALS who completed the TUDCA-ALS study

Inclusion Criteria:

• Completion of the visit M18 (Month 18) of the TUDCA-ALS clinical trial.
• Signed informed consent for participation in the TUDCA-ALS Extension sub-study

Exclusion Criteria:

• Treatment with edaravone or other unaccepted concomitant therapy
• Consideration by the investigator, for any reason, that the subject is an unsuitable candidate to receive TUDCA or that the subject is unable or unlikely to comply with the dosing schedule or study evaluations
• The patient of reproductive potential is sexually active and is not willing to use highly effective contraception during the study and up to 90 days after the day of last dose
• The patient is pregnant or breast feeding