A study to investigate the safety and efficacy of AMX0035 in patients with Amyotrophic Lateral Sclerosis

Prior treatment

• Previous treatment for ALS with cellular therapies or gene therapies
• Currently enrolled on another trial involving use of an investigational therapy
• Previous treatment with PB or taurursodiol within 30 days from Screening
• Currently or previously treated within the last 30 days or planned exposure to any prohibited medications.

Other illness

• Presence of unstable psychiatric disease, cognitive impairment, dementia or substance abuse that would impair ability of the participant to provide informed consent, according to Investigator judgment.
• Clinically significant unstable medical condition (other than ALS) that would pose a risk to the participant if he/she were to participate in the trial, according to Investigator judgment
• History of known allergy to Phenylbutyrate or bile salts.
• Current severe biliary disease which may result in the Investigator medical judgment in biliary obstruction including for example active cholecystitis, primary biliary cirrhosis, sclerosing cholangitis, gallbladder cancer, gangrene of the gallbladder, abscess of the gallbladder.
• History of Class III/IV heart failure (per New York Heart Association – NYHA).

Lab values

• Renal insufficiency as defined by estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73m2 (obtained within 12 weeks from first dose).

Other

• Presence of tracheostomy or PAV.
• Implantation of Diaphragm Pacing System
• Slow Vital Capacity less than 55%.
• Abnormal liver function
• Pregnant women (confirmed by a pregnancy test within 7 days of first dose) or women currently breastfeeding.
• Participant under severe salt restriction

• Male or female, at least 18 years of age.
• Men must not plan to father a child or to provide sperm for donation for the duration of the trial and 3 months after the last dose of study drug.
• Diagnosis of ALS (clinically definite or clinically probable), made by a physician who is experienced with management of ALS, as defined by the World Federation of Neurology revised El Escorial criteria.
• Time since onset of first symptom of ALS should be <24 months.
• If the participant is to be treated with riluzole and/or edaravone during the course of the trial, then treatment with riluzole and/or edaravone was, at the time of the baseline visit, previously started and maintained at a stable regimen for at least 14 days for riluzole and/or for a full treatment cycle for edaravone.
• Capable of providing informed consent.
• Capable and willing to follow trial procedures including visits to the trial clinic, remote visits, and status reporting requirements.
• Women of childbearing potential (WOCBP; e.g., not post-menopausal for at least one year or surgically sterile) must agree to use adequate birth control for the duration of the trial and 3 months after the last dose of study drug.
• Women must not be pregnant or planning to become pregnant for the duration of the trial and 3 months after last dose of study drug.
• Men must agree to practice contraception for the duration of the trial and for at least 3 months after last dose of study drug