Inclusion Criteria:  Signed informed consent obtained prior to initiation of any study-specific procedures and treatment Familial or sporadic ALS/MND diagnosed as clinically possible, probable, or definite according to Awaji-shima Consensus Recommendations Seated slow vital capacity (SVC) ≥ 3L in males and ≥ 2.5L in females at screening Not taking riluzole or on a stable dose of riluzole for at least 4 weeks prior to the screening visit. While on study, subjects are not allowed to start taking riluzole during the study Patient has a competent caregiver who can support the patient's involvement in the study, including assisting the administration of study drug  Adequate bone marrow reserve, renal and liver function:  absolute neutrophil count (ANC) ≥1500/µL; platelet count ≥ 100,000/µL; hemoglobin ≥ 9 g/dL; creatinine clearance ≥ 60 mL/min (Cockroft & Gault formula); alanine aminotransferase ALT, SGPT) and/or aspartate aminotransferase (AST, SGOT) ≤ 2 x upper limit of normal (ULN); total bilirubin ≤ 1.5 x ULN; serum albumin ≥ 2.8 g/dL Women and men with partners of childbearing potential must use effective contraception while on study treatment and women of childbearing potential must have a negative pregnancy test at screening  Exclusion Criteria:  Inability to swallow oral medications or presence of a gastrointestinal disorder (e.g., malabsorption) deemed to jeopardize intestinal absorption of study drug Dependence on mechanical ventilation (invasive or non-invasive, including Continuous Positive Airway Pressure (CPAP) or Bi-level Positive Airway Pressure (BiPAP) for any part of day or night prior to the screening visit. Dependence on mechanical ventilation is defined as being unable to lie flat (supine) without it, unable to sleep without it, or daytime use Exposure to any other investigational agent within 3 months prior to the screening visit Active gastrointestinal disease within 30 days of the screening visit. Gastro-esophageal reflux disease (GERD) is not considered active gastrointestinal disease and is not exclusionary Known immune compromising illness or treatment  Presence of any of the following clinical conditions:  drug abuse or alcoholism; unstable cardiac, pulmonary, renal, hepatic, endocrine, or hematologic disease; active infectious disease; AIDS or AIDS-related complex; diagnosis of malignancy within 2 years of screening (adequately treated basal cell or squamous cell carcinoma of skin or non-invasive bladder cancer or carcinoma in situ of the bladder, breast or cervix are allowed; unstable psychiatric illness defined as psychosis or untreated major depression within 90 days of the screening visit; neuromuscular disease other than ALS/MND Dementia that may affect either outcome measures or patient understanding and/or compliance with study requirements and procedures Women and men of childbearing potential not using effective contraception while on study treatment Women who are breast-feeding Patients at risk of or known to carry a SOD1 mutation or VCP mutation