['amyotrophic lateral sclerosis']
['tirasemtiv', 'placebo tablets']

        Inclusion Criteria:

          -  A diagnosis of familial or sporadic ALS (defined as meeting the possible,
             laboratory-supported probable, probable, or definite criteria for a diagnosis of ALS
             according to the World Federation of Neurology El Escorial criteria) ≤ 24 months prior
             to screening

          -  Upright SVC ≥ 70 % of predicted for age, height and sex

          -  Able to swallow tablets without crushing, and in the opinion of the Investigator, is
             expected to continue to be able to do so during the trial

          -  A caregiver if one is needed

          -  Clinical laboratory findings within the normal range or, if outside the normal range,
             deemed not clinically significant by the Investigator

          -  Male patients must agree for the duration of the study and 10 weeks after the end of
             the study to use a condom during sexual intercourse with female partners who are of
             childbearing potential (i.e., following menarche until post-menopausal if not
             anatomically and physiologically incapable of becoming pregnant) and to have female
             partners use an additional effective means of contraception (e.g., diaphragm plus
             spermicide, or oral contraceptives) or the male patient must agree to abstain from
             sexual intercourse during and for 10 weeks after the end of the study, unless the male
             patient has had a vasectomy and confirmed sperm count is zero

          -  Female patients must be post-menopausal (≥ 1 year) or sterilized, or, if of
             childbearing potential, not be breastfeeding, have a negative pregnancy test, have no
             intention to become pregnant during the course of the study, and use effective
             contraceptive drugs or devices while requiring male partner to use a condom for the
             duration of the study and for 10 weeks after the end of the study

          -  Patients must be either on a stable dose of riluzole 50 mg twice daily for at least 30
             days prior to screening or have not taken riluzole for at least 30 days prior to
             screening and are willing not to begin riluzole use until they complete study drug
             dosing

        Exclusion Criteria:

          -  At the time of screening, any use of non-invasive positive pressure ventilation
             (NIPPV, e.g. continuous positive airway pressure [CPAP] or bi-level positive airway
             pressure [BiPAP]) for any portion of the day, or mechanical ventilation via
             tracheostomy, or on any form of oxygen supplementation

          -  Patients with a diaphragm pacing system (DPS) at study entry or who anticipate DPS
             placement during the course of the study

          -  BMI of 20.0 kg/m2 or lower

          -  Unwilling or unable to discontinue tizanidine and theophylline-containing medications
             during study participation

          -  Serum chloride outside the normal reference range

          -  Neurological impairment due to a condition other than ALS, including history of
             transient ischemic attack within the past year

          -  Presence at screening of any medically significant cardiac, pulmonary, GI,
             musculoskeletal, or psychiatric illness that might interfere with the patient's
             ability to comply with study procedures or that might confound the interpretation of
             clinical safety or efficacy data, including, but not limited to:

               1. Poorly controlled hypertension

               2. NYHA Class II or greater congestive heart failure

               3. Chronic obstructive pulmonary disease or asthma requiring daily use
                  bronchodilator medications

               4. GI disorder that might impair absorption of study drug

               5. History of significant liver disease defined by bilirubin > 2 times the upper
                  limit of normal (ULN) or ALT or AST > 3 times the ULN on repeat testing

               6. Poorly controlled diabetes mellitus

               7. History of vertigo within three months of study entry

               8. History of syncope without an explainable or treated cause

               9. History of untreated intracranial aneurysm or poorly controlled seizure disorder

              10. Amputation of a limb

              11. Cognitive impairment, related to ALS or otherwise, sufficient to impair the
                  patient's ability to give informed consent and to understand and/or comply with
                  study procedures

              12. Cancer with metastatic potential (other than basal cell carcinoma, carcinoma in
                  situ of the cervix, or squamous cell carcinoma of the skin excised with clean
                  margins) diagnosed and treated within the last two years

              13. Any other condition, impairment or social circumstance that, in the opinion of
                  the Investigator, would render the patient not suitable to participate in the
                  study

              14. Patient judged to be actively suicidal or a suicide risk by the Investigator

          -  Has taken any investigational study drug within 30 days or five half-lives of the
             prior agent, whichever is greater, prior to dosing

          -  Prior participation in any form of stem cell therapy for the treatment of ALS

          -  Previously received tirasemtiv in any previous clinical trial
      