Single ascending doses of AP-101 will be administered by intravenous (IV) infusion

Inclusion Criteria:

• All participants must adhere to contraception restrictions

• Female patients of non-childbearing potential due to:

  1. Menopause: spontaneous amenorrhea for at least 12 months not induced by a medical conditions such as anorexia nervosa and not taking medications that induced the amenorrhea (e.g., oral contraceptives, hormones, gonadotropin releasing hormones, anti-estrogens, selective estrogen receptor modulators, or chemotherapy)
  2. Surgical sterilization

• Have possible, probable, probable laboratory supported or definite and definite familial laboratory-supported ALS in accordance with the El-Escorial criteria

• Have familial or sporadic ALS.

• With onset of ALS symptoms, specifically onset of muscle weakness within past 48 months

• Have slow vital capacity (SVC) of (greater than or equal to) ≥60%

• If on riluzole, must be on a stable dose

• If on edaravone, must have completed 2 cycles and are expected to remain on the same dose throughout the study

• Able to provide informed consent. If the patient is not able to provide written consent due to aggravation of disease condition, written informed consent may be provided by a legally authorized representative

• Have venous access sufficient to allow for blood sampling

• Have clinical laboratory test results within normal reference range for the population or study site, or results with acceptable deviations that are judged to be not clinically significant

Exclusion Criteria:

• Are currently enrolled in, or discontinued from, within the last 30 days, a clinical trial involving an investigational drug or device or off-label use of a drug or device, or any other type of medical research judged not to be scientifically or medically compatible with this study
• Have previously completed or withdrawn from this study
• Have a history or presence of medical illness including, but not limited to, any cognitive, cardiovascular, hepatic, hematological, renal, endocrine, or psychiatric, or any clinically significant laboratory abnormality that indicates a medical problem that would preclude study participation
• Show evidence of human immunodeficiency virus (HIV) infection and/or positive human HIV antibodies
• Show evidence of hepatitis C and/or positive hepatitis C antibody
• Show evidence of hepatitis B and/or positive hepatitis B surface antigen
• Are women who are lactating.
• Have undergone a tracheostomy unless it was removed at least 6 months prior
• Are on feeding tube, unless the insertion of a feeding tube is considered prophylactic
• Are on nasal intermittent positive pressure ventilation (NIPPV) >4 hours per day or at the discretion of the medical monitor
• Have undergone stem cell therapy