This is a Phase 1b, multicenter, randomized, placebo-controlled, double-blind study of 28 days, followed by an 18-month open-label extension, designed to evaluate the safety, pharmacokinetics (PK), and pharmacodynamics (PD) of DNL343 in participants with amyotrophic lateral sclerosis (ALS)

This clinical trial information was submitted voluntarily under the applicable law and, therefore, certain submission deadlines may not apply. (That is, clinical trial information for this applicable clinical trial was submitted under section 402(j)(4)(A) of the Public Health Service Act and 42 CFR 11.60 and is not subject to the deadlines established by sections 402(j)(2) and (3) of the Public Health Service Act or 42 CFR 11.24 and 11.44.).

Key Inclusion Criteria:

• Diagnosis of sporadic or familial ALS
• ≤ 4 years since ALS symptom onset
• Stable doses of approved ALS treatments (riluzole and/or edaravone) for at least 2 months prior to screening
• Participants must be able to swallow the study intervention
• Vital capacity >50% predicted at screening
• Women must have been surgically sterilized, be postmenopausal, or for participants of childbearing potential, must not be pregnant, and both the participant and the male partner must use highly effective contraception
• Men, and sex partner if a woman of childbearing potential, must use highly effective contraception

Key Exclusion Criteria:

• Any history of unstable or poorly controlled psychiatric, endocrine, pulmonary, cardiovascular, gastrointestinal, hepatic, pancreatic, renal, metabolic, hematologic, immunologic, or allergic disease, or other major disorders
• Positive serum pregnancy test or currently lactating or breastfeeding
• History of malignancy within 5 years
• History of clinically significant neurologic disorders other than ALS