This is a Phase 1, randomized, double-blind, placebo-controlled single ascending dose (SAD) study to evaluate the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of DNL919.

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:

• Female participants of non-childbearing potential (surgically sterilized or post menopausal) or male participants, aged 18 to 55 years, inclusive
• BMI 18.5 to <30 kg/m²
• When engaging in sex with a woman of child bearing potential, both the male participant and his female partner must use highly effective contraception

Key Exclusion Criteria:

• History of clinically significant neurologic, psychiatric, endocrine, pulmonary, cardiovascular, gastrointestinal, hepatic, pancreatic, renal, metabolic, hematologic, immunologic, or allergic disease, or other major disorders
• History of malignancy
• History of clinically significant stroke
• History of cognitive impairment
• Positive serum pregnancy test at screening, positive urine pregnancy test at baseline visit, or currently lactating or breastfeeding