BRB-018-001 will be conducted as a multicenter, adaptive design, randomized, parallel group study to evaluate the safety, tolerability, and PK of repeat IV doses of RYI-018 in subjects with NAFLD. Subjects in each cohort shall be randomized to either RYI-018 or placebo as weekly injection for four weeks. The active doses of RYI-018 will be as follows: Cohort 1: 0.6 mg/kg, Cohort 2: 1.2 mg/kg, and Cohort 3: 2.5 mg/kg. Primary endpoints include safety and tolerability. Secondary endpoints include pharmacokinetics and immunogenicity.