SAD and MAD Study of AKB-9090 in Healthy Adult Participants

Key Inclusion Criteria: * Healthy adult participants with no clinically significant findings, as judged by the investigator, based on physical examination, 12-lead ECG, alcohol breath test, and clinical laboratory tests (including serum chemistry, hematology, coagulation, urine drug screen, and urinalysis). * Body mass index (BMI) greater than 18.5 and less than 32.0 kg/m\^2 at screening. * In the Investigator's opinion, willing and able to provide written informed consent and comply with the all protocol requirements, including required confinement, outpatient visits, and protocol-specified restrictions (including refraining from major lifestyle changes) from signature of the informed consent form (ICF) through the last study visit. Key Exclusion Criteria: * Clinically significant metabolic, hepatic, renal, hematologic, pulmonary, cardiovascular, gastrointestinal, musculoskeletal, dermatologic, urogenital, ophthalmologic, ear/nose/throat, psychiatric, or neurologic disorder. * History of active or recurrent malignancy within 2 years before screening or during the screening period, or currently receiving treatment or suppressive therapy for cancer, except for: 1. Treated basal cell carcinoma of the skin 2. Curatively resected squamous cell carcinoma of the skin 3. Treated colonic or cervical carcinoma in situ * Abnormal ECG findings at screening, including: 1. Severe bradycardia (heart rate \<40 beats per minute) on any measurement 2. Mean QT Interval Using Fridericia's Formula (QTcF) \>450 msec for males or \>470 msec for females * Elevated laboratory values (\>1.25 × upper limit of normal \[ULN\]) for alanine aminotransferase (ALT), aspartate aminotransferase (AST), or creatinine at the screening visit or at check-in. * Evidence of acute or chronic hepatitis B (positive hepatitis B surface antigen) or hepatitis C infection (positive hepatitis C antibody and positive hepatitis C ribonucleic acid \[RNA\] test). * Use of nicotine-containing products (including cigarettes, cigars, tobacco, gum, patches, vaping, and e-cigarettes), caffeine-containing foods or beverages, and alcohol-containing foods or beverages during study.