Study 102: Multiple Ascending Dose Study of ALLN-346 (Engineered Urate Oxidase)

Inclusion Criteria: * Male or female, age 18 to 55 years * Incapable of pregnancy, not nursing, and agrees to use an effective method of contraception; males subjects must agree to abstain from sperm donation * Good general health as determined by medical history and physical examination * Normal clinical laboratory test results and ECG Exclusion Criteria: * Presence or history of any significant cardiovascular, gastrointestinal, hepatic, renal, pulmonary, hematologic, endocrine, immunologic, dermatologic, neurological, psychiatric disease or history of hyperuricemia * Any other condition (including surgery) known to interfere with the absorption, distribution, metabolism, or excretion of medicines * Positive screen results for drugs of abuse, alcohol, or cotinine or recent history of drug or alcohol abuse, or positive COVID-19 test * Clinically significant abnormal findings on physical examination, vital signs or on electrocardiogram (ECG) * Positive test result for hepatitis B surface antigen, hepatitis C virus antibody, or human immunodeficiency virus (HIV) antibody * Received treatment with or exposure to an Investigational drug or device within 30 days prior to or during Screening * Prior dosing in ALLN-346 clinical study * Per Investigator judgment, is not an ideal clinical study candidate