The purpose of this Phase I study is to evaluate the safety and tolerability of ALLN-346 in in normal healthy volunteers, in an ascending dose design.

ALLN-346 is an (oral) enzyme that specifically degrades urate in the intestinal tract.

This is a Phase I, 7-day, randomized, double-blind, placebo-controlled, multiple ascending dose study of orally administered ALLN-346 in normal healthy volunteers. Study will take place at a clinical pharmacology unit (CPU). Two sequential cohorts will be dosed and followed for safety through Day 28.

The study will evaluate safety and tolerability (including inflammation and immunogenicity), and pharmacodynamics of ALLN-346.

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