A Study to Evaluate ALN-XDH in Healthy Subjects and Patients With Gout

A Phase 1/2, Randomized, Double-blind, Placebo-controlled, Single Ascending and Multiple Dose Study of the Safety, Tolerability, Efficacy, Pharmacokinetics, and Pharmacodynamics of ALN-XDH in Healthy Adult Subjects and Adult Patients With Gout

The purpose of this study is to:

• Part A: Evaluate the safety and tolerability of single ascending doses of ALN-XDH in healthy adult participants
• Part B: Evaluate the safety, tolerability and efficacy of ALN-XDH as monotherapy in adult patients with gout
• Part C: Evaluate the safety, tolerability and efficacy of ALN-XDH as add-on therapy in adult patients with gout

Inclusion Criteria:

• Part A: has serum uric acid (sUA) level ≥4 mg/dL and ≤7 mg/dL
• Parts B and C: meets the American College of Rheumatology criteria for acute arthritis of primary gout
• Part B: has an sUA level ≥8 mg/dL while not receiving urate-lowering therapy (ULT) or following a 1-week washout period of prior ULT
• Part C: has been on a stable dose of allopurinol for gout for ≥6 weeks prior to screening
• Part C: has an sUA level ≥6 mg/dL

Exclusion Criteria:

• Parts A, B and C: Has received an investigational agent within the last 30 days
• Parts A, B and C: Has experienced or is being treated for acute gout flare(s) within 14 days prior to randomization