A Two-Part Phase 1 Study to Investigate A) Safety and Tolerability of Supratherapeutic dose of Zanubrutinib (BGB-3111) and B) Effect of Zanubrutinib on Cardiac Repolarization in Healthy Subjects

This is a Two-Part Phase 1 Study.

Part A: This is a randomized, placebo-controlled, double blind, single dose study to evaluate the safety and tolerability of a single oral supratherapeutic dose of zanubrutinib in eight (8) subjects.

Part B: This is a randomized, placebo and positive-controlled, double-blind, 4-way crossover study being conducted in about 28 subjects to investigate the effect of a single therapeutic dose of zanubrutinib, a supratherapeutic dose of zanubrutinib and placebo on cardiac repolarization. Open-label Moxifloxacin (400 mg), a fluoroquinolone broad spectrum antibiotic will be used as a positive control.

Inclusion Criteria: All subjects

1. Body mass index (BMI) 18 - 33 kg/m2, inclusive.
2. In good general health as assessed by the Investigator.
3. Females of non-child bearing potential.
4. Males without a vasectomy will agree to use required barrier contraception, and will agree to not donate sperm from the time of the first dose of BGB-3111 until ≥ 90 days after the last dose of BGB-3111.
5. Able to comprehend and willing to sign consent.

Exclusion Criteria: All subjects

1. Subjects with a clinically relevant history or presence of any clinically significant disease.
2. Personal or known family history of congenital or acquired long QT syndrome or cardiovascular disease.
3. Women of child-bearing potential.
4. History of alcoholism or drug/chemical abuse within 6 months.

Part A: zanubrutinib and placebo will be double-blind Part B: zanubrutinib and placebo will be double-blind; Moxifloxacin will be open-label