Dose cohorts may be dosed with one of up to 4 possible total weekly doses (0.3 mg, 1 mg, 2 mg, 4 mg). Dose escalation or repetition will be governed by pre-specified safety and activity rules. Subjects will be confined on days 1-3 and/or days 8-10. Follow-up visits are required periodically through day 43. Subjects with sustained reductions in HbsAg will be requested to return for additional follow-up follow-up visits at 3 and 6 months post last dose. Study procedures involve blood draws for pharmacokinetic, pharmacodynamic, virologic, and safety assessments