This is a single-arm phase II study to evaluate the efficacy and safety of Eltrombopag to treat thrombocytopenia associated with chronic hepatitis B virus infection.~This study includes two stages. In Stage 1 (Week 1 to Week 6), the short-term efficacy, safety and tolerability of Eltrombopag is evaluated. At the end of Stage 1, the subjects who can benefit from Eltrombopag treatment (platelet count ≥30×109/L at least once and a 2-fold increase from baseline platelet count without rescue therapy, with no bleeding) can enter a 16-week prolonged stage (Stage 2) to evaluate longer-term efficacy and safety.~The starting dose of Eltrombopag is 25 mg once daily, and the dose may be increased by 25 mg once daily according to protocol if the desired platelet response (>50×109/L) is not achieved. The daily dose should not exceed 75 mg.~In Stage 1, weekly visits are required during the first 6 weeks of the study. In Stage 2, platelet counts will be obtained weekly during dose adjustment and every 4 weeks following establishment of a stable dose of Eltrombopag (stable dose is defined as the dose which remains unchanged for at least 2 weeks).
Primary Objective: To evaluate the efficacy of 6-week Eltrombopag to treat thrombocytopenia associated with chronic hepatitis B virus infection. Secondary Objective: To evaluate the efficacy and safety of 6-week and 22-week Eltrombopag to treat thrombocytopenia associated with chronic hepatitis B virus infection.