After the washout period, the patients determined to be eligible will be randomized to receive either 25 mg BID or 100 mg BID of oral PG-760564, or placebo for 12 weeks. There will be 6 treatment visits (Weeks 1, 2, 4, 6, 8, and 12) and a follow-up visit 4 weeks after the last treatment visit (Week 16). Patients will not initiate new therapies until after the 4-week follow-up is completed. Liver function tests will be evaluated at every visit.