1Division of Gastroenterology, Department of Medicine, New York University Langone Medical Center, New York University School of Medicine, New York, United States of America.
2San Jose Gastroenterology, San Jose, California, United States of America.
3AE & LY Medical Associates, Flushing, New York, United States of America.
4Asian Pacific Liver Center, St. Vincent Medical Center, Los Angeles, California, United States of America.
5Nexus Development, Palo Alto, California, United States of America.
6Sing Chan Endoscopy, Flushing, New York, United States of America.
BACKGROUND AND AIMS:
Chronic hepatitis B (CHB) disproportionately affects the Asian-American population in the USA. Tenofovir disoproxil fumarate (TDF) has demonstrated potent antiviral activity in clinical trials, but data in Asian-Americans from community studies are lacking.
Adult Asian-American patients with CHB from private medical and community-based practices were prospectively enrolled and treated with open-label TDF 300 mg once daily in a single-arm study for 48 weeks. After Week 48, patients had the option to transition to commercially available CHB therapy. The primary efficacy endpoint was hepatitis B virus (HBV) DNA <400 copies/mL at Week 48. Secondary endpoints were safety and tolerability, serologic and biochemical responses, liver fibrosis by FibroTest, and the development of drug-resistant mutations.
Of the 90 patients enrolled, 53 (58%) were hepatitis B e antigen (HBeAg)-positive at baseline. At Week 48, 74 patients (82% overall; 70% HBeAg-positive and 100% HBeAg-negative) had HBV DNA <400 copies/mL. Six (12%) HBeAg-positive patients achieved HBeAg loss/seroconversion. The percentage of patients with alanine aminotransferase in the normal range increased from 26% at baseline to 66% at Week 48. The percentage of patients with F0 (no or minimal) fibrosis by FibroTest increased from 48% to 51%, and those with F4 (severe) fibrosis decreased from 4% to 1%. No resistance to TDF developed. Treatment was well tolerated. Most adverse events were mild in severity and considered unrelated to study drug.
TDF is effective and well tolerated in Asian-American CHB patients in community clinic-based settings, consistent with larger registration trials. Improvement in liver fibrosis was seen in a proportion of patients. No resistance to TDF developed through 48 weeks of treatment.
Clinicaltrial.gov identifier NCT00736190.