Besifovir dipivoxil maleate delivers long-term safety, efficacy in CHB

Treatment with besifovir dipivoxil maleate (BSV) is effective and safe for long-term use in treatment-naïve and tenofovir disoproxil fumarate (TDF)-experienced patients with chronic hepatitis B (CHB), results of a phase III trial have shown.

CHB patients continued the open-label BSV study after 48 weeks of a double-blind comparison between BSV and TDF treatments. The investigators examined the antiviral efficacy and drug safety up to 144 weeks for the BSV-BSV and TDF-BSV groups.

A total of 197 patients were included in the trial, among whom 170 entered the second-year open-label phase extensional study, 158 entered the third-year open-label phase, and 153 completed the 144-week follow-up. The primary endpoint of virological response (hepatitis B virus DNA <69 IU/mL) was achieved by 87.7 percent and 92.1 percent of patients in the BSV-BSV and TDF-BSV groups, respectively, over the 144-week period (p=0.36).

No between-group difference was noted in the rates of ALT normalization and HBeAg seroconversion. There were also no drug-resistant mutations to BSV observed. Bone mineral density and renal function were well preserved in the BSV-BSV group and were significantly improved after switching therapy in the TDF-BSV group.

“BSV treatment maintained antiviral efficacy over 144-week period without any viral resistance,” the investigators said. “BSV administration was safe, well-tolerated, and effective for treatment-naïve patients with CHB as well as those who switched from TDF to BSV treatment.”

CHB remains a public health problem across the globe despite the presence of vaccines and antivirals. [J Hepatol 2017;67:370-398; Lancet 2015;386:1546-1555]