Antivirals are typically used as chronic treatment to suppress the hepatitis B virus, but several companies are attempting to achieve virtual cures of the virus. Assembly Biosciences, Inc., focused on core inhibitors of HBV, tried to achieve a bridge between chronic treatment and a cure with finite therapy – a limited course of treatment that would yield lasting viral suppression – but a Phase II combination study fell well short of its mark, as 39 of 41 patients relapsed after treatment was stopped.
The South San Francisco-based firm revealed on 5 November that the open-label Phase II Study 211 did not meet an intended bar of at least 15% of patients achieving sustained viral response – defined as undetectable serum levels of virus – for up to 24 weeks after 12-18 months on combination therapy