- Subjects with positive Hep B serology. Subjects with a negative HBsAg and a positive HBcAb require an undetectable/negative hepatitis B DNA test (e.g., polymerase chain reaction [PCR] test) to be enrolled, and will require prophylactic antiviral treatment (e.g., F) initiated prior to the first dose of study drug, an continued until approximately 6 to 12 months after completion of study drug(s).