Cell experiment:

BMS 200475 is prepared in phosphate-buffered saline (PBS) and diluted with appropriate medium containing 2% fetal bovine serum. HepG2 2.2.15 cells are plated at a density of 5×105 cells per well on 12-well Biocoat collagen-coated plates and are maintained in a confluent state for 2 to 3 days before being overlaid with 1 mL of medium spiked with BMS 200475. Quantification of HBV was performed on day 10[1].

Entecavir hydrate is a reverse transcriptase inhibitor.
Reverse transcriptase (RT) is used to generate complementary DNA (cDNA) from an RNA template, which is mainly associated with retroviruses, such as HBV.
Entecavir hydrate is an oral antiviral drug used in the treatment of hepatitis B virus (HBV) infection. In 17 patients with hepatitis B virus (HBV) genotype C, treatment with peginterferon
(PEG-IFN) a-2b combination with entecavir hydrate (ETV) for 48 weeks. Among 11 patients exhibited pretherapy HBeAg, 8 showed HBeAg seroconversion. Serum HBV DNA levels reduced by 5.2 and 3.3 log copies/ml by the end of the therapy and follow-up periods, respectively. Intrahepatic cccDNA reduced to 1.4 log copies/mg.  
References:
[1]. Hagiwara S, Kudo M, Osaki Y, et al. Impact of peginterferon alpha-2b and entecavir hydrate combination therapy on persistent viral suppression in patients with chronic hepatitis B. J Med Virol, 2013, 85(6): 987-995.