Drug development for chronic hepatitis B functional cure: Recent progress

Table 1 Current available drugs for the treatment of chronic hepatitis B

Types of drugs	Name	Antiviral mechanism	Limitations/comments
Immunomodulators	IFN-2α and PEG-IFN-2α	Inhibit HBV replication Activate antiviral immune responses	Poor tolerability; Anti-PEG antibody mediated immune clearance[4]
Nucleoside analogue	ETV	HBV DNA polymerase inhibitor	High potency and low resistance
Nucleotide analogue	TDF	HBV DNA polymerase inhibitor	Potent, but with kidney and bone toxicity concern in long-term use
Nucleotide analogue	TAF	HBV DNA polymerase inhibitor	TDF analog with improved renal and bone safety profiles
Nucleotide analogue	ADV	HBV DNA polymerase inhibitor	Less potent, nephrotoxicity
Nucleoside analogue	3TC	HBV DNA polymerase inhibitor	Less potent, high rate of resistance
Nucleoside analogue	LdT	HBV DNA polymerase inhibitor	High rate of resistance

HBV: Hepatitis B virus; ETV: Entecavir; TAF: Tenofovir alafenamide; ADV: Adefovir dipivoxil; 3TC: Lamivudine; LdT: Telbivudine; TDF: Tenofovir disoproxil fumarate; IFN-2α: Interferon alpha-2α; PEG-IFN-2α: Pegylated IFN-2α.