Table 1.

Limitations of commercially available antiviral drugs and possible underlying causes.

Limitation of IFNs and NUCs	Possible Causes
IFNs and NUCs are unable to eradicate or substantially control cccDNA that acts as a template for HBV replication.	Interferons and nucleoside analogs are repurposed antiviral drugs developed for other viral infections. Thus, these drugs are not evidence-based drugs for CHB.
The liver-protecting capacities and potency to block progression to LC and HCC are nominal for IFNs and NUCs.	The immune modulatory capacity and the nature of immune modulation of IFNs and NUCs are not purpose-oriented.
NUCs is an infinite mode of therapy, and there is a need to continue NUC intake for years or even for life.	The half-life of NUCs is, at best, 60 h. Thus, the effect of NUCs would be of limited duration. Cessation of NUCs will favor a milieu of HBV replication.
NUCs are not patient-friendly for developing and resource-constrained countries.	The infinite usage of NUCs along with periodic check-ups is unfriendly to developing countries that harbor 80% of CHB patients.
Use of NUCs confuses patients in developing countries.	NUCs induce HBV DNA negativity after usage for a short duration. Many CHB patients consider this as a remedy from the disease and give up taking medication. However, the drug must be taken for a prolonged duration.