Table 2. Comparison of approved first-line treatments for chronic hepatitis B.
| Peg-IFN | ETV | TDF | |
|---|---|---|---|
| Indications | |||
| HBeAg+, normal ALT | Not indicated | Not indicated | Not indicated |
| HBeAg+ chronic hepatitis | Indicated | Indicated | Indicated |
| HBeAg− chronic hepatitis | Indicated | Indicated | Indicated |
| Duration of treatment | |||
| HBeAg+ chronic hepatitis | 12 months | ≥1 year until e Ag seroconversion | ≥1 year until e Ag seroconversion |
| HBeAg− chronic hepatitis | 1 year | >1 year, likely lifelong until HBsAg clearance | >1 year, likely lifelong until HBsAg clearance |
| Route | Subcutaneous | Oral | Oral |
| Side effects | Many | Negligible | Negligible |
| Drug resistance | Not applicable | 1.2% up to year 5 | 0% up to year 5 |
| Cost | Moderate as limited duration of therapy | High especially with lifelong therapy | High especially with lifelong therapy |
ETV, entecavir; HBeAg, hepatitis B e antigen; HBsAg, hepatitis B surface antigen; peg-IFN, pegylated interferon-a2α TDF, tenofovir.