Efficacy and safety of tenofovir alafenamide in patients with chronic hepatitis B exhibiting suboptimal response to entecavir

Table 1 Baseline characteristics of the study population

Variable	ETV group (n = 30)	TAF group (n = 30)	P value
Age (yr)	46.2 ± 9.8	45.3 ± 10.2	0.69
Sex (male/female)	20/10	19/11	0.77
Body mass index (kg/m2)	24.5 ± 3.2	24.7 ± 3.4	0.82
HBeAg status (positive/negative)	12/18	12/18	> 0.99
Baseline HBV DNA (log 10 IU/mL)	3.7 ± 1.2	3.5 ± 1.1	0.48
Baseline ALT (U/L)	51.3 ± 28.6	49.7 ± 26.4	0.82
Duration of ETV treatment (months)	18.4 ± 6.2	18.7 ± 5.9	0.84

Data are presented as mean ± SD or number. ETV: Entecavir; TAF: Tenofovir alafenamide; HBV: Hepatitis B virus; ALT: Alanine aminotransferase.

Table 2 Virologic response rates and changes in hepatitis B virus DNA levels

Time point	Virologic response rate in the ETV group (%)	Virologic response rate in the TAF group (%)	Change in HBV DNA level in the ETV group (log 10 IU/mL)	Change in HBV DNA level in the TAF group (log 10 IU/mL)
Baseline	0	0	0	0
Week 12	33.3	53.3	-1.8	-2.6
Week 24	50	76.7	-2.2	-3.2
Week 36	60	86.7	-2.4	-3.6
Week 48	66.7	93.3	-2.4	-3.8

ETV: Entecavir; TAF: Tenofovir alafenamide; HBV: Hepatitis B virus.

Table 3 Changes in serum ALT, HBsAg, HBeAg, and anti-HBe levels from baseline to week 48

Variable	ETV group (n = 30)	TAF group (n = 30)	P value
ALT (U/L)	-16.7 ± 21.4	-18.3 ± 19.6	0.72
HBsAg (log 10 IU/mL)	-0.1 ± 0.3	-0.2 ± 0.4	0.31
HBeAg (S/CO)	-1.2 ± 2.4	-1.4 ± 2.6	0.69
Anti-HBe (S/CO)	0.2 ± 0.5	0.8 ± 1.1	0.03

Data are presented as mean ± SD. ETV: Entecavir; TAF: Tenofovir alafenamide; HBV: Hepatitis B virus; ALT: Alanine aminotransferase; HBsAg: Hepatitis B surface antigen; HBeAg: Hepatitis B e antigen.

Table 4 Rates of alanine aminotransferase normalization, hepatitis B e antigen loss, hepatitis B e antigen seroconversion, and hepatitis B surface antigen loss at week 48

Outcome	ETV group (n = 30)	TAF group (n = 30)	P value
ALT normalization (%)	76.7	80.0	0.72
HBeAg loss (%)	25.0	33.3	0.51
HBeAg seroconversion (%)	8.3	33.3	0.04
HBsAg loss (%)	0.0	0.0	> 0.99

ETV: Entecavir; TAF: Tenofovir alafenamide; HBV: Hepatitis B virus; ALT: Alanine aminotransferase; HBsAg: Hepatitis B surface antigen; HBeAg: Hepatitis B e antigen.

Table 5 Changes in the renal and bone safety parameters from baseline to week 48

Variable	ETV group (n = 30)	TAF group (n = 30)	P value
eGFR (mL/min/1.73 m2)	-1.3 ± 3.2	-1.5 ± 2.9	0.76
Serum creatinine (μmol/L)	1.7 ± 5.6	2.1 ± 4.8	0.67
UPCR (mg/mmol)	-0.2 ± 0.6	-0.1 ± 0.5	0.58
BMD at lumbar spine (%)	-2.1 ± 1.4	-0.8 ± 1.2	0.004
BMD at hip (%)	-1.8 ± 1.3	-0.6 ± 1.1	0.007
Serum calcium (mmol/L)	-0.01 ± 0.05	-0.02 ± 0.04	0.42
Serum phosphate (mmol/L)	-0.03 ± 0.12	-0.04 ± 0.11	0.69
Serum alkaline phosphatase (U/L)	-3.7 ± 12.4	-4.3 ± 11.6	0.79
Serum parathyroid hormone (pg/mL)	-2.4 ± 8.7	-3.1 ± 9.2	0.68

Data are presented as mean ± standard deviation. ETV: Entecavir; TAF: Tenofovir alafenamide; BMD: Bone mineral density; eGFR: Estimated glomerular filtration rate; UPCR: Urine protein-to-creatinine ratio.