Phase IIb trial of in vivo electroporation mediated dual-plasmid hepatitis B virus DNA vaccine in chronic hepatitis B patients under lamivudine therapy

Table 1 Characteristics of the modified intent-to-treat population

Characteristic	Vacc. (n = 107)	Ctr. (n = 115)	P value
Demographics
Age, median (IQR)	28.9 (23.1-37.1)	29.3 (24.0-35.4)	0.950
Male sex, n (%)	86 (78.9)	86 (74.1)	0.400
Weight (kg), median (IQR)	62.5 (56.0-70.0)	63.0 (56.0-70.0)	0.907
Genotype B, n (%)	42/107 (39.3)	39/115 (33.9)	0.409
Week 0 laboratory results
ALT (IU/L), median (IQR)	119.0 (94.0-167.5)	136.0 (102.6-195.3)	0.066
HBV DNA (log10 IU/mL), median (IQR)	8.1 (7.7-8.3)	8.1 (7.5-8.4)	0.9532
HBeAg (COI), median (IQR)	852.0 (223.5-1093.0)	926.6 (508.5-1076.0)	0.1972
HBsAg (IU/mL), median (IQR)	10261.0 (3953.0-24089.0)	8637.0 (2748.0-24436.0)	0.7542
Week 12 laboratory results1
HBV DNA (log10 IU/mL), median (IQR)	3.5 (2.6-4.5)	3.4 (2.6-4.6)	0.7542
HBeAg (COI), median (IQR)	147.4 (15.6-650.0)	45.9 (11.9-1011.0)	0.6052
HBsAg (IU/mL) median (IQR)	4072.0 (1608.0-8514.0)	3023.5 (1167.0-11194.0)	0.4602

¹The time point when the injection of study agent started;

²Analyzed with Wilcoxon Rank Sum test. mITT: Modified intent-to-treat; LAM: Lamivudine; IQR: Interquartile ranges; ALT: Alanine aminotransferase; COI: Semi-quantification by S/CO [the signal value ratio of sample (S) to the control (CO)]; Vacc.: LAM + vaccine arm; Ctr.: LAM + placebo arm.

Table 2 Cumulative number of patients in the per-protocol set with adefovir add-on treatment due to lamivudine antiviral failure at each time point of the trial n (%)

Week	Vacc. (n = 102)	Ctr. (n = 113)
24	1 (0.98)	0 (0.00)
36	2 (1.96)	1 (0.88)
40	4 (3.92)	5 (4.42)
48	7 (6.86)	8 (7.08)
52	11 (10.78)	14 (12.39)
56	17 (16.67)	18 (15.93)
60	27 (26.47)	26 (23.01)
64	34 (33.33)	32 (28.32)

Vacc.: LAM + vaccine arm; Ctr.: LAM + placebo arm; ADV: Adefovir; LAM: Lamivudine.

Table 3 Virological responses after the end of treatment with DNA vaccination or placebo injection in contrast to the baseline at week 12 in different analysis populations

Population	Response	12 wk after EOT (week 48)			28 wk after EOT (week 64)			36 wk after EOT (week 72)
		Vacc.	Ctr.	P value	Vacc.	Ctr.	P value	Vacc.	Ctr.	P value
mITT	No. of patients	107	115		107	115		107	115
	HBV DNA (log10 IU/mL), median (IQR)	3.06 (0-4.63)	3.05 (1.43-5.02)	0.742	2.18 (0-5.01)	2.78 (1.41-4.86)	0.164	1.88 (0-4.36)	2.37 (0-5.38)	0.329
	HBV DNA > 2 log10 IU/mL decrease, n (%)	11 (10.3)	4 (3.48)	0.044	13 (12.2)	6 (5.2)	0.065	10 (9.4)	7 (6.1)	0.362
	HBV DNA undetectable, n (%)	27 (25.2)	23 (20.0)	0.351	30 (28.0)	20 (17.4)	0.058	24 (22.4)	26 (22.6)	0.975
	HBeAg > 1 log10 IU/mL decrease, n (%)	22 (20.6)	22 (19.1)	0.789	ND	ND		37 (34.6)	27 (23.5)	0.068
	HBeAg seroconversion, n (%)	16 (15.0)	10 (8.7)	0.147	ND	ND		18 (16.8)	15 (13.0)	0.429
dPPS	No. of patients	98	108		75	87		68	81
	HBV DNA (log10 IU/mL), median (IQR)	2.99 (0-4.59)	3.05 (1.43-5.02)	0.593	2.16 (0-4.66)	2.78 (1.41-4.86)	0.104	1.85 (0-3.78)	2.37 (0-5.38)	0.262
	HBV DNA > 2 log10 IU/mL decrease, n (%)	11 (11.2)	4 (3.8)	0.038	13 (17.3)	6 (7.1)	0.040	10 (14.7)	7 (8.9)	0.246
	HBV DNA undetectable, n (%)	27 (27.6)	23 (21.3)	0.296	29 (38.7)	20 (23.0)	0.030	24 (35.3)	26 (32.1)	0.681
	HBeAg > 1 log10 IU/mL decrease, n (%)	20 (20.4)	21 (19.4)	0.863	ND	ND		29 (42.7)	25 (30.9)	0.136
	HBeAg seroconversion, n (%)	16 (16.3)	10 (9.3)	0.127	ND	ND		18 (26.5)	15 (18.5)	0.244
Subgroup1	No. of patients	11	19		11	19		11	19
	HBV DNA (log10 IU/mL), median (IQR)	0 (0-1.16)	1.43 (0-2.64)	0.268	0 (0-0)	1.73 (0-3.6)	0.053	0 (0-0)	0 (0-4.32)	0.172
	HBV DNA undetectable, n (%)	8 (72.7)	7 (36.8)	0.128	8 (72.7)	8 (44.1)	0.142	7 (63.6)	9 (47.4)	0.466
	HBeAg seroconversion, n (%)	5 (45.5)	2 (10.5)	0.068	ND	ND		6 (54.6)	3 (15.8)	0.042
dPPS of subgroup2	No. of patients	11	19		9	18		9	17
	HBV DNA (log10 IU/mL), median (IQR)	0 (0-1.16)	1.43 (0-2.64)	0.268	0 (0-0)	1.73 (0-3.6)	0.053	0 (0-0)	0 (0-4.32)	0.172
	HBV DNA undetectable, n (%)	8 (72.7)	7 (36.8)	0.128	8 (88.9)	8 (44.4)	0.042	7 (77.8)	9 (52.9)	0.399
	HBeAg seroconversion, n (%)	5 (45.5)	2 (10.5)	0.068	ND	ND		6 (66.7)	3 (17.7)	0.028

¹Subgroup, 30 patients with HBV DNA < 1000 copies/mL (1.79 × 10² IU/mL) at week 12;

²dPPS of subgroup, population for analysist of the 30 patients with HBV DNA < 1000 copies/mL (1.79 × 10² IU/mL) at week 12 by ruling out the ADV add-on cases at each time point instantly after ADV administration due to lamivudine (LAM) antiviral failure. Data were analyzed with Fisher’s exact test. mITT: Modified intent to treat; dPPS: Dynamic per-protocol set by ruling out the adefovir (ADV) add-on cases at each time point instantly after ADV administration due to lamivudine (LAM) antiviral failure; ND: Not detected; Vacc.: LAM + DNA vaccine arm; Ctr.: LAM + placebo arm.

Table 4 Hepatitis B virus antigen-specific T-cell responses in 45 patients from week 50 to 70 after the trial n (%)

Positive response	Vacc. (n = 22)	Ctr. (n = 23)	P value
1IFN-γ secretion	19 (86.4)	13 (56.5)	0.047
2CD3 + CD8 + IFN-γ	17 (77.3)	10 (43.5)	0.021

¹A positive T-cell response was defined as an increase in interferon-γ (IFN-γ) secretion by two times compared to the control level, tested by ELISA, that in itself was no less than 100 pg/mL upon 9 d cultivation of PBMCs stimulated by HBsAg;

²A positive T-cell response was defined as no less than 0.1 percentage frequency of CD8 cells showing positive IFN-γ intracellular staining, tested by FACS, upon stimulation by various HBV envelope antigens. Vacc.: LAM + DNA vaccine arm; Ctr.: LAM + placebo arm.