Precision stratification for hepatitis B functional cure: Biomarkers, machine learning and the combination-therapy era

Table 1 Selected therapeutic studies and their distinct endpoints

Study and design	Population and treatment background	Endpoint and assessment time	Results and denominator	Evidence maturity and interpretation
Imdusiran (AB-729-001)[8]. Phase 1a/b; randomized healthy part; open-label CHB parts	83 dosed: 18 healthy (12 active/6 placebo) and 65 CHB (22 single-dose/43 repeat-dose). Non-cirrhotic CHB; HBsAg ≥ 250 IU/mL; NA continued where prescribed	Primary: Safety. Healthy follow-up to day 29; CHB safety follow-up to 48 weeks, or 36 months in eligible NA discontinuers. Repeat dosing up to 48 weeks	No functional-cure n/N reported in the verified abstract. All 83 comprised the safety population	Early safety/antiviral study; total n includes healthy participants. Do not treat absence of a reported cure rate as zero efficacy
ARC-520/JNJ-3989 follow-up[9]. Prospective single-centre follow-up of earlier trials	53 siRNA + NA recipients (15 ARC-520/38 JNJ-3989) and 5 prior placebo recipients; 83% previously on NA; 34% HBeAg-positive	HBsAg seroclearance or HBsAg < 100 IU/mL at last follow-up (mean 52.5 months). Exact seroclearance threshold: NR; no off-all-treatment DNA composite verified	Seroclearance 1/53 (1.9%); HBsAg < 100 IU/mL 17/53 (32.1%); both 0/5 in placebo recipients	Long-term antigen durability with a small control group; not a demonstrated functional-cure comparison after withdrawal of all therapy
Xalnesiran ± immunomodulator (PIRANGA)[10]. Phase 2 randomized open-label adaptive platform	159 NA-suppressed CHB participants: Xalnesiran 100 mg (30), 200 mg (30), 200 mg + ruzotolimod (34), 200 mg + PegIFN (30), NA alone (35). NA stopping conditional	Primary: HBsAg < 0.05 IU/mL at 24 weeks after 48-week investigational treatment (week 72). HBV DNA not part of this primary endpoint	2/30 (7%), 1/30 (3%), 4/34 (12%), 7/30 (23%), and 0/35, respectively. Loss observed only with screening HBsAg < 1000 IU/mL	HBsAg loss is distinct from cure off all therapy. Small arms; exploratory baseline-HBsAg association does not establish a treatment-selection rule
JNJ-3989 ± bersacapavir (REEF-1)[11]. Phase 2b double-blind randomized trial	470 randomized across six NA-containing arms; treated/untreated and HBeAg-positive/negative strata. Reported efficacy uses modified ITT denominators	Primary: NA-stopping eligibility at week 48: HBsAg < 10 IU/mL, HBV DNA < LLOQ (20 IU/mL), HBeAg-negative and ALT < 3 × ULN	JNJ-3989 200 mg + NA: 18/94 (19%; 90%CI 13-27%); triple regimen: 8/94 (9%; 4%-15%); NA control: 1/45 (2%; 0%-10%)	Eligibility to stop NA is not functional cure. The 19% result did not involve bersacapavir; triple therapy contained JNJ-3989 100 mg
Elebsiran ± PegIFN[12]. Open-label phase 2; six cohorts	84 non-cirrhotic, NA-treated adults; entry HBsAg > 50 IU/mL and HBV DNA < 90 IU/mL. Cohort sizes 15/15/18/18/13/5; 12-48-week regimens	Primary: Safety. Secondary: HBsAg loss at any time and sustained through 24 weeks after investigational treatment. Exact HBsAg-loss threshold: NR; background NA continued	Any loss: 0/15, 1/15, 1/18, 5/18, 4/13, 0/5. Sustained loss: 0/15, 1/15, 0/18, 3/18, 2/13, 0/5 (6/84 overall)	Exploratory cohorts with unequal regimens; pooled 6/84 is not an estimate for one regimen and does not establish cure after stopping NA
Vebicorvir[14]. Randomized phase 2 placebo-controlled trial	73 non-cirrhotic NA-suppressed participants: 47 HBeAg-positive and 26 HBeAg-negative. Vebicorvir 300 mg daily or placebo added for 24 weeks	Primary: Change in HBsAg or HBeAg from baseline to week 24; continuous antigen endpoint, not an HBsAg/HBV DNA clearance composite	No between-group difference in antigen change; improved suppression of replication markers. Functional-cure n/N not reported in the verified abstract	Demonstrates antiviral activity without a demonstrated antigen-clearance advantage in this population; no inference about comparative cure efficacy
Elebsiran + BRII-179 ± interferon[15]. Phase 2a open-label randomized parallel-group study	90 CHB participants: Elebsiran alone (10), plus vaccine without interferon (41), or plus vaccine with interferon (39). Nine 4-weekly elebsiran doses	Virologic and immunologic follow-up to week 72. Sustained HBsAg loss and anti-HBs persistence evaluated; exact HBsAg-loss threshold: NR	No sustained HBsAg loss (0/90). Anti-HBs ≥ 100 IU/L persisted in approximately 40% for ≥ 32 weeks after combination treatment	Immunogenicity is not functional cure. The absence of sustained clearance in this regimen does not exclude a benefit from other vaccine-containing sequences
Bepirovirsen (B-Clear)[16]. Phase 2b randomized investigator-unblinded trial	457 ITT across four schedules: 227 on NA and 230 not on NA. For 300 mg weekly × 24 weeks: 68 on NA and 70 not on NA; background NA maintained	Primary: HBsAg < 0.05 IU/mL and HBV DNA < 20 IU/mL at every visit for 24 weeks after planned bepirovirsen end, without new antiviral rescue; week 48 for the 24-week regimen	300 mg × 24 weeks: 6/68 (9%) on NA and 7/70 (10%) not on NA	Original primary endpoint; separate from modified analyses allowing isolated blips. On-NA responses do not establish cure after stopping all therapy
Bepirovirsen (B-Well 1/2)[17]. Two replicate double-blind randomized phase 3 trials	1834 selected non-cirrhotic adults in the full analysis population on stable NA; entry HBsAg > 100 to 3000 IU/mL. Bepirovirsen 300 mg weekly or placebo for 24 weeks; eligible NA withdrawal at week 48	Primary: Functional cure at week 72, ≥ 24 weeks after all treatment stopped: HBsAg not detected (< 0.05 IU/mL) and HBV DNA < LLOQ (< 20 IU/mL or target not detected)	B-Well 1: 127/650 (20%) vs 0/328; B-Well 2: 106/570 (19%) vs 0/286	Replicated efficacy within an enriched population. HBsAg-based enrollment was not a randomized selection strategy; durability beyond current follow-up remains to be established
Bepirovirsen then PegIFN (B-Together)[19]. Phase 2b randomized open-label trial	108 ITT on stable NA throughout: 24-week (55) or 12-week (53) bepirovirsen, followed by up to 24-week PegIFN	Primary: HBsAg < 0.05 IU/mL and HBV DNA < 20 IU/mL at every visit for 24 weeks after planned PegIFN end, without new antiviral rescue; background NA continued	5/55 (9%) and 8/53 (15%), respectively; all responders had baseline HBsAg ≤ 3000 IU/mL	Proof of concept; no bepirovirsen-alone concurrent control. Cross-trial relapse comparisons do not prove the benefit of adding PegIFN
Selgantolimod[20]. Randomized phase 2 placebo-controlled trial	48 NA-suppressed participants (24 HBeAg-positive/24 negative): 39 active and 9 placebo. Weekly study drug for 24 weeks; NA continued through week 48	Primary: ≥ 1 log10 IU/mL HBsAg decline at week 24. Additional HBsAg loss through week 48; exact loss threshold: NR. No off-all-treatment composite	Primary endpoint 1/39 active; HBsAg loss 2/39 (5%) active vs 0/9 placebo through week 48	Small exploratory immunomodulator study; HBsAg loss on NA does not establish finite-treatment functional cure
NA withdrawal (STOP-NUC)[21]. Multicentre randomized stop-vs-continue trial	166 randomized; 158 analyzed, 79 per arm. HBeAg-negative; continuous long-term NA with HBV DNA < 172 IU/mL for ≥ 4 years	Primary: Sustained HBsAg loss to week 96. HBsAg assay LOD 0.05 IU/mL; HBV DNA assay LOD 10 IU/mL. Primary endpoint differs from the B-Well composite	8/79 (10.1%; 95%CI 4.8-19.5%) vs 0/79; P = 0.006. Baseline HBsAg < 1000 IU/mL subgroup: 7/25 (28%)	Selected withdrawal trial; 11/79 (13.9%) retreated. No cessation-related serious adverse events observed; small numbers do not exclude uncommon serious harm
Elebsiran + PegIFN (ENSURE)[13]. Partially randomized open-label phase 2 trial	55 randomized to PegIFN alone or plus elebsiran 200/100 mg; 31 previously vaccinated participants in a separate nonrandomized cohort. Non-cirrhotic, NA-suppressed; randomized entry HBsAg > 100 IU/mL to 3000 IU/mL	HBsAg < 0.05 IU/mL at end of 48-week treatment and 24 weeks later (week 72); HBV DNA assay LLOQ 10 IU/mL. NA continued until week 72; withdrawal assessed afterward	Week 72: 4/19 (21.1%) with 200 mg, 6/18 (33.3%) with 100 mg, 1/18 (5.6%) control. Prior-vaccine cohort: 8/19 anti-HBs responders vs 1/12 nonresponders	Randomized regimen comparison, but small samples and HBsAg enrichment. Prior-vaccine response is an exploratory association; endpoint does not establish cure off NA
OCTOPUS-1[22]. Open-label phase 2; randomized nivolumab schedules	37 virally suppressed adults; JNJ-3989 + NA with one (n = 18) or three (n = 19) nivolumab infusions. Background NA continued through week 72	Primary: HBsAg < 0.05 IU/mL at 24 weeks after the 24-week intervention (week 48); follow-up to week 72. HBV DNA LLOQ 20 IU/mL was a separate virological measure	Primary HBsAg loss: 0/18 and 0/19. One participant in the three-infusion arm achieved loss at 48-week follow-up	No internal arm without nivolumab; incremental benefit was assessed against an external REEF-1 cohort. No off-NA cure estimate. No serious or grade 3/4 adverse events; two transient asymptomatic hyperthyroidism cases
REEF-IT[23]. Open-label phase 2; regimen amended during study	54 untreated HBeAg-positive adults; JNJ-3989 + NA ± bersacapavir for 36-52 weeks, followed by 12-week PegIFN add-on. Most continued NA during follow-up; only one met NA-completion criteria	Primary: HBsAg < 0.05 IU/mL at 24 weeks after stopping all study treatment, without NA restart. Follow-up continued for 48 weeks. Assay threshold verified in NCT04439539	0/51 in the registered primary per-protocol set (54 enrolled). HBsAg loss at least once: 11/54 (20.4%); six maintained loss through follow-up week 48	On-treatment or transient antigen loss did not establish the off-all-treatment endpoint. Registry primary denominator is distinguished from the publication’s enrolled population. No deaths or serious adverse events; two stopped PegIFN
ALG-020572[24]. Double-blind, placebo-controlled phase 1	32 healthy participants (24 active/8 placebo); eight non-cirrhotic, HBeAg-negative, NA-suppressed CHB participants (6 active/2 placebo). CHB participants continued NA	Safety, pharmacokinetics and antiviral activity; planned up to seven 210-mg doses in CHB, with 12-week follow-up after the last dose. Trial stopped early for liver injury	ALT > 10 × ULN attributed to drug-induced liver injury in 4/6 active-treated CHB participants after 2-7 doses; one hospitalized. No functional-cure estimate	Three biopsies suggested drug-induced liver injury. All recovered without sequelae; development was terminated. Compound-specific serious toxicity must not be recast as a beneficial immune flare or generalized to all ASOs
Biomarker-guided NA withdrawal[25]. Multicentre randomized trial (2:1)	90 Asian patients in the modified ITT analysis: 60 stopped and 30 continued NA. HBsAg < 200 IU/mL, suppressed HBV DNA ≥ 12 months, and undetectable HBV RNA or HBcrAg; cirrhosis excluded	Published analysis: Cumulative HBsAg loss through 144 weeks. Qualitative HBsAg negativity; numerical loss threshold NR. Registry NCT04519359 lists a 72-week primary endpoint	Cumulative HBsAg loss 25.9% vs 4.2% (P = 0.013); raw event n/N NR. In the stop arm, 16/60 restarted NA; no serious adverse events were reported	Cumulative estimates are not raw proportions. Supports a selected withdrawal strategy, not isolated validation of RNA/HBcrAg added value or a broadly applicable safe-stopping rule

Evidence maturity is a narrative appraisal, not a formal certainty grade. Background NA continuation, eligibility and differing assessment intervals prevent direct cross-trial comparisons. HBsAg loss, antigen decline and NA-stopping eligibility are not interchangeable with functional cure after withdrawal of all treatment. NA: Nucleos(t)ide analogue; CHB: Chronic hepatitis B; HBeAg: Hepatitis B e antigen; HBsAg: Hepatitis B surface antigen; siRNA: Small interfering RNA; ASO: Antisense oligonucleotide; CAM: Capsid assembly modulator; PegIFN: Pegylated interferon; ALT: Alanine aminotransferase; ULN: Upper limit of normal; ITT: Intention to treat; LOD: Limit of detection; LLOQ: Lower limit of quantification; NR: Not retrievable in the sources checked for this revision, not evidence that the original report omitted the information.