HEPATITIS B · White paper
Hepatitis B Clinical Trials
Approved therapies, the pivotal-trial endpoints they were judged on, the magnitude of benefit — and the drugs that failed their endpoints, and why.
Indication overview
About hepatitis b — and why its trials are hard
Hepatitis B (HBV) is a DNA virus that infects the liver and can cause acute or chronic disease, with chronic infection driving fibrosis, cirrhosis, and hepatocellular carcinoma. Around 296 million people were living with chronic HBV in 2019, with roughly 820,000 deaths annually. Chronicity depends heavily on age at infection, occurring in about 5-10% of infected adults but up to 90% of perinatally infected infants. The 1982 vaccine dramatically reduced transmission, and nucleos(t)ide analogues such as entecavir and tenofovir provide potent, durable viral suppression with a high barrier to resistance. Critically, current therapies suppress rather than cure: they control HBV DNA and reduce complications but rarely clear HBsAg, so most patients require long-term or lifelong treatment, a central unmet need known as the functional-cure gap. Trials are built on virologic endpoints, HBV DNA suppression, HBeAg and HBsAg seroconversion/loss, ALT normalization, and histologic improvement, with novel siRNA, antisense, and immunomodulatory agents pursuing finite-duration functional cure.
Approved therapies & pivotal evidence
What's been approved — and by how much it moved the endpoint
| Drug (brand) | Approved | Setting | Pivotal trial | Primary endpoint | Magnitude of benefit |
|---|---|---|---|---|---|
| Entecavir (Baraclude) | 2005 | First-line chronic HBV (nucleoside analogue) | ETV-022 / ETV-027 | HBV DNA suppression, histologic and ALT improvement at 48 weeks | Superior HBV DNA suppression vs lamivudine with very low resistance |
| Tenofovir disoproxil fumarate (Viread) | 2008 | First-line chronic HBV (nucleotide analogue) | Study 102 (HBeAg-) / Study 103 (HBeAg+) | HBV DNA <400 copies/mL at week 48 | HBV DNA suppression in ~76% (HBeAg-) and ~67% (HBeAg+); superior to adefovir |
| Tenofovir alafenamide (Vemlidy) | 2016 | First-line chronic HBV, improved renal/bone safety | Studies 108 and 110 | HBV DNA <29 IU/mL at week 48 | Non-inferior viral suppression to TDF with less renal and bone toxicity |
| Peginterferon alfa-2a (Pegasys) | 2005 | Finite-duration therapy in selected patients (immunomodulator) | Registrational HBeAg+/- studies | HBeAg seroconversion and HBV DNA suppression after treatment | ~32% HBeAg seroconversion; higher chance of HBsAg loss than analogues but poorly tolerated |
| Lamivudine (Epivir-HBV) | 1998 | Historic first oral nucleoside analogue for HBV | Registrational lamivudine studies | HBV DNA suppression and histologic improvement | Effective early suppression but high cumulative resistance (~70% at 5 years) |
Where trials have failed
Drugs that missed their endpoint — and what contributed
The most instructive lessons in hepatitis b development come from programmes that failed the endpoint that mattered.
| Drug / trial | Endpoint outcome | What contributed |
|---|---|---|
| ARC-520 (RNA interference) — NCT02065336 (Arrowhead) | Failed to achieve significant, sustained HBsAg reduction in humans; program halted | Insufficient durable antigen loss and a hepatotoxicity signal in non-clinical/primate work |
| Clevudine (with tenofovir combination) — NCT00823342 | Trial terminated for safety; combination did not meaningfully enhance efficacy | Clevudine-associated myopathy/long-term toxicity risk outweighed benefit |
| Bepirovirsen (antisense oligonucleotide) — B-Clear (NCT04449029) | Sustained HBsAg and HBV DNA loss in only ~9-10% at 300 mg weekly for 24 weeks; insufficient for functional cure as monotherapy | Low functional-cure rate; larger/longer trials and combination approaches recommended (unverified as approved) |
Choosing the right endpoint
Primary endpoints that matter in hepatitis b trials
- HBV DNA suppression — Core virologic endpoint (undetectable/below assay limit), reflecting viral replication control
- HBsAg loss / seroconversion — Surrogate for functional cure; rare with current therapy and the key benchmark for novel agents
- HBeAg seroconversion — Marker of immune control in HBeAg-positive disease
- ALT normalization — Indicates reduced hepatic inflammation and injury
- Histologic / fibrosis improvement — Demonstrates reduced liver damage and lower cirrhosis/HCC risk over time
How iNGENū runs hepatitis b trials
Physician-led design, built for FDA submission
Endpoint & biomarker strategy
Board-certified specialists design endpoints and patient selection aligned to current FDA guidance for this indication.
FDA-ready data
Built to ICH-GCP and 21 CFR 312.120, with direct FDA submission — data accepted by the FDA, EMA and MHRA.
Faster, lower-cost delivery
~4-week ethics via the TGA CTN scheme, up to 43.5% R&D rebate, and 80–90% below US CRO cost.
The full white paper: approved-product analyses, pivotal endpoints and trial-design strategy. Open-access · no sign-in.
Frequently asked questions
Hepatitis B clinical trials — FAQs
Can hepatitis B be cured?
What is the difference between viral suppression and functional cure?
Why is HBsAg loss such an important endpoint?
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