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Hepatitis BSeptember 2023Summary reviewed June 2026

What the REEF-1 Trial Found — JNJ-3989 for Chronic Hepatitis B

Researchers tested JNJ-3989, a medication that lowers hepatitis B virus levels, in combination with standard drugs. About 1 in 5 patients taking the higher doses reached targets that could allow them to stop daily pills.

What the trial was testing

The REEF-1 enrolled 471 patients with hepatitis b. The study was sponsored by Janssen Sciences Ireland UC and tracked outcomes across the full group of patients who matched the trial's eligibility profile.

It was mid-stage testing (phase 2/3). Trials at this stage are designed to produce evidence regulators and physicians can act on — not just observations to follow up later.

What the results showed

19% of patients on the highest dose met targets for potentially stopping daily hepatitis B drugs.

The lancet. Gastroenterology & hepatology · 2023 · NCT03982186

These findings — that met targets for potentially stopping daily hepatitis B drugs at 48 weeks — were published in the The lancet. Gastroenterology & hepatology and represent the headline result of the study.

Researchers tracked outcomes across 471 patients enrolled in the trial. The result was consistent enough across the group that the team felt confident reporting it.

What this means for patients

For patients with hepatitis b, this result changes the calculus on what to ask their care team about. Whether it changes day-to-day care depends on factors like disease subtype, prior treatments, and where the patient is in their care journey.

What you can do now

This was mid-stage testing and JNJ-3989 is not yet FDA-approved. The treatment lowered virus levels meaningfully in many patients, which could help future therapies work better. If you have chronic hepatitis B, talk to your doctor about ongoing trials or other approved options.

Eligibility for the treatments mentioned above depends on specific test results and clinical history. Bring this summary, the trial name, and your most recent labs or pathology report to your next visit.

Open hepatitis b trials