Background In the hepatitis B e antigen positive (HBeAg+) chronic infection disease phase, approved treatments have limited effects on hepatitis B surface antigen (HBsAg) and HBeAg. Objective The phase 2 REEF-IT study (NCT04439539) assessed safety, efficacy and pharmacokinetics of pegylated interferon-α2a (PegIFN-α2a) add-on to JNJ-73763989 (JNJ-3989)±bersacapavir+nucleos(t)ide analogues (NA) in not currently treated, HBeAg+chronic hepatitis B.
Design Participants received JNJ-3989 (200 mg every 4 weeks)+NA±bersacapavir (250 mg daily) for 36 - 52 weeks (induction) followed by 12 weeks of PegIFN-α2a (180 µg weekly) add-on. The primary endpoint was the proportion of participants with HBsAg seroclearance 24 weeks after stopping all treatment including NA.
Changes in viral markers, safety and pharmacokinetics were assessed. Results 49/54 (91%) enrolled participants completed the study; 52% were male, with mean age of 33.6 years.
No participant achieved the primary endpoint; one met NA completion criteria. 11/54 (20.4%) participants achieved HBsAg seroclearance at least once, 6 of them maintained it until Follow-up Week 48 (FUW48).
Gut (BMJ) published a clinical update in Research Highlights on 07 Apr 2026.
The item focuses on Peginterferon alpha-2a add-on to siRNA JNJ-73763989 in untreated patients with HBeAg-positive chronic hepatitis B virus (HBV) infection: the phase 2 REEF-IT study.
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