Efficacy and safety of BLV monotherapy for chronic hepatitis delta: posttreatment results through 48 weeks after the end of treatment from an interim analysis of a randomised Phase 3 study MYR301.

Bulevirtide (BLV) is approved in Europe for chronic hepatitis delta (CHD). MYR301 (NCT03852719) showed BLV 2 d or 10 mg/d monotherapy was efficacious and safe through 144 weeks(w) of treatment. To present MYR301 results through 48w after the end of treatment (EOT; FU48). We randomised 150 patients with CHD (stratified by presence/absence of compensated cirrhosis [CC]) in a 1:1:1 ratio to Arm A: no active anti-hepatitis delta virus (HDV) treatment for 48w followed by BLV 10 mg/d for 96w (n=51), or Arm B: BLV 2 mg/d (n=49) or Arm C: BLV 10 mg/d (n=50) for 144w. Patients were followed for 96w after EOT. Endpoints included combined response (CR) defined as virologic response (VR; undetectable HDV RNA or a decrease by ≥2 log10 IU/mL from baseline) and ALT normalisation, VR, ALT normalisation, undetectable HDV RNA, liver stiffness, and liver-related outcomes. Among patients, 47% had CC; 72% reached FU48. All response rates decreased after EOT due to viral relapses or rebounds, which mainly occurred over the first 24w after EOT. CR and ALT normalisation rates were similar regardless of dose/duration. VR and undetectable HDV RNA rates after EOT were higher with BLV 10 vs 2 mg or delayed treatment. Only 2 liver-related events were reported after EOT: ascites (Arm A) and oesophageal variceal bleed (Arm B). More patients in Arm A had serious adverse events (SAEs) and grade ≥3 AEs after EOT vs Arms B and C. Of 13 patients who reported an SAE that started after EOT, 9 had posttreatment flare with ALT and HDV RNA increases (5/9 cirrhotic). A subset of patients treated with BLV monotherapy for 2-3 years maintained virologic and biochemical responses 1 year after stopping BLV. Liver-related event rates 1 year after completing BLV monotherapy were low. [ABSTRACT FROM AUTHOR]