Arrowhead Pharmaceuticals Inc. (NASDAQ: ARWR) today announced the presentation of clinical data on ARC-520, the company’s prior generation investigational medicine for the treatment of chronic hepatitis B infection, at The International Liver Congress™ 2018 (ILC), the annual meeting of the European Association for the Study of the Liver (EASL). An ePoster with these data is now available at ILC and on the company’s website.

The poster presentation includes follow-up data for patients enrolled in the Heparc-2001 multi-dose extension study. In the study, 8 chronic hepatitis patients (5 HBeAg-negative, 3 HBeAg-positive) received up to 9 doses of 4 mg/kg ARC-520 once every 4 weeks with daily entecavir (ETV). Viral DNA, RNA, and antigen knockdown were measured at regular intervals. Patients continued their daily ETV and were monitored for an additional 12 months following the last ARC-520 dose.

Key results include the following:

  • One HBeAg-negative patient serocleared HBsAg post ARC-520
  • Mild ALT changes off ARC-520 therapy coincided with sustained host responses in 2/3 HBeAg-positive and 2/5 HBeAg-negative patients
  • A single dose of ARC-520 in combination with ETV reduced HBsAg for up to 44 weeks
  • Multiple doses of ARC-520 resulted in additional HBsAg reductions in all patients by as much 5.3 Log10
  • ARC-520 in combination with ETV was effective at rapidly suppressing HBV DNA