Arrowhead's third-generation RNAi shows initial efficacy against HBV

Arrowhead Pharmaceuticals Inc. (NASDAQ:ARWR) gained $5.29 (38%) to $19.39 Thursday after reporting initial data showing that monthly doses of its third-generation RNAi therapy ARO-HBV reduced circulating HBV surface antigen (HBsAg) in a broad population of patients with chronic HBV infection. The biotech added $465 million in market cap on the data.

The data were from eight patients that received three monthly subcutaneous doses of ARO-HBV in the lowest two dose cohorts of the Phase I/II AROHBV1001 study. The cohorts included both hepatitis B e antigen (HBeAg)-positive patients and harder to treat HBeAg-negative patients, irrespective of prior treatment with nucleoside/nucleotide viral replication inhibitors (NUCs). ...