Arrowhead Pharmaceuticals on Thursday made public select initial data from an early-stage clinical study of a hepatitis B drug it’s developing, sending the company’s stock price (NASDAQ: ARWR) to a four-year high. Arrowhead shared data from a study aimed at evaluating the safety and tolerability of a drug candidate it’s developing to treat chronic hepatitis B virus (HBV). An estimated 257 million people worldwide are living with HBV infection, which can lead to cirrhosis and liver cancer, according to the World Health Organization.