Arrowhead Shares Pop on Early Clinical Data for Hepatitis B Drug

Xconomy Wisconsin — 

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.

The data released Thursday come from a Phase 1/2 study testing Arrowhead drug ARO-HBV. The clinical trial is enrolling 60 patients, randomized to receive the injectable Arrowhead drug or a placebo.

Arrowhead released data for eight patients who received the two lowest doses of its drug. In those patients, the company says the drug was able to significantly reduce amounts of hepatitis B surface antigen, a particular protein found in the blood of those who have HBV. The antigen is an HBV protein indicating someone is infectious and can spread the virus to others.

One group of patients, who received a 100mg dose of the experimental drug, experienced an average reduction of 99 percent in circulating HBsAg 85 days after they were dosed. Another group, who received a 200mg dose of ARO-HBV, experienced an average reduction of 96 percent in circulating HBsAg 71 days after being treated with the drug. Those percentages could increase with the passage of time, Arrowhead says. The most common side effects Arrowhead reported were reactions at the site of the injections.

Despite the small patient sample, Wall Street appeared pleased with the study data Arrowhead shared. Shares in the company were trading at $19.39 apiece when the closing bell rang Thursday, an increase of more than 37 percent over the previous day’s close of $14.10 a share. The last time Arrowhead’s stock price closed the trading day above $16 a share was in September 2014.

Arrowhead is among the drug developers seeking to commercialize therapies using RNA interference (RNAi), which involves shutting down, or “silencing” a gene before it can produce a potentially harmful protein. Arrowhead said last December that its goal with ARO-HBV is to mute the production of all HBV genes so that a patient’s immune system can recover.

Arrowhead is developing ARO-HBV using a new type of RNAi drug delivery platform that it first discussed publicly a year ago. It’s using the platform—known as Targeted RNAi Molecule, or TRiM—to develop drugs for chronic HBV, cardiovascular disease, and other conditions.

Madhu Kumar, who researches and analyzes the performance of healthcare companies for investment bank B. Riley FBR, said in a research note that “while early, we believe these findings provide clinical proof of concept for [Arrowhead’s] current HBV RNAi franchise,” according to a MarketWatch report.

Arrowhead said Bruce Given, the company’s chief operating officer, will present data from the ARO-HBV study on Friday at the World Gastroenterologists Summit in Auckland, New Zealand.

Arrowhead is based in Pasadena, CA. Its research and development operations are headquartered in Madison, WI.