Longview

What: Shares of Arrowhead Research Corp. (NASDAQ:ARWR), a clinical-stage biopharma specializing in RNAi therapeutics, rose by as much as 38% today on tremendous volume.

This dramatic spike in Arrowhead's share price was triggered by a positive clinical update from the company for its experimental hepatitis B treatment, ARC-520, that is currently being studied in an ongoing mid-stage trial.

Per the company's press release, a group of treatment-naive, hepatitis B virus E-antigen positive patients that were given a single 4 mg/kg dose of ARC-520 saw a peak reduction in the hepatitis surface antigen, HBsAg, of 99%. Additionally, patients presently on a standard form of background therapy and treated with the same dosage of ARC-520, exhibited a mean maximal reduction of 92% in circulating HBeAg. 

Put simply, the therapy essentially cleared the signs of an active hepatitis B infection in some cases. These preliminary trial results were disclosed by the company as part of its analyst day being held in New York today. 

So what: According to the World Health Organization, 240 million people globally are chronically infected with hepatitis B, resulting in approximately 650,000 deaths every year. While there are a handful of approved products that are effective at preventing infection, or suppressing the virus in infected patients, a functional cure is presently lacking. Arrowhead is hoping ARC-520 can fill this unmet medical need. 

Now what: We should learn further details of ARC-520's mid-stage study at today's presentation for analysts. Nonetheless, I'm personally content sitting on the sidelines with this speculative biopharma stock for the time being. After all, ARC-520 still has a long road ahead of it before going up for a formal regulatory review.  

 

George Budwell has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.