Arrowhead submits PhIIa application for hep B RNAi candidate

After earlier this month announcing promising new data supporting its genetic treatment for hepatitis B, Arrowhead Research ($ARWR) is moving forward with the candidate. The Pasadena, CA-based company has submitted its application to begin a Phase IIa trial of ARC-520, which uses Arrowhead's polymer-based method to effectively deliver RNAi to the nucleus.

Pending approval of the study, researchers will look to determine the effect of one intravenous dose of ARC-520, in combination with the oral antiviral entecavir, on hepatitis B surface antigen reduction. The trial will take place in Hong Kong, which hosts a high prevalence of chronic hep B infection, the company said Monday.

Arrowhead's investigational therapy uses a unique system to facilitate endosomal escape, in which a "masking" and "unmasking" process allows for the release of genetic material into a cell. The delivery vehicle, dubbed Dynamic Polyconjugates, helps RNA enter the cell unscathed. There, specific siRNA strands can silence the expression of the target gene before making their way out.

The new trial application follows on the heels of successful data from a primate study in which ARC-520 substantially reduced viral DNA, as well as associated antigens, for more than two months. What's more, researchers observed an "immunological flare" they said could lead to antigen conversion and a "functional cure."

While genetic-drug delivery has posed challenges in the past, Arrowhead is not the only company currently making waves in the area. Thanks to clinical and financing successes, companies like Alnylam ($ALNY) and Arcturus have also helped RNAi capability turn a corner with their own novel delivery approaches.

- read the release