Arrowhead Research Corporation (NASDAQ: ARWR), a targeted therapeutics company, will host an analyst event today in New York City to discuss ARC-520, its RNAi-based candidate designed to treat chronic hepatitis B virus infection. The company will discuss the program and describe new preclinical data showing that a low dose of ARC-520 induced rapid and deep reductions in viral particles and key viral antigens in a chimpanzee chronically infected with hepatitis B virus. Arrowhead identified a well-tolerated dose of ARC-520 that lead to a 95% reduction in circulating viral DNA, and approximately 90% reductions in hepatitis e-antigen (HBeAg) and s-antigen (HBsAg), which are thought to be important in establishing a functional cure. These data support previous findings in rodent models and may be predictive of a therapeutic dose range to be identified in upcoming clinical trials expected to start in the middle of this year.
“This is the first time I have tested an siRNA therapy that was efficiently delivered to the liver and suppressed HBV infection including serum levels of HBsAg, a marker that is not suppressed effectively using current therapies,” said Dr. Robert Lanford of the Texas Biomedical Research Institute where the study was conducted. “This was a proof-of-concept study with a novel approach for curing HBV infection and this therapy provided highly promising results in a very short trial.”
The study was designed to test tolerability of a low dose of ARC-520 and its ability to reduce viral load and the key viral proteins, HBsAg and HBeAg, after intravenous administration in a chimpanzee with chronic hepatitis B infection. The animal being treated had exceptionally high titers of circulating HBV DNA and HBsAg that measured 1,000 to 10,000-fold higher than the average chronic hepatitis B patient. The HBV infection has been chronic for over thirty years and has persisted despite prior therapy with multiple anti-viral drugs and therapeutic vaccine exposures.