Boston, MA 10/09/2014 (wallstreetpr) – Arrowhead Research Corp (NASDAQ:ARWR) experimental hepatitis B therapy data disappointed the investors following which the stocks of Arrowhead plummeted more than 40%. In the phase II study conducted, the experimental drug ARC-520 resulted in a 0.3 log reduction in HBsAG when dosed at 2 mg/kg. HBsAG indicates the presence of hepatitis virus in the human body.
The expectations and performance
The treatment result came lower compared to investors expectations. In August, Arrowhead Research Corp (NASDAQ:ARWR) hinted that the reduction from therapy was closer to 1 log. However, the revealed data of 0.3log is much lower than 1-log reduction. The data released on ARC-520 was contained in a later-breaker abstract for AASLD annual meeting. It is scheduled to be held in November. A Phase II study of Arrowhead’s experimental drugARC-520 is ongoing. As of now, Arrowhead is testing with higher doses of ARC-520. It needs to be seen if the higher doses can have a positive impact or not. Arrowhead Research Corp (NASDAQ:ARWR) has yet not disclosed the results from higher doses treatment of ARC-520.
The impact of ARC-520 is seen by measuring the change of HBsAg decline from baseline in percentage terms. The patients who were treated with ARC-520 in cohort 1, mean nadir came at -39% with a mean change of -31% on day 85. The patients who were treated with ARC-520 in cohort 2, mean nadir HBsAg came at – 51%with a mean change of -22% on day 85. If the results in cohort 2 are analyzed, the reduction in HBsAG measured in percentage terms was statistically significant versus placebo for three days through 43 post dose.
For the first time, a reduction in HBsAg resulted through RNA interference has been displayed in chronic HBV patients. A specific formula is used to calculate the change in HBsAg decline from baseline and to convert it into a log reduction.