There have been no serious or severe adverse events reported in any subject. Overall, adverse events have been consistent with those typically seen in normal volunteer studies, including in placebo subjects. The most common events reported were upper respiratory infection (7), which were not unexpected as the trial was enrolled during the Australian winter, and headache (7). The only other events reported in more than one subject were mild lightheadedness (2), which were not accompanied by any changes in vital signs, laboratories or physical examinations. One subject developed an urticarial rash with no other physical findings, and was treated successfully with anti-histamine. Adverse events appear to have been randomly scattered across all six dosing groups with no apparent dose-related increases in occurrence rate or severity with the possible exception of mild lightheadedness. Both subjects with mild lightheadedness were in the 2 mg/kg group. Laboratory abnormalities have occurred sporadically across groups and time points pre- and post-dosing. None of these indicate any organ toxicity and the frequency and severity do not appear to be dose-related.The study remains blinded and follow-up is ongoing. Arrowhead intends to report additional data including pharmacokinetics and relative occurrence rates for adverse events in placebo and ARC-520 treatment groups at an appropriate venue when those data become available. The company plans to use the blinded analysis available now to move forward with a filing seeking approval to proceed with a Phase 2a trial in Hong Kong. About ARC-520 Approximately 350 million people worldwide are chronically infected with the hepatitis B virus. Chronic HBV infection can lead to cirrhosis of the liver and is responsible for 80% of primary liver cancers globally. Arrowhead’s RNAi-based candidate ARC-520 is designed to treat chronic HBV infection by reducing the expression and release of new viral particles and key viral proteins. The goal is to achieve a functional cure, which is an immune clearant state characterized by hepatitis B s-antigen negative serum with or without sero-conversion. The siRNAs in ARC-520 intervene at the point of DNA transcription, upstream of where nucleotide and nucleoside analogues act. In transient and transgenic mouse models of HBV infection, a single co-injection of Arrowhead’s DPC delivery vehicle with cholesterol-conjugated siRNA targeting HBV sequences resulted in multi-log knockdown of HBV RNA, proteins and viral DNA with long duration of effect. In a chimpanzee chronically infected with HBV and high viremia and antigenemia, ARC-520 induced rapid reductions of 90-95% in HBV DNA, e-antigen, and s-antigen. Arrowhead has completed enrollment in a phase 1 single ascending dose study in normal volunteers, which the company expects to follow with a phase 2a study in chronic HBV patients.
About Arrowhead Research CorporationArrowhead Research Corporation is a biopharmaceutical company developing targeted RNAi therapeutics. The company is leveraging its proprietary drug delivery technologies to develop targeted drugs based on the RNA interference mechanism that efficiently silence disease-causing genes. Arrowhead technologies also enable partners to create peptide-drug conjugates that specifically home to cell types of interest while sparing off-target tissues. Arrowhead’s pipeline includes clinical programs in chronic hepatitis B virus and obesity and partner-based programs in oncology. For more information please visit http://www.arrowheadresearch.com, or follow us on Twitter @ArrowRes. To be added to the Company's email list to receive news directly, please send an email to email@example.com Safe Harbor Statement under the Private Securities Litigation Reform Act: This news release contains forward-looking statements within the meaning of the "safe harbor" provisions of the Private Securities Litigation Reform Act of 1995. These statements are based upon our current expectations and speak only as of the date hereof. Our actual results may differ materially and adversely from those expressed in any forward-looking statements as a result of various factors and uncertainties, including our ability to finance our operations, the future success of our scientific studies, our ability to successfully develop drug candidates, the timing for starting and completing clinical trials, rapid technological change in our markets, and the enforcement of our intellectual property rights. Arrowhead Research Corporation's most recent Annual Report on Form 10-K and subsequent Quarterly Reports on Form 10-Q discuss some of the important risk factors that may affect our business, results of operations and financial condition. We assume no obligation to update or revise forward-looking statements to reflect new events or circumstances.