Arrowhead Pharmaceuticals, Inc. (NASDAQ: ARWR) today announced that three presentations are being made on ARC-520, its investigational medicine for the treatment of chronic hepatitis B infection, at The International Liver Congress™ 2016 (ILC 2016), in Barcelona, Spain, April 13-17, 2016.

Collectively, these presentations demonstrate several important findings from Arrowhead's clinical and nonclinical studies of ARC-520, including the following:
  • ARC-520 and entecavir produced rapid HBV DNA suppression with all hepatitis B e-antigen (HBeAg) positive, treatment naïve patients achieving serum HBV DNA reductions of up to 5.5 log (99.9997%), and all HBeAg negative, treatment naïve patients achieving reductions that put them below the limit of quantitation
  • ARC-520 effectively inhibited HBV cccDNA-derived mRNA with observed viral protein reduction in HBV patients of up to 2.0 log (99%) after a single dose
  • Based on HBsAg epitope profile analysis, poster authors and Arrowhead collaborators had previously identified a predictive hepatitis B surface-antigen (HBsAg) Clearance Profile associated with HBsAg clearance in antiviral therapy cohorts
  • There was a significant association between the development of an HBsAg Clearance Profile and ARC-520 therapy in HBV patients
  • Complexed HBsAg antibodies (anti-HBs) were developed and detected in HBV patients treated with ARC-520, which may represent a recovery of the immune system response
  • After monthly administration of 6-11 doses of ARC-520 in chimpanzees chronically infected with HBV, the ARC-520 target site sequences remained virtually unchanged, indicating that no drug resistance developed during the treatment period

Chris Anzalone, Ph.D., president and CEO of Arrowhead Pharmaceuticals, said: "These are exciting results that continue to show that ARC-520 can reduce the production of HBV viral proteins. We have ongoing multiple-dose and combination studies designed to assess if this will allow the body's natural immune defenses to control the virus and lead to a functional cure."

Copies of the poster presentations are currently available as ePosters to ILC 2016 attendees, and we have also made them available on the Arrowhead website on the Events and Presentations page.

About ARC-520

Arrowhead's RNAi-based candidate ARC-520 is being investigated in the treatment of chronic HBV infection. The small interfering RNAs (siRNAs) in ARC-520 intervene at the mRNA level, upstream of the reverse transcription process where current standard of care nucleotide and nucleoside analogues act. Arrowhead is investigating ARC-520 specifically to determine if it can be used to achieve a functional cure, which is an immune clearant state characterized by hepatitis B s-antigen negative serum with or without seroconversion. Approximately 350-400 million people worldwide are chronically infected with the hepatitis B virus, which can lead to cirrhosis of the liver and is responsible for 80% of primary liver cancers globally. Arrowhead is currently conducting Phase 2b multiple dose and combination studies in chronic HBV patients. In clinical studies to date, the most common reported adverse events in all subjects completing treatment were upper respiratory infection and headache.

About Arrowhead Pharmaceuticals

Arrowhead Pharmaceuticals develops medicines that treat intractable diseases by silencing the genes that cause them. Using a broad portfolio of RNA chemistries and efficient modes of delivery, Arrowhead therapies trigger the RNA interference mechanism to induce rapid, deep, and durable knockdown of target genes. RNA interference, or RNAi, is a mechanism present in living cells that inhibits the expression of a specific gene, thereby affecting the production of a specific protein. Arrowhead's RNAi-based therapeutics leverage this natural pathway of gene silencing. The company's pipeline includes ARC-520 and ARC-521 for chronic hepatitis B virus, ARC-AAT for liver disease associated with alpha-1 antitrypsin deficiency, ARC-F12 for hereditary angioedema and thromboembolic disorders, ARC-LPA for cardiovascular disease, and ARC-HIF2 for renal cell carcinoma.

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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. Our 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.

DYNAMIC POLYCONJUGATES is a trademark of Arrowhead Pharmaceuticals, Inc.

Source: Arrowhead Pharmaceuticals, Inc.

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