Arrowhead Receives Regulatory Clearance for ARC-AAT Phase 1 in the United Kingdom and New Zealand

PASADENA, Calif.–(BUSINESS WIRE)–

Arrowhead Research Corporation (NASDAQ: ARWR), a biopharmaceutical

company developing targeted RNAi therapeutics, today announced that it

received regulatory permission in the United Kingdom and New Zealand to

proceed with Part B of its Phase 1 study of ARC-AAT, Arrowhead’s

RNAi-based drug candidate for the treatment of liver disease associated

with the rare genetic disorder alpha-1 antitrypsin deficiency (AATD).

The Phase 1 study is currently enrolling patients at a single center in

Australia and, pending approval from ethics committees, the company

intends to begin recruiting patients at additional sites in the United

Kingdom and New Zealand. Arrowhead expects to complete enrollment by the

end of 2015.

The ongoing Phase 1 trial of ARC-AAT is a multi-center, randomized,

placebo-controlled, double-blind, single dose-escalation, first-in-human

study to evaluate the safety, tolerability and pharmacokinetics of

ARC-AAT and the effect on circulating AAT levels. The study has been

enrolling in dose cohorts of six participants each, with participants

randomized at a ratio of 2:1 (active:placebo) to receive a single

intravenous injection of either ARC-AAT or placebo (normal saline). The

study consists of two parts; Part A in healthy volunteers, which has

been completed, and Part B to be conducted in patients with PiZZ

genotype AATD. Dosing in patients begins at the highest dose level used

in healthy volunteers and then continued dose escalation may proceed

under the protocol. The study evaluates participants for 28 days

following dosing, with additional follow-up if needed every 2 weeks

until AAT levels return to baseline.

About ARC-AAT

Arrowhead’s ARC-AAT is being investigated for the treatment of liver

disease associated with Alpha-1 Antitrypsin Deficiency (AATD), a rare

genetic disease that severely damages the liver and lungs of affected

individuals. The mean estimated prevalence of AATD in the U.S is 1 per

3000-5000, or approximately 100,000 patients. AATD is also an important

cause of pediatric liver disease with an estimated prevalence in

children of approximately 20,000 patients, and 50-80% likely to manifest

liver disease during childhood. It is a rare disease that appears to be

frequently misdiagnosed or undiagnosed. ARC-AAT, which was granted

orphan drug designation, employs a novel unlocked nucleobase analog

(UNA) containing RNAi trigger molecule designed for systemic delivery

using the Dynamic Polyconjugate delivery system. ARC-AAT is

highly effective at knocking down the Alpha-1 antitrypsin (AAT) gene

transcript and reducing the hepatic production of the mutant AAT (Z-AAT)

protein in animals. Reduction of liver production of the inflammatory

Z-AAT protein, which is believed to be the cause of progressive liver

disease in AATD patients, is important as it is expected to halt the

progression of liver disease and potentially allow fibrotic tissue

repair. Arrowhead is conducting a single dose Phase 1 clinical study of

ARC-AAT, with part A in healthy volunteers and part B in AATD patients.

About Arrowhead Research Corporation

Arrowhead Research Corporation is a biopharmaceutical company developing

targeted RNAi therapeutics. The company is leveraging its proprietary

Dynamic Polyconjugate delivery platform to develop targeted

drugs based on the RNA interference mechanism that efficiently silences

disease-causing genes. Arrowhead’s pipeline includes ARC-520 for chronic

hepatitis B virus and ARC-AAT for liver disease associated with Alpha-1

antitrypsin deficiency.

For more information please visit http://www.arrowheadresearch.com,

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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. 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.

DYNAMIC POLYCONJUGATES is a trademark of Arrowhead Research

Corporation.

Source: Arrowhead Research Corporation

Arrowhead Research Corporation
Vince Anzalone, CFA
626-304-3400
ir@arrowres.com
or
Investor

Relations:
The Trout Group
Todd James
646-378-2926
ir@arrowres.com
or
Media:
Russo

Partners
Matt Middleman, M.D.
212-845-4272
matt.middleman@russopartnersllc.com

Source: Arrowhead Research Corporation

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