Arrowhead Added to NASDAQ Biotechnology Index®

PASADENA, Calif.–(BUSINESS WIRE)–

Arrowhead Research Corporation (NASDAQ: ARWR), a biopharmaceutical

company developing targeted RNAi therapeutics, today announced that it

has been selected for addition to the NASDAQ Biotechnology Index

(NASDAQ: NBI) as part of the annual re-ranking which will become

effective prior to market open on Monday, December 21, 2015.

The NASDAQ Biotechnology Index is designed to track the performance of a

set of securities listed on The NASDAQ Stock Market® that are classified

as either biotechnology or pharmaceutical according to the Industry

Classification Benchmark. The NASDAQ Biotechnology Index is calculated

under a modified capitalization-weighted methodology and ranked on an

annual basis. All securities in the NASDAQ Biotechnology Index are

listed on the NASDAQ Global Market or the NASDAQ Global Select Market

and must meet certain eligibility requirements.

For more information about the NASDAQ Biotechnology Index, including

eligibility criteria, visit www.nasdaq.com.

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 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 diseases, and ARC-HIF2 for renal cell carcinoma.

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

or follow us on Twitter @ArrowRes.

To be added to the Company’s email list and receive news directly,

please visit http://ir.arrowheadresearch.com/alerts.cfm.

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.

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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