Press Release Details

PASADENA, Calif.--(BUSINESS WIRE)--Apr. 11, 2018-- Arrowhead Pharmaceuticals Inc. (NASDAQ: ARWR) today announced the presentation of clinical data on ARC-520, the company’s prior generation investigational medicine for the treatment of chronic hepatitis B infection, at The International Liver Congress™ 2018 (ILC), the annual meeting of the European Association for the Study of the Liver (EASL). An ePoster with these data is now available at ILC and on the company’s website.

The poster presentation includes follow-up data for patients enrolled in the Heparc-2001 multi-dose extension study. In the study, 8 chronic hepatitis patients (5 HBeAg-negative, 3 HBeAg-positive) received up to 9 doses of 4 mg/kg ARC-520 once every 4 weeks with daily entecavir (ETV). Viral DNA, RNA, and antigen knockdown were measured at regular intervals. Patients continued their daily ETV and were monitored for an additional 12 months following the last ARC-520 dose.

Key results include the following:

• One HBeAg-negative patient serocleared HBsAg post ARC-520
• Mild ALT changes off ARC-520 therapy coincided with sustained host responses in 2/3 HBeAg-positive and 2/5 HBeAg-negative patients
• A single dose of ARC-520 in combination with ETV reduced HBsAg for up to 44 weeks
• Multiple doses of ARC-520 resulted in additional HBsAg reductions in all patients by as much 5.3 Log10
• ARC-520 in combination with ETV was effective at rapidly suppressing HBV DNA

Poster Presentation Details:

RNA interference therapy with ARC-520 Injection results in long term off-therapy antigen reductions in treatment naïve, HBeAg positive and negative patients with chronic HBV

• Presentation Reference: FRI-362
• Session: Viral hepatitis B/D: Therapy
• Session Date and Time: April 13, 2018 from 9 a.m. to 5 p.m. CET
• Authors: Man-Fung Yuen, et al.

Additional details, including the presentation abstract, can be found on the ILC website at https://ilc-congress.eu/. A copy of presentation materials can be accessed by visiting the Events section of the Arrowhead website.

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.

For more information, please visit www.arrowheadpharma.com, or follow us on Twitter @ArrowheadPharma. To be added to the Company's email list and receive news directly, please visit http://ir.arrowheadpharma.com/email-alerts.

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 the safety and efficacy of our product candidates, the duration and impact of regulatory delays in our clinical programs, 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.

Source: Arrowhead Pharmaceuticals, Inc.

View source version on businesswire.com: https://www.businesswire.com/news/home/20180411005375/en/

Source: Arrowhead Pharmaceuticals Inc.

Arrowhead Pharmaceuticals, Inc.
Vince Anzalone, CFA
626-304-3400
ir@arrowheadpharma.com
or
Investors and Media:
LifeSci Advisors, LLC
Brian Ritchie, 212-915-2578
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