Arrowhead Presents Clinical Data on JNJ-3989 (ARO-HBV) at The International Liver Congress™

PASADENA, Calif.–(BUSINESS WIRE)–lt;a href="https://twitter.com/search?q=%24arwr&src=ctag" target="_blank"gt;$arwrlt;/agt; lt;a href="https://twitter.com/hashtag/ILC2019?src=hash" target="_blank"gt;#ILC2019lt;/agt;–Arrowhead Pharmaceuticals, Inc. (NASDAQ: ARWR) today announced the
presentation of clinical data from an ongoing Phase 1/2 study
(AROHBV1001) of JNJ-3989 (formerly ARO-HBV), a third-generation
subcutaneously administered RNA interference (RNAi) therapeutic
candidate being developed as a potential treatment for patients with
chronic hepatitis B virus (HBV) infection, at The International Liver
Congress™ 2019 (ILC), the annual meeting of the European Association for
the Study of the Liver (EASL).

Arrowhead entered into a license agreement in October 2018 with Janssen
Pharmaceuticals, Inc., part of the Janssen Pharmaceutical Companies of
Johnson & Johnson, to develop and commercialize ARO-HBV.

Key results from this interim analysis include the following:

• JNJ-3989 rapidly reduced hepatitis B surface antigen (HBsAg) in
  patients that had 24 weeks or more of HBsAg assay results (n=40) to
  thresholds possibly associated with improved chances of HBsAg
  seroclearance¹ in many patients, after only 3 doses
  • 100% of patients (40 of 40) achieved ≥1.0 Log10 IU/mL HBsAg
    reduction
  • 88% of patients (35 of 40) achieved HBsAg <100 IU/mL
  • 43% of patients (17 of 40) achieved HBsAg <10 IU/mL
  • 13% of patients (5 of 40) achieved HBsAg <1 IU/mL
• JNJ-3989 reduced all measurable viral products, including HBsAg in
  hepatitis B e-antigen (HBeAg) positive or HBeAg negative patients
• JNJ-3989 administered subcutaneously was well tolerated at doses up to
  400 mg in all chronic hepatitis B (CHB) patients in cohorts 2b-11
  (n=56)
  • 168 total doses administered to 56 CHB patients (cohorts 2b
    through 11)
  • No drug related serious adverse events (SAE) reported
    • Unrelated SAE of menorrhagia
    • Unrelated SAE of anxiety/depression
  • All patients received all 3 scheduled doses; No dropouts
  • No dose related pattern of adverse changes in laboratory values
    (e.g. ALT, AST, total bilirubin, creatinine)
  • 17 total AEs at injection site (10% of injections) reported (e.g.
    erythema, tenderness, bruising), all were mild

Oral Presentation Details:

Short term RNA interference (RNAi) therapy in chronic hepatitis B
(CHB) using JNJ-3989 brings majority of patients to HBsAg <100 IU/ml

• Presentation Reference: PS-080
• Session: Parallel session: Hepatitis B – drug development
• Session Date and Time: April 12, 2019 at 5:45 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 under the Investors tab of the Arrowhead website.

AROHBV1001 (NCT03365947)
is a Phase 1/2 clinical study evaluating the safety, tolerability, and
pharmacokinetic effects of single-ascending doses (SAD) of ARO-HBV in
healthy adult volunteers, as well as the safety, tolerability, and
pharmacodynamic effects of multiple-ascending doses (MAD) of ARO-HBV in
patients with chronic HBV.

Hepatitis B infection is a life-threatening viral infection of the
liver, which can cause cirrhosis — scarring of liver tissue — and liver
cancer if the infection becomes chronic. The World Health Organization
cites that hepatitis B is a global public health problem with 257
million people living with the disease, resulting in 887,000 deaths in
2015.² While a preventive vaccine is available, cure rates
for those infected remain low and most patients will endure lifelong
therapy.

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.
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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 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 likelihood and
timing of the receipt of future milestone and licensing fees, the future
success of our scientific studies, our ability to successfully develop
and commercialize 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.

________________

¹ Jeng et al. 2018 Hepatology 68:425-434

² World Health Organization (WHO). Hepatitis B. July 2017.
Available at: http://www.who.int/mediacentre/factsheets/fs204/en/

Contacts

Arrowhead Pharmaceuticals, Inc.
Vince Anzalone, CFA
626-304-3400
ir@arrowheadpharma.com

Investors and Media:
LifeSci Advisors, LLC
Brian Ritchie
212-915-2578
britchie@lifesciadvisors.com
www.lifesciadvisors.com