Arrowhead Pharmaceuticals Reports Inducement Grants under NASDAQ Marketplace Rule 5635(c)(4)

PASADENA, Calif.–(BUSINESS WIRE)–Dec. 17, 2018–
Arrowhead Pharmaceuticals Inc. (NASDAQ: ARWR) today announced that as an
inducement to entering into employment with the Company, on December 7,
2018, the Board of Directors approved “inducement” grants to 3 new
employees under Rule 5635(c)(4) of the NASDAQ Marketplace Rules. The
option grants entitle the employees, in aggregate, to purchase up to
47,000 shares of common stock. The strike price of options is set at an
exercise price per share of $13.66, the last reported closing price of
the Company’s common stock on December 10, 2018, the date of grant,
except for certain shares which will be priced at the last reported
closing price of the Company’s common stock on the date of hire of one
new employee, anticipated to be within 60 days of the date of the
approval. The grants are outside of the Company’s stockholder-approved
equity incentive plans. The options vest and become exercisable over a
period of four years.

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 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.

Source: Arrowhead Pharmaceuticals Inc.

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