0000879407 FALSE 0000879407 2025-11-18 2025-11-18

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT
PURSUANT TO SECTION 13 OR 15(D) OF
THE SECURITIES EXCHANGE ACT OF 1934
November 18, 2025
Date of Report
(Date of earliest event reported)

Arrowhead Pharmaceuticals, Inc.
(Exact name of registrant as specified in its charter)

Delaware |  | 001-38042 |  | 46-0408024
(State or other jurisdiction of incorporation) |  | (Commission File Number) |  | (IRS Employer Identification No.)

177 E. Colorado Blvd, Suite 700, Pasadena, CA 91105
(Address of principal executive offices, including Zip Code)
(626) 304-3400
(Registrant’s telephone number, including area code)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐ | Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)
☐ | Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)
☐ | Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))
☐ | Pre-commencement communications pursuant to Rule 13e-4 (c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:
Title of each class |  | Trading Symbol(s) |  | Name of each exchange on which registered
Common Stock, par value $0.001 per share |  | ARWR |  | The Nasdaq Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).
Emerging growth company ☐
If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 8.01 Other Events
On November 18, 2025, Arro whead Pharmaceuticals, Inc. issued a press release announcing that the U.S. Food and Drug Administration has approved REDEMPLO® (plozasiran) as an adjunct to diet to reduce triglycerides in adults with familial chylomicronemia syndrome (FCS). Arrowhead subsequently held a conference call discussing the approval.
A copy of this press release is attached as Exhibit 99.1 to this Current Report and incorporated herein by reference. A copy of the slides presented at the conference call is attached as Exhibit 99.2 to this Current Report and incorporated herein by reference.
Item 9.01. Financial Statements and Exhibits.
(d) Exhibits

Exhibit No. |  | Description
99.1 |  | Press Release, dated November 18, 2025.
99.2 |  | R E D E M PLO Approval Conf erence Call Nov ember 18, 2025
104 |  | Cover Page Interactive Data File (the cover page tags are embedded within the Inline XBRL document).

SIGNATURES
Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.
Date: November 18, 2025

ARROWHEAD PHARMACEUTICALS, INC.
By: |  | /s/ Daniel Apel
|  | Daniel Apel
|  | Chief Financial Officer