[8-K] ARROWHEAD PHARMACEUTICALS, INC. Reports Material Event

Rhea-AI Filing Summary

Arrowhead Pharmaceuticals, Inc. announced 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), a rare lipid disorder. This marks a significant regulatory milestone for the company, adding an FDA‑approved therapy to its portfolio. Arrowhead also held a conference call to discuss the approval and provided a detailed press release and slide presentation as exhibits to the report.

Positive

• FDA approval of REDEMPLO (plozasiran) for FCS as an adjunct to diet to reduce triglycerides in affected adults represents a major regulatory milestone and potential new revenue source.
• Transition from development to commercial stage for this asset de‑risks Arrowhead’s pipeline in a high‑need rare disease area and may enhance the company’s strategic positioning in lipid disorders.

Negative

• None.

Insights

Biopharma & Regulatory Events Analyst

FDA approval of REDEMPLO for FCS is a major, thesis-changing milestone.

The company reports 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. FDA approval typically allows commercial promotion and prescribing in the United States for the specified use, which can transform a development-stage asset into a marketed product.

Because familial chylomicronemia syndrome is a serious, rare condition, an approved triglyceride-lowering therapy may be strategically important for Arrowhead’s rare disease franchise. The filing notes that Arrowhead issued a press release and hosted a conference call with slides, indicating that management views this as a key event and is providing additional details to the market.

From an investment perspective, the approval is a clear de‑risking event for this specific program and could open a new revenue stream, although actual commercial performance will depend on factors such as pricing, access, and adoption that are not discussed here. Subsequent disclosures in company materials may give more detail on launch plans, collaboration structures, and expected financial impact.

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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, Arrowhead 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						REDEMPLO Approval Conference Call November 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

FAQ

What did Arrowhead Pharmaceuticals (ARWR) announce in this 8-K filing?

Arrowhead Pharmaceuticals announced 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), and that it held a conference call to discuss the approval.

What is REDEMPLO (plozasiran) approved to treat according to Arrowhead’s 8-K?

REDEMPLO® (plozasiran) is approved by the U.S. Food and Drug Administration as an adjunct to diet to reduce triglycerides in adults with familial chylomicronemia syndrome (FCS).

How did Arrowhead Pharmaceuticals communicate the REDEMPLO approval to investors?

Arrowhead issued a press release and held a conference call discussing the FDA approval of REDEMPLO, and it attached the press release as Exhibit 99.1 and the conference call slide deck as Exhibit 99.2.

Does the Arrowhead (ARWR) 8-K specify the regulatory body that approved REDEMPLO?

Yes. The filing states that the U.S. Food and Drug Administration approved REDEMPLO® (plozasiran) for use as an adjunct to diet to reduce triglycerides in adults with FCS.

What type of SEC filing did Arrowhead use to report the REDEMPLO approval?

Arrowhead used a Form 8-K under Item 8.01 Other Events to report the FDA approval of REDEMPLO and to furnish the related press release and conference call slides.

Who signed the Arrowhead Pharmaceuticals 8-K reporting the REDEMPLO approval?

The report was signed on behalf of Arrowhead Pharmaceuticals, Inc. by Daniel Apel, Chief Financial Officer.