Arrowhead Pharmaceuticals, Inc. and its subsidiaries (referred to herein collectively as the “Company”) are primarily engaged in developing medicines that treat intractable diseases by silencing the genes that cause them. Using a broad portfolio of RNA chemistries and efficient modes of delivery, the Company’s therapies trigger the RNA interference mechanism to induce rapid, deep and durable knockdown of target genes. RNA interference (“RNAi”) is a mechanism present in living cells that inhibits the expression of a specific gene, thereby affecting the production of a specific protein. The Company’s RNAi-based therapeutics may leverage this natural pathway of gene silencing to target and shut down specific disease-causing genes.


Therapeutic Area	Name	Stage	Product Rights
Cardiometabolic	ARO-APOC3	Phase 2b and Phase 3	Arrowhead
	ARO-ANG3	Phase 2b	Arrowhead
	Olpasiran	Phase 3	Amgen
Pulmonary	ARO-ENAC2	Pre-Clinical	Arrowhead
	ARO-RAGE	Phase 1/2	Arrowhead
	ARO-MUC5AC	Phase 1/2a	Arrowhead
	ARO-MMP7	Phase 1/2a	Arrowhead
Liver	GSK-4532990 (formerly ARO-HSD)	Phase 2	GSK
	Fazirsiran	Phase 3	Takeda and Arrowhead
	JNJ-3989	Phase 2	Janssen
	HZN-457 (formerly ARO-XDH)	Phase 1	Horizon
	ARO-C3	Phase 1/2	Arrowhead
	ARO-PNPLA3 (formerly JNJ-75220795)	Phase 1	Arrowhead
Muscle	ARO-DUX4	Pre-Clinical	Arrowhead
CNS	ARO-SOD1	Pre-Clinical	Arrowhead

The Company operates lab facilities in San Diego, California and Madison, Wisconsin, where its research and development activities, including the development of RNAi therapeutics, take place. The Company’s principal executive offices are located in Pasadena, California.

During the first half of fiscal 2023, the Company continued to develop and advance its pipeline and partnered candidates. Several key recent developments include:

•expanded TRiMTM platform to include an optimized intrathecal administration for central nervous system (CNS) delivery with distribution throughout the brain and in all relevant brain cell types. The first development candidate to utilize this new delivery platform, ARO-SOD1, is anticipated to have a clinical trial

application (CTA) filing in the third quarter of 2023 to begin clinical studies. In preclinical studies, ARO-SOD1 achieved 95% spinal cord tissue mRNA knockdown after a single intrathecal dose in human SOD1 transgenic rats and maintained greater than 80% spinal cord tissue mRNA knockdown three months after a single intrathecal dose in non-human primates;

•dosed the first patient in Takeda’s Phase 3 REDWOOD clinical study of Fazirsiran for the treatment of alpha-1 antitrypsin deficiency associated liver diseases, triggering a $40.0 million milestone payment to the Company which is expected to be paid in the third quarter of fiscal 2023;

•dosed the first patient in GSK’s Phase 2b trial of GSK4532990, formerly called ARO-HSD, an investigational RNAi therapeutic for the treatment of patients with non-alcoholic steatohepatitis (NASH), triggering a $30.0 million milestone payment to the Company which is expected to be paid in the third quarter of fiscal 2023;

•announced that the U.S. Food and Drug Administration (FDA) has granted Fast Track designation to ARO-APOC3 for reducing triglycerides in adult patients with familial chylomicronemia syndrome (FCS). ARO-APOC3 was previously granted Orphan Drug designation by the FDA and the European Union;

◦a dose-dependent reduction in AH50, a marker of alternative complement pathway hemolytic activity, with 91% mean reduction at highest dose tested;

•received notice from Janssen of its decision to voluntarily terminate the Research Collaboration and Option Agreement (the “Janssen Collaboration Agreement”) between the Company and Janssen. The Company regained full rights to ARO-PNPLA3, formerly called JNJ-75220795, upon termination of the Janssen Collaboration Agreement, which took effect on April 7, 2023. ARO-PNPLA3 is in Phase 1 clinical trials that are now being developed by the Company;

•initiated dosing in ARO-MMP7-1001 (NCT05537025), a Phase 1/2a single ascending dose and multiple ascending dose clinical study to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of ARO-MMP7, an investigational RNAi therapeutic designed to reduce expression of matrix metalloproteinase 7 (MMP7) as a potential treatment for idiopathic pulmonary fibrosis (IPF), in up to 56 healthy volunteers and in up to 21 patients with IPF;

•enrolled the first subject in a Phase 1 randomized, placebo-controlled trial to assess the safety tolerability, pharmacokinetics and pharmacodynamics of a development-stage medicine, HZN-457 (formerly ARO-XDH), which is out-licensed to Horizon, triggering a $15.0 million milestone payment to the Company which was paid in the second quarter of fiscal 2023;

•enrolled the first subject in Amgen’s Phase 3 trial of Olpasiran, triggering a $25.0 million milestone payment to the Company which was paid in the second quarter of fiscal 2023;

•entered into a Royalty Purchase Agreement (the “Royalty Pharma Agreement”) with Royalty Pharma Investments 2019 ICAV (“Royalty Pharma”) on November 9, 2022, pursuant to which Royalty Pharma paid $250.0 million upfront (See Note 11 — Liability Related to the Sale of Future Royalties of Notes to Consolidated Financial Statements of Part I, “Item 1. Financial Statements.”);

•announced Topline Results from SEQUOIA Phase 2 Study of Fazirsiran (formerly ARO-AAT) in patients with Alpha-1 Antitrypsin Deficiency-Associated Liver Disease in which;

The interim Consolidated Financial Statements include the accounts of Arrowhead Pharmaceuticals, Inc. and its subsidiaries (wholly-owned subsidiaries and a variable interest entity for which the Company is the primary beneficiary). Subsidiaries refer to Arrowhead Madison, Inc., Visirna Therapeutics, Inc. (“Visirna”), and Arrowhead Australia Pty Ltd. For subsidiaries in which the Company owns or is exposed to less than 100% of the economics, the Company records net loss attributable to noncontrolling interests in its consolidated statements of operations equal to the percentage of the economic or ownership interests retained in such entity by the respective noncontrolling party.

The interim Consolidated Financial Statements have been prepared in conformity with U.S. generally accepted accounting principles (“GAAP”). The financial data of the Company included herein are unaudited. In the opinion of management, all material adjustments of a normal recurring nature have been made to present fairly the Company’s financial position at March 31, 2023 and the results of operations and cash flows for the periods presented. All intercompany transactions and balances have been eliminated. Certain prior period amounts have been reclassified to conform with the current period presentation.

Certain financial information that is normally included in annual financial statements prepared in accordance with GAAP, but that is not required for interim reporting purposes, has been omitted from the accompanying interim consolidated financial statements and related notes. Readers are urged to review the Company’s Annual Report on Form 10-K for the year ended September 30, 2022 for more complete descriptions and discussions. Operating results and cash flows for the six months ended March 31, 2023 are not necessarily indicative of the results that may be expected for the fiscal year ending September 30, 2023.

The Company’s primary sources of financing have been through the sale of its securities, revenue from its licensing and collaboration agreements and the sale of certain future royalties. Research and development activities have required significant capital investment since the Company’s inception and are expected to continue to require significant cash expenditure in the future, particularly as the Company’s pipeline of drug candidates and its headcount have both expanded significantly. Additionally, significant capital investment will be required as the Company’s pipeline matures into later stage clinical trials and as the Company plans to increase its internal manufacturing capabilities.

At March 31, 2023, the Company had $135.0 million in cash and cash equivalents (including $7.3 million in restricted cash), $346.0 million in short-term investments and $78.8 million in long-term investments to fund operations. During the six months ended March 31, 2023, the Company’s cash and cash equivalents and investments balance increased by $77.6 million which was primarily due to the $250.0 million upfront payment received from Royalty Pharma (Note 11) and $40.0 million in milestone payments from Horizon and Amgen, partially offset by cash used to fund its operations.

In total, the Company is eligible to receive up to $3.6 billion in developmental, regulatory and sales milestones, and may receive various royalties on net sales from its licensing and collaboration agreements, subject to the terms and conditions of those agreements. The revenue recognition for these collaboration agreements is discussed further in Note 2.

There have been no changes to the significant accounting policies disclosed in the Company’s most recent Annual Report on Form 10-K for the fiscal year ended September 30, 2022.

There have been no recent accounting pronouncements that have significantly impacted this Quarterly Report on Form 10-Q, beyond those disclosed in the Company’s most recent Annual Report on Form 10-K for the fiscal year ended September 30, 2022.