Arrowhead Pharmaceuticals Presents New Positive Clinical Cardiometabolic Data at the 94th European Atherosclerosis Society (EAS) Congress

- New data support potential use of plozasiran without dose adjustment in patients with moderate-to-severe renal or moderate hepatic impairment

- Case report suggests that preconception exposure to plozasiran may be associated with sustained lowering of fasting triglyceride levels throughout the term of a pregnancy

PASADENA, Calif.--(BUSINESS WIRE)--May 26, 2026-- Arrowhead Pharmaceuticals, Inc. (NASDAQ: ARWR) today presented new positive clinical data for plozasiran supporting its use in patients with moderate-to-severe renal impairment or moderate hepatic impairment without the need for dose adjustment, and a case report suggesting that preconception exposure to plozasiran may be associated with sustained lowering of fasting triglyceride (TG) levels through the term of a pregnancy. The data were presented in two oral presentations at the 94^th European Atherosclerosis Society (EAS) Congress, taking place in Athens, Greece from May 24-27.

“Patients living with extremely high triglycerides often suffer from significant comorbidities. Today’s data represent an important step in bridging the gap between patient needs and scientific innovation,” said Jennifer Hellawell, MD, board-certified cardiologist and Vice President of Clinical Development at Arrowhead Pharmaceuticals. “As a physician at heart, I’m proud to be part of the team advancing next-generation therapies for this underserved community. We’re excited to have better characterized the PK and PD of plozasiran in this potentially broader patient population. These data bring us closer to delivering meaningful impact for patients.”

Plozasiran is a small interfering RNA (siRNA) medicine designed to reduce hepatic production of apolipoprotein C‑III (APOC3) through targeted RNA interference. It received regulatory approval in the United States, China, Australia, and Canada as an adjunct to diet to reduce triglycerides in adults with familial chylomicronemia syndrome (FCS) and is currently being investigated in patients with severe hypertriglyceridemia (sHTG). Patients with FCS and sHTG often present with hepatic steatosis or renal impairment. Because the safety and tolerability of plozasiran in the setting of hepatic and/or renal impairment remains unknown, this study assessed the impact of hepatic or renal impairment on the pharmacokinetics, pharmacodynamics, and safety of a single 25 mg dose of plozasiran.

Despite modest increases in plozasiran exposure, PD responses (APOC3 and TG reduction) were similar between control cohorts and those with moderate-to-severe renal or moderate hepatic impairment. In addition, plozasiran was generally safe and well-tolerated, with no new safety signals identified. Together, these data support the use of 25 mg plozasiran in patients with moderate-to-severe renal impairment or moderate hepatic impairment without dose adjustment. Future trials are needed to help further evaluate plozasiran safety in patients with advanced liver or renal disease.

In an additional oral presentation, the company highlighted a patient case report that suggests that preconception exposure to plozasiran may be associated with sustained lowering of fasting TG levels throughout the term of a pregnancy, representing the second case report published on FCS patients in the PALISADE study who discontinued use of plozasiran prior to conception and achieved successful pregnancies. While additional data are needed to define the safety and efficacy of APOC3–targeted therapies during pregnancy, these findings are consistent with the prolonged pharmacodynamic effects of APOC3 inhibition reported in previous PALISADE studies.

Presentation Details:

Session Title: Late Breaking Clinical Abstracts
Title: Pharmacokinetics, Pharmacodynamics, and Safety of Plozasiran in Subjects with Renal or Hepatic Impairment
Date & Time: Tuesday, May 26^th, 3:45 - 5:15PM EEST
Presenting Author: Jennifer Hellawell, MD

Session Title: EAS Stage, Outreach and Case Presentations
Title: A Case Report of a Pregnant Woman with Familial Chylomicronemia Syndrome Treated with Plozasiran, a Small Interfering RNA Against APOC3
Date & Time: Tuesday, May 26^th, 8:30 - 10:30AM EEST
Presenting Author: Ann Mertens, MD

Today’s presentations will be made available on the EAS Conference website and on the Events and Presentations page under the Investors section of the Arrowhead website.

About REDEMPLO^® (plozasiran)

REDEMPLO (plozasiran) is the first and only siRNA treatment approved in these countries that has been studied in both genetically confirmed and clinically diagnosed patients living with FCS. REDEMPLO is a first-in-class siRNA therapeutic designed to suppress the production of apoC-III, a protein produced in the liver that raises triglyceride levels by slowing their breakdown and clearance. By targeting apoC-III with sustained silencing, REDEMPLO delivers significant reductions in triglyceride levels. REDEMPLO is self-administered via subcutaneous injection once every three months.

The EMA CHMP has adopted a positive opinion recommending the European Marketing Authorization of REDEMPLO (plozasiran), which is already approved by the U.S. Food and Drug Administration, Health Canada, the Australian Therapeutic Goods Administration, and China’s National Medical Products Administration as an adjunct to diet to reduce triglycerides for adults with Familial Chylomicronemia Syndrome (FCS).

Plozasiran is also being investigated in the SHASTA-3 (NCT06347003), SHASTA-4 (NCT06347016), and SHASTA-5 (NCT06880770) Phase 3 studies in adults with severe hypertriglyceridemia and the MUIR-3 (NCT06347133) Phase 3 study in adults with hypertriglyceridemia. In December 2025, plozasiran was granted Breakthrough Therapy designation by the U.S. FDA in severe hypertriglyceridemia.

For more information about REDEMPLO, visit Our Medicines.

About Arrowhead Pharmaceuticals

Arrowhead Pharmaceuticals (NASDAQ: ARWR) is a commercial-stage pharmaceutical company developing medicines that treat intractable diseases by silencing the genes that cause them, harnessing the natural RNA interference (RNAi) mechanism. The company has built a broad portfolio of clinical and commercial RNAi therapeutics through its industry-leading targeted RNAi molecule (TRiM™) platform, which can precisely silence genes in a wide range of cell types, including liver, lung, muscle, adipose, and central nervous system tissue. At Arrowhead, we rapidly advance potential best- and first-in-class RNAi treatments for diseases with significant unmet medical need, because every day matters to the patients we serve.

For more information, please visit www.arrowheadpharma.com, or follow us on X (formerly Twitter) at @ArrowheadPharma, LinkedIn, Facebook, and Instagram. 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. Any statements contained in this release except for historical information may be deemed to be forward-looking statements. Without limiting the generality of the foregoing, words such as “may,” “will,” “expect,” “believe,” “anticipate,” “hope,” “intend,” “plan,” “project,” “could,” “estimate,” “continue,” “target,” “forecast” or “continue” or the negative of these words or other variations thereof or comparable terminology are intended to identify such forward-looking statements. In addition, any statements that refer to projections of our future financial performance, trends in our business, expectations for our product pipeline, products or product candidate or other characterizations of future events or circumstances are forward-looking statements. These forward-looking statements include, but are not limited to, statements about our beliefs and expectations regarding the long-term impacts of REDEMPLO^® (plozasiran) on patient health and the health care system; our beliefs and expectations regarding the pricing, value, or expected timing for availability of our drugs and drug candidates; and our believes and expectations around the potential uses and value of the TRiM™ platform. These statements are based upon our current expectations and speak only as of the date hereof. Actual results or outcomes may differ materially and adversely from those expressed in any forward-looking statements as a result of numerous factors and uncertainties the safety and efficacy of our products and product candidates, pricing and reimbursement decisions related to our products, demand for our products, decisions of regulatory authorities and the timing thereof, 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, the timing for starting and completing clinical trials, rapid technological change in our markets, the enforcement of our intellectual property rights, and the other risks and uncertainties described in our most recent Annual Report on Form 10-K, subsequent Quarterly Reports on Form 10-Q and other documents filed with the Securities and Exchange Commission from time to time. We assume no obligation to update or revise forward-looking statements to reflect new events or circumstances.

Source: Arrowhead Pharmaceuticals, Inc.

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Arrowhead Pharmaceuticals, Inc.
Vince Anzalone, CFA
+1 626-304-3400
ir@arrowheadpharma.com

Investors:
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Media:
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Source: Arrowhead Pharmaceuticals, Inc.