Arrowhead Pharmaceuticals Announces New Phase 2 Data of Plozasiran Published in JAMA Cardiology and Presented at American College of Cardiology 73rd Annual Scientific Session & Expo

Rhea-AI Summary

Arrowhead Pharmaceuticals, Inc. presented final data from the Phase 2 SHASTA-2 study of plozasiran, showing significant reductions in triglycerides and APOC3 in patients with severe hypertriglyceridemia. Promising results led to the initiation of Phase 3 studies SHASTA-3 and SHASTA-4. Plozasiran demonstrated dose-dependent reductions in triglycerides and APOC3, with up to 86% and 90% reductions, respectively, and significant improvements in atherogenic lipoprotein levels. Over 90% of patients achieved triglyceride levels below the pancreatitis risk threshold, and almost half reached normal levels. Safety profile was favorable, with common adverse events like COVID-19 infection and diarrhea.

Positive

• Significant and sustained reductions in triglycerides and APOC3 were observed in the SHASTA-2 study of plozasiran.
• Over 90% of patients achieved triglyceride levels below the pancreatitis risk threshold, and almost half reached normal levels.
• Plozasiran demonstrated a favorable safety profile with common adverse events like COVID-19 infection and diarrhea.
• Phase 3 studies SHASTA-3 and SHASTA-4 are planned to evaluate the efficacy and safety of plozasiran in patients with severe hypertriglyceridemia.

Negative

• None.

Medical Research Analyst

The data from Arrowhead Pharmaceuticals' Phase 2 SHASTA-2 study on plozasiran indicates a substantial reduction in triglycerides and APOC3 levels in patients with severe hypertriglyceridemia (SHTG). The implications of these results are significant for the medical community and potential investors, as SHTG is associated with an increased risk of acute pancreatitis and cardiovascular diseases. The ability of plozasiran to achieve a reduction in triglyceride levels below the threshold for elevated pancreatitis risk in a large percentage of patients could position it as a leading treatment option, addressing an unmet medical need.

From a research perspective, the consistency and durability of the drug's effect, with limited interpatient variability, are particularly noteworthy. These characteristics could translate into a strong value proposition in the competitive landscape of lipid-lowering therapies. The upcoming Phase 3 studies, SHASTA-3 and SHASTA-4, are critical for confirming efficacy and safety in a larger population, which, if successful, could lead to FDA approval and commercialization. The safety profile, as reported, appears favorable, which is an essential factor for both regulatory approval and market acceptance.

Financial Analyst

Arrowhead Pharmaceuticals' announcement regarding the progress of plozasiran may have a positive impact on its stock valuation. The transition into Phase 3 clinical trials represents a significant milestone in the drug development process, often serving as a catalyst for investor interest. Given the high prevalence of SHTG and the limited treatment options currently available, the market potential for plozasiran is considerable. Moreover, the drug's ability to significantly lower triglyceride levels and improve other atherogenic lipid profiles presents a strong case for its differentiation in the market.

Investors will likely monitor the initiation of the Phase 3 studies closely, as these trials could further de-risk the investment proposition. It is also important to consider the broader implications of a successful launch, such as potential partnerships, licensing agreements, or even acquisition interest from larger pharmaceutical companies seeking to expand their cardiometabolic portfolios. The financial health of Arrowhead, including cash flow and burn rate, will be critical as they progress through these capital-intensive late-stage trials.

Cardiologist

The clinical outcomes of plozasiran are promising from a cardiology standpoint, as the management of severe hypertriglyceridemia is a challenging aspect of cardiovascular risk reduction. The drug's efficacy in reducing triglycerides and APOC3, a key regulator of triglyceride metabolism, could have significant implications for patient care. Achieving normal triglyceride levels in nearly half of the patients is particularly impressive and could lead to a reduction in the incidence of pancreatitis and potentially lower the risk of cardiovascular events.

However, long-term data and real-world evidence will be necessary to fully understand the clinical benefits and to integrate plozasiran into treatment guidelines. The cardiovascular community will also be interested in the drug's impact on endpoints such as myocardial infarction, stroke and cardiovascular death in future studies. Additionally, the drug's tolerability and ease of use in a broader patient population will be critical factors for widespread clinical adoption.

- Plozasiran reduced triglycerides and APOC3 up to a mean maximum of 86% and 90% respectively in patients with severe hypertriglyceridemia

- SHASTA-3 and SHASTA-4 Phase 3 studies to be initiated

PASADENA, Calif.--(BUSINESS WIRE)--

Arrowhead Pharmaceuticals, Inc. (NASDAQ: ARWR) today presented final data from the double-blind treatment period of its Phase 2 SHASTA-2 study of investigational plozasiran (formerly ARO-APOC3) in patients with severe hypertriglyceridemia (SHTG). Results from the SHASTA-2 study showed dramatic, consistent, and sustained reductions in Apolipoprotein C-III (APOC3) and triglycerides and improvement in multiple atherogenic lipoprotein levels. These data were presented in a late-breaking oral presentation today at the American College of Cardiology 73^rd Annual Scientific Session & Expo (ACC.24) in Atlanta and simultaneously published in the journal JAMA Cardiology.

“Promising results presented today at ACC.24 and simultaneously published in JAMA Cardiology showed that treatment with plozasiran in the SHASTA-2 study led to significant and sustained reductions in triglyceride levels below the threshold associated with elevated risk for pancreatitis. These are important and exciting data as patients with severe hypertriglyceridemia currently have limited treatment options,” said Daniel Gaudet, M.D., Ph.D., Professor of Medicine at Université de Montréal and Principal Investigator for the SHASTA-2 study.

Select SHASTA-2 Results

Treatment with plozasiran led to dose-dependent placebo-adjusted reductions in triglycerides (primary endpoint) of -49% (P < 0.001), -53% (P < 0.001), and -57% (P < 0.001), driven by placebo-adjusted reductions in APOC3 of -68% (P < 0.001), -72% (P < 0.001), and -77% (P < 0.001) at week 24, after receiving two doses of 10 mg, 25 mg, and 50 mg plozasiran, respectively. Mean maximum, non-placebo adjusted reductions from baseline in triglycerides and APOC3 were up to 86% and 90% and typically occurred around week 16 or week 20.

Significant and durable triglyceride and APOC3 reductions persisted to week 48, 36 weeks after the last dose. There was limited interpatient variability in pharmacodynamic response across all plozasiran treatment groups.

Among patients treated with plozasiran, 90.6% achieved a triglyceride level less than 500 mg/dL, the level associated with increased risk of acute pancreatitis, at week 24. In addition, 48.4% of patients achieved normal triglyceride levels of less than 150 mg/dL at week 24.

Subjects treated with plozasiran also showed improvements in multiple atherogenic lipid and lipoprotein levels, including remnant cholesterol, HDL-cholesterol, and non-HDL cholesterol.

Bruce Given, M.D., interim chief medical scientist at Arrowhead, added, “We continue to be encouraged by the full 48-week data from the SHASTA-2 study of plozasiran in patients with severe hypertriglyceridemia and as a result we are confidently advancing the program into multiple Phase 3 studies. We are pleased that over 90% of patients that received just two doses of plozasiran in the SHASTA-2 study achieved triglyceride levels below the level associated with increased risk of pancreatitis, and almost half of patients achieved triglyceride levels in the normal range, which is surprising given the high mean starting levels of almost 900 mg/dL. Two of Arrowhead’s planned Phase 3 studies are SHASTA-3 and SHASTA-4, which are both pivotal, year-long, placebo-controlled studies to evaluate the efficacy and safety of plozasiran in patients with severe hypertriglyceridemia, the same patient population as SHASTA-2. These studies are both on schedule to begin dosing over the coming months.”

Safety and Tolerability

Plozasiran demonstrated a favorable safety profile in the SHASTA-2 study. The adverse event and serious adverse event profile were similar across treatment groups. Observed adverse events generally reflected the comorbidities and underlying conditions of the study population. All serious treatment emergent adverse events were deemed not related to plozasiran. The most common events occurring in 5 or more patients were COVID-19 infection, worsening glycemic control, diarrhea, urinary tract infection, and headache.

Details about the ACC.24 presentation are listed below.

American College of Cardiology 73rd Annual Scientific Session & Expo – April 6-8, 2024

Title: Plozasiran (ARO-APOC3), An Investigational RNAi Therapeutic, Demonstrates Profound and Durable Reductions in APOC3 and Triglycerides (TG) in Patients With Severe Hypertriglyceridemia (SHTG), SHASTA-2 Final Results
Date/Time: April 7, 2024, 9:00 a.m. EDT
Presenter: Daniel Gaudet MD, PhD
Session: Late-Breaking Clinical Trials II

Slides from the late-breaking oral presentation at ACC.24 may be accessed on the Events and Presentations page under the Investors section of the Arrowhead website after the oral presentation concludes.

About SHASTA-2

SHASTA-2 (AROAPOC3-2001) is a double-blind, placebo-controlled Phase 2b study in adults with SHTG. Three dose levels of plozasiran (10 mg, 25 mg and 50 mg) were evaluated against placebo in 229 participants who had mean fasting triglycerides of greater than or equal to 500 mg/dL (5.65 mmol/L) at screening. Participants were randomly assigned in a 3:1 ratio to receive plozasiran or placebo. Each participant received subcutaneous injections on day 1 and week 12. The duration of the study was approximately 54 weeks from screening to the week 48 end-of-study examination. The primary objective of the study was to evaluate the safety and efficacy of plozasiran in adults with SHTG and to select a dosing regimen for later stage clinical studies in this patient population.

About Severe Hypertriglyceridemia

Severe hypertriglyceridemia (SHTG) is characterized by triglyceride (TG) levels greater than 500 mg/dL^1-3. Very severe forms (TG greater 880 mg/dl) include familial chylomicronemia syndrome (FCS) and multifactorial chylomicronemia syndrome (MCS)^4-6. SHTG significantly increases the risk of atherosclerotic cardiovascular disease (ASCVD) and acute pancreatitis (AP), often with recurrent attacks requiring repeat hospital admissions and worsening outcomes^1-3,6. AP risk is proportional to number, characteristics, and concentration of triglyceride rich lipoproteins (TRLs), particularly chylomicrons, and increases as TGs rise⁷. Limited treatment options exist to sustainably reduce TGs below the pancreatitis risk threshold^1-3.

About Plozasiran

Plozasiran, previously called ARO-APOC3, is a first-in-class investigational RNA interference (RNAi) therapeutic designed to reduce production of Apolipoprotein C-III (APOC3), which is a component of triglyceride rich lipoproteins (TRLs) and a key regulator of triglyceride metabolism. APOC3 increases triglyceride levels in the blood by inhibiting breakdown of TRLs by lipoprotein lipase and uptake of TRL remnants by hepatic receptors in the liver. The goal of treatment with plozasiran is to reduce the level of APOC3, thereby reducing triglycerides and restoring lipids to more normal levels.

In multiple clinical studies, investigational plozasiran demonstrated reductions in triglycerides and multiple atherogenic lipoproteins in patients with familial chylomicronemia syndrome (FCS), severe hypertriglyceridemia (SHTG), and mixed dyslipidemia (MD). Plozasiran has demonstrated a favorable safety profile to date with treatment emergent adverse events reported that reflect the comorbidities and underlying conditions of the study populations. Plozasiran is currently being investigated in the Phase 3 PALISADE clinical study in patients with FCS, which is on schedule to be completed in the middle of 2024. Phase 2 studies in patients with SHTG and MD, SHASTA-2 and MUIR respectively, are complete and additional Phase 3 studies are planned to begin shortly.

Plozasiran has been granted Orphan Drug Designation and Fast Track Designation by the U.S. Food and Drug Administration and Orphan Drug Designation by the European Medicines Agency.

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.

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Source: Arrowhead Pharmaceuticals, Inc.

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1. Pejic RN, et al. J Am Board Fam Med. 2006; 19:310-6.
2. Grundy SM, et al. J Am Coll Cardiol. 2019; 73(24):e285-350;
3. NCEP, ATPIII final report. NIH publication no.: 02–5215, 2002.
4. Christian JB, et al. Am J Cardiol. 2011;107(6):891-897.
5. Fan W, et al. Cardiol Ther. 2020;9(1):207-213.
6. Okazaki H. J Atheroscler Thromb. 2021; 28(9): 883–904;
7. Yang, A.L. et al., Pancreatology, 2020. 20(5): p. 795-800.

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Arrowhead Pharmaceuticals, Inc.

Vince Anzalone, CFA

626-304-3400

ir@arrowheadpharma.com

Investors:

LifeSci Advisors, LLC

Brian Ritchie

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www.lifesciadvisors.com

Media:

LifeSci Communications, LLC

Kendy Guarinoni, Ph.D.

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Source: Arrowhead Pharmaceuticals, Inc.

What were the primary endpoints of the SHASTA-2 study for plozasiran (ARWR)?

The primary endpoint of the SHASTA-2 study for plozasiran was dose-dependent placebo-adjusted reductions in triglycerides.

What percentage of patients achieved triglyceride levels below 500 mg/dL in the SHASTA-2 study of plozasiran (ARWR)?

In the SHASTA-2 study of plozasiran, 90.6% of patients achieved triglyceride levels below 500 mg/dL.

What Phase 3 studies are planned for plozasiran (ARWR) after the SHASTA-2 study?

Arrowhead Pharmaceuticals plans to conduct Phase 3 studies SHASTA-3 and SHASTA-4 to evaluate the efficacy and safety of plozasiran in patients with severe hypertriglyceridemia.

What were the most common adverse events observed in the SHASTA-2 study of plozasiran (ARWR)?

Common adverse events in the SHASTA-2 study of plozasiran included COVID-19 infection, worsening glycemic control, diarrhea, urinary tract infection, and headache.