Attralus Presents New Data on Its Pan-Amyloid Diagnostic Imaging Candidates at ASNC 2025

• ¹²⁴I-evuzamitide, the first pan-amyloid diagnostic imaging agent, demonstrated 100% sensitivity and specificity for the diagnosis of cardiac amyloidosis in patients suspected of or diagnosed with cardiac amyloidosis in ATTR, AL, and other rare types of systemic amyloidosis.
• ¹²⁴I-evuzamitide PET/MRI repeat imaging demonstrated consistency with clinical disease course over ~12 months in patients with cardiac amyloidosis
• Phase 3 REVEAL study with ¹²⁴I-evuzamitide in patients with suspected cardiac amyloidosis is ongoing
• AT-05 (^99mTc-p5+14), a pan-amyloid radiotracer, designed for SPECT imaging, demonstrated high levels of sensitivity and specificity for detection of cardiac amyloid in AL and ATTR patients

NAPLES, Fla., Sept. 08, 2025 (GLOBE NEWSWIRE) — Attralus, Inc., a clinical stage biopharmaceutical company developing transformative medicines and diagnostics to improve the lives of patients with systemic amyloidosis, announced five poster presentations and two oral presentations (from investigator-initiated trials), on the use of ¹²⁴I-evuzamitide and AT-05 (^99mTc-p5+14) , the company’s pan-amyloid binding diagnostic imaging agents in development for the diagnosis of systemic amyloidosis, at the American Society of Nuclear Cardiology Annual Scientific Session & Exhibition (ASNC) held in Orlando, FL on September 4–7, 2025.

“Diagnosing patients early remains one of the biggest unmet needs for systemic amyloidosis patients, with many going years without an accurate diagnosis. Current diagnostic methods focus on transthyretin amyloidosis and may not accurately detect early infiltration of amyloid deposits,” said Ahmad Masri, M.D., Associate Professor of Medicine and Cardiomyopathy Section Head at Oregon Health & Science University. “In our PET/MR study, in 111 patients, we were able to show 100 percent sensitivity and specificity for detection of cardiac amyloid in ATTR, AL, and other rare types of systemic amyloidosis patients, including in very early patients. In addition, we demonstrated the ability of ¹²⁴I-evuzamitide to detect extracardiac amyloid and to monitor changes in amyloid load over time with repeated measures. We have been impressed by the results to date and are very much looking forward to the results of the ongoing Phase 3 REVEAL study in suspected cardiac amyloidosis patients. We are excited by the potential of ¹²⁴I-evuzamitide to become a new standard of care for diagnosing and monitoring of systemic amyloidosis.”

“Detection and quantification of amyloid burden in the heart is an unmet clinical need for patients with diverse types of systemic amyloidosis,” said Jonathan Wall, Ph.D., Distinguished Professor, University of Tennessee Graduate School of Medicine. “AT-05 is a promising new reagent for the detection of ATTR and AL cardiac amyloid using planar gamma or SPECT imaging and may serve as a useful tool for the early detection of cardiac and extracardiac amyloid in the community setting for healthcare professionals that have limited access to PET imaging scanners.

“We are excited about the promise of both ¹²⁴I-evuzamitide and AT-05 to impact the lives of systemic amyloidosis patients by potentially diagnosing them earlier and more accurately than current standard of care. Patients receive the most benefit from new therapeutics if given early in the disease process and early diagnosis with ¹²⁴I-evuzamitide could lead to better outcomes for patients. We are excited about the progress of the ongoing REVEAL phase 3 study and look forward to the results in early 2026,” said Spencer Guthrie, Chief Operating Officer, Attralus.

Oral Presentations –

Abstract Title: Diagnostic Performance of Cardiac and Whole-Body 124I-evuzamitide (AT-01) PET/MRI in Systemic Amyloidosis

• Presenter: Ahmad Masri, M.D., Oregon Health and Science University (OHSU)
• Date/Time: September 5, 2025, 4:45 – 5:45 p.m. EDT
• Key Findings:
  • 111 patients were enrolled in the study. Of these, 77 had cardiac transthyretin amyloidosis, 22 had cardiac light chain amyloidosis, 3 had AApoAI or AApoAIV, 10 had systemic amyloidosis but no cardiac involvement, and 24 had no evidence of systemic amyloidosis.
  • ¹²⁴I-evuzamitide PET/MRI had 100% sensitivity and specificity in detecting cardiac amyloidosis in all amyloidosis types. No false positive or false negative cases were observed.
  • Demonstrated evidence of extracardiac uptake in AL, ATTRv and ATTRwt patients, including the kidney, liver, lungs, spleen and musculoskeletal.
  • Demonstrated evidence of ¹²⁴I-evuzamitide uptake in biopsy proven ATTRwt patients with negative PYP bone scintigraphy and a cardiac MRI not suggestive of amyloid.
  • ¹²⁴I-evuzamitide was safe without any serious adverse events.
  • Time from ¹²⁴I-evuzamitide injection to whole-body PET was 3.3 ±0.5 hours.

Abstract Title: A Tale of Two Tracers – A Qualitative Comparison of the PET and SPECT Amyloid-Imaging Agents, ¹²⁴I-evuzamitide (AT-01) and ^99mTc-p5+14 (AT-05), that are Derived from the Same Synthetic Amyloid-Binding Peptide, p5+14

• Presenter: Jonathan S. Wall, University of Tennessee Graduate School of Medicine, Knoxville, TN
• Date/Time: September 5, 2025, 4:45 – 5:45 p.m. EDT
• Key Findings:
  • ¹²⁴I-evuzamitide and ^99mTc-p5+14 are both novel amyloid-reactive peptide radiotracers enabling noninvasive detection of cardiac and systemic amyloid.
  • PET/CT imaging with ¹²⁴I-evuzamitide may yield higher resolution and quantitative data, whereas ^99mTc-p5+14 imaging may prove to be simpler and more accessible.
  • The PET tracer has demonstrated excellent sensitivity in clinical trials and is in a Phase 3 study, whereas the SPECT agent has shown promising early clinical results.
  • Together, they serve as tools that offer complementary strengths: one for detailed quantification in specialized centers, the other for widespread screening and routine practice.

Poster Presentations –

Abstract Title: Temporal Changes in Cardiac Amyloidosis Using 124I-evuzamitide PET/MRI Imaging

• Presenter: Ahmad Masri, M.D., Oregon Health and Science University (OHSU)
• Date/Time: September 5, 2025, 3:45 – 4:45 p.m. EDT
• Key Findings:
  • 21 patients (16 AL, 5 ATTR) had a ¹²⁴I-evuzamitide PET/MRI baseline scan and a repeat scan ~ 12 months later.
  • Patients were on standard of care therapy for cardiac amyloidosis.
  • The change in mean Left Ventricular (LV) Standard uptake value ratio (SUVR) trended with the change in ECV and NT-proBNP but not LVM.
  • The change in max LV SUVR trended with the change in ECV, NT-proBNP and LVM.
  • Minimal clinical changes were observed in patients, which was well captured by stable 124I-evuzamitide uptake.

Abstract Title: Accurate Quantitation of Cardiac Amyloidosis by 124I-Evuzamitide Compared to Extracellular Volume

• Presenter: Alyssa de Moraes, Brigham and Women’s Hospital (BWH)
• Date/Time: September 4, 2025, 5:35 – 6:25 p.m. EDT
• Key Findings:
  • 124I-evuzamitide PET/CT showed mild cardiac uptake and extensive hepatic uptake contrasted with healthy control data
  • Hepatic AL amyloidosis was diagnosed by international criteria of liver enlargement, elevated alkaline phosphatase (>1.5 times normal limits), and absence of heart failure in a patient with biopsy proven AL amyloidosis.
  • This case underscores the value of ¹²⁴I-evuzamitide PET/CT, a novel pan-amyloid binding radiotracer, for diagnosing hepatic AL amyloidosis and avoiding organ biopsy.

Abstract Title: Exploring cardiac uptake of the SPECT radiotracer, ^99mTc-p5+14 (AT-05), in patients with amyloidosis – Significant correlations exist between structural or functional parameters and signal-to-background measurements.

• Presenter: R. Eric Heidel, University of Tennessee Graduate School of Medicine, Knoxville, TN
• Date/Time: September 5, 2025, 3:45 – 4:45 p.m. EDT
• Key findings:
  • The ^99mTc-p5+14 planar heart-to-lung uptake ratio in ATTR patients correlated significantly with NT-proBNP and global longitudinal strain measurements.
  • Significant positive linear correlations were observed between the SPECT uptake ratio of ^99mTc-p5+14 and the cardiac interventricular septum and left ventricular wall thickness, and serum NT-proBNP.
  • The preliminary data supports further evaluation of ^99mTc-p5+14 imaging for detecting cardiac amyloid and its relationship with other measures of amyloid-associated cardiac dysfunction.

Abstract Title: Extracardiac uptake of the SPECT/CT imaging agent, ^99mTc-p5+14 (AT-05), in patients with AL or ATTR cardiac amyloidosis

• Presenter: Emily B. Martin, University of Tennessee Graduate School of Medicine, Knoxville, TN
• Date/Time: September 5, 2025, 3:45 – 4:45 p.m. EDT
• Key Findings:
  • No cardiac uptake of ^99mTc- p5+14 was seen in healthy subjects (100% negative percent agreement; 5/5).
  • Cardiac amyloid was readily imaged in patients with AL or ATTR amyloidosis (94% positive percent agreement; 15/16).
  • In ATTR patients, ^99mTc-p5+14 was observed in focal lesions and pleura of the lungs as well as joints. In patients with cardiac AL amyloidosis, tracer uptake was observed in the lung, liver, spleen, salivary glands, thyroid gland, and tongue.

Abstract Title: ^99mTc-p5+14 (AT-05) is a pan-amyloid imaging agent that effectively detects cardiac amyloid by both planar and SPECT/CT imaging at 1 h post-injection with a high signal-to-background ratio

• Presenter: Jonathan S. Wall, University of Tennessee Graduate School of Medicine, Knoxville, TN
• Date/Time: September 5, 2025, 3:45 – 4:45 p.m. EDT
• Key Findings:
  • Patients with cardiac amyloidosis had significant uptake of ^99mTc-p5+14 in the heart, evidenced in planar and SPECT/CT images acquired at 1 h pi.
  • No cardiac uptake of ^99mTc-p5+14 was observed in healthy subjects.
  • In planar images at 1 h pi, the heart:lung ratio for ^99mTc-p5+14 was greater in patients versus healthy subjects (p<0.0001) and patient ^99mTc-PYP images (p=0.0303).
  • Cardiac uptake of ^99mTc-p5+14 assessed from SPECT/CT images was significantly higher than that of ^99mTc-PYP in ATTR patients (p=0.0009) and of ^99mTc-p5+14 in healthy subjects (p<0.0001).

For additional information, please visit the ASNC 2025 website.
To view posters and presentations, visit the Attralus website.

About ¹²⁴I-evuzamitide (AT-01) Pan-Amyloid Diagnostic
¹²⁴I-evuzamitide is the first non-invasive pan-amyloid PET imaging agent specifically designed for systemic amyloidosis. ¹²⁴I-evuzamitide utilizes the company’s pan-amyloid binding peptide labeled with iodine-124 as an amyloid-specific radiotracer to detect all types of systemic amyloidosis by PET/CT imaging. In clinical trials, ¹²⁴I-evuzamitide has been observed to detect multiple types of amyloid deposits, including ATTR and AL, in major organs such as the heart, kidney, liver, and spleen. Orphan drug designations have been granted to ¹²⁴I-evuzamitide as a diagnostic for the management of ATTR and AL amyloidosis by both the Food and Drug Administration (FDA) and the European Commission.

About Phase 3 REVEAL Study
Research with ¹²⁴I-EVuzamitide to Elucidate Cardiac AmyLoidosis (REVEAL) study is an ongoing Phase 3 clinical trial of the investigational diagnostic imaging agent ¹²⁴I-evuzamitide in patients with suspected cardiac amyloidosis by Brigham and Women’s Hospital in Boston, MA. The trial is designed to determine the sensitivity and specificity of ¹²⁴I-evuzamitide imaging to diagnose cardiac amyloidosis.

About AT-05, Pan-Amyloid Diagnostic
AT-05 uses the same pan amyloid binding peptide as ¹²⁴I-evuzamitide but is labelled with technetium-99m (Tc-99m, ^99mTc). AT-05 is designed to be used with single-photon emission computerized tomography (SPECT) to be more accessible to community cardiologists and thereby support broader screening of systemic amyloidosis. AT-05 is currently in a Phase 1 clinical trial.

About Systemic Amyloidosis
Systemic amyloidosis encompasses a diverse group of rare diseases that occur due to accumulation of toxic amyloid deposits in tissues and organs, a consequence of aberrant protein misfolding events. These diseases are progressive, debilitating and often fatal. The majority of systemic amyloidosis patients have cardiac involvement, including the two most common forms, with ~95 percent of ATTR and 75% of AL patients having cardiac involvement. Other rare types of systemic amyloidosis such as AA, AApoAI, AApoAIV also have cardiac involvement. Cardiac amyloidosis is significantly underdiagnosed due to low awareness, non- specific symptoms, and lack of disease-specific diagnostics. There remains a significant unmet need for better diagnostics that may be able to more accurately diagnose patients earlier in the disease process.

About Attralus
Attralus is a clinical stage biopharmaceutical company focused on creating transformative medicines and diagnostics to improve the lives of patients with systemic amyloidosis. The company’s proprietary pan-amyloid removal (PAR) therapeutics are designed to directly bind to and remove toxic amyloid in organs and tissues. By targeting the disease-causing pathology in systemic amyloidosis diseases, PAR therapeutics have the potential to treat and reverse disease in patients with all types and stages of systemic amyloidosis. Attralus was founded by scientific experts in the field of amyloidosis and the company is headquartered in Naples, FL.

Forward-Looking Statements
This press release contains forward-looking statements, including statements related to the efficacy, continued development, and potential of ¹²⁴I-evuzamitide and AT-05. Words such as “developing,” “potential,” “shown” and similar expressions are intended to identify forward-looking statements. These forward-looking statements are based upon Attralus’ current expectations. Forward-looking statements involve risks and uncertainties. Attralus’ actual results and the timing of events could differ materially from those anticipated in such forward-looking statements as a result of these risks and uncertainties. Attralus expressly disclaims any obligation or undertaking to release publicly any updates or revisions to any forward-looking statements contained herein to reflect any change in Attralus’ expectations with regard thereto or any change in events, conditions, or circumstances on which any such statements are based.

Contact:
Krishna Gorti, M.D. FRCS
Corporate Development
kgorti@attralus.com