Bayer Announces Positive Data for Investigational PET Radiotracer

May 7, 2026 — Bayer has announced positive topline results from the Phase III REVEAL study, an investigator-initiated study by Brigham and Women’s Hospital that evaluated the investigational PET radiotracer I 124 evuzamitide.^1,5 The study met the primary endpoints of sensitivity (the ability of a test to identify individuals who have the condition) and specificity (the ability of a test to identify individuals who do not have the condition) for the diagnosis of cardiac amyloidosis based on visual scan interpretation.¹ Bayer plans to present the complete results at an upcoming scientific congress.

I 124 evuzamitide is an investigational PET radiotracer — a radioactive diagnostic imaging agent injected into the body before a PET scan to assist with visualization–being studied in patients with suspected cardiac amyloidosis.⁵ I 124 evuzamitide is an investigational compound and has not been approved by any health authority for use in any country for any indication.

The compound was previously granted Breakthrough Therapy Designation for PET imaging in patients with suspected or known cardiac amyloidosis² as well as Orphan Drug status for both light-chain amyloidosis (AL) and transthyretin amyloidosis (ATTR) in the U.S. and the EU. ³ Bayer plans to discuss the data and submission for regulatory approval with the FDA and other health authorities. 

Data Results

“Cardiac amyloidosis is often under- or misdiagnosed,⁶ impacting patients’ ability to begin appropriate treatment earlier, when it may help prevent further organ damage,” said REVEAL principal investigator Dr. Sharmila Dorbala, Director of Nuclear Cardiology at Brigham and Women’s Hospital. “These I 124 evuzamitide data demonstrate the potential of a single test to help health care providers identify or exclude cardiac amyloidosis. Clinically, a sensitive, specific and quantitative PET tracer could help distinguish cardiac amyloidosis from other causes of heart failure, differentiate amyloid subtypes when used alongside appropriate laboratory testing, and track changes in cardiac amyloid burden over time.”

I 124 evuzamitide is one of two investigational amyloid radiotracers that Bayer acquired from Attralus, Inc. The compound is also known as AT-01. The acquisition, announced in early 2026, expanded Bayer’s radiology pipeline with complementary tracers targeting systemic amyloid disease and reinforced the company’s strategy to build a leading position in imaging for cardiovascular and other serious conditions.

“As a leader in radiology, we are committed to bringing forward options for earlier diagnosis of diseases such as cardiac amyloidosis for the benefit of patients,” said Dr. Konstanze Diefenbach, Head of Radiology Research & Development at Bayer’s Pharmaceuticals Division. “We are very excited about the positive topline results of the REVEAL study and are looking forward to sharing the data with the scientific community.”

Cardiac Amyloidosis 

Cardiac amyloidosis is a severe, progressive disease caused by the accumulation of misfolded proteins (amyloid) in heart tissue, making it stiff and thick which can impair its ability to pump blood effectively.⁷ As the disease is underdiagnosed, current estimates state the condition impacts approximately 400,000 patients worldwide,⁸ though the number is likely greater. Without appropriate diagnosis and treatment, cardiac amyloidosis can lead to heart failure, frequent hospitalizations and early mortality.⁷

Currently, there is no single, non-invasive test that can reliably detect and diagnose cardiac amyloidosis or quantify and monitor myocardial amyloid burden. Despite increasing disease awareness by health care providers, a prolonged diagnostic journey is common,⁶ with patients often consulting several specialists and receiving multiple imaging procedures before an accurate diagnosis.

The REVEAL Radiotracer Study⁵ 

The REVEAL (“Research with EVuzamitide I 124 to Elucidate Cardiac AmyLoidosis”) study is an investigator-initiated Phase III clinical trial of the investigational diagnostic imaging agent I 124 evuzamitide in patients with suspected cardiac amyloidosis with Brigham and Women’s Hospital in Boston, MA, as the study sponsor.

The main purpose of the study was to evaluate the efficacy and safety of the investigational radiotracer I 124 evuzamitide for diagnosing cardiac amyloidosis in participants with suspected cardiac amyloidosis compared to clinical standard of care (SoC) diagnosis. Secondary analyses assessed diagnostic performance in ATTR and AL subtypes. The imaging test used in this study was a positron emission tomography computed tomography (PET/CT) scan.

REVEAL is a multicenter, open-label, single-arm Phase III study conducted at 19 centers in the United States, evaluating 170 adults with suspected cardiac amyloidosis.

Participants received a single intravenous dose of I 124 evuzamitide, followed by cardiac and partial-body PET/CT imaging, 3-5 hours post-injection. All PET/CT images were independently read by experienced cardiac PET physicians, assessing visual presence or absence of cardiac tracer uptake, blinded to clinical data. SoC diagnosis was independently adjudicated by clinical amyloidosis experts, blinded to PET results, using routine diagnostic data collected up to 60 days after imaging.

Diagnostic sensitivity and specificity of I 124 evuzamitide were determined using SoC diagnosis as the reference standard.

References

1. Data on file.

2. Beighley, S. (2024, August 5). Attralus receives breakthrough therapy designation for its Pan-Amyloid Diagnostic Pet Imaging candidate 124i-evuzamitide (AT-01) for cardiac amyloidosis. Attralus. https://attralus.com/press-releases/attralus-receives-breakthrough-therapy-designation-for-its-pan-amyloid-diagnostic-pet-imaging-candidate-124i-evuzamitide-at-01-for-cardiac-amyloidosis

3. Beighley, S. (2022, December 19). Attralus receives FDA and Ema Orphan designation for AT-01 (iodine (I-124) evuzamitide), an investigational diagnostic for the management of Al and Attr Amyloidosis. Attralus. https://attralus.com/press-releases/attralus-receives-fda-and-ema-orphan-designation-for-at-01-iodine-i-124-evuzamitide-an-investigational-diagnostic-for-the-management-of-al-and-attr-amyloidosis

4. Rozenbaum, M. H., Large, S., Bhambri, R., Stewart, M., Whelan, J., van Doornewaard, A., Dasgupta, N., Masri, A., & Nativi-Nicolau, J. (2021). Impact of Delayed Diagnosis and Misdiagnosis for Patients with Transthyretin Amyloid Cardiomyopathy (ATTR-CM): A Targeted Literature Review. Cardiology and Therapy, 10(1), 141-159. https://doi.org/10.1007/s40119-021-00219-5.

5. Research With I-124 EVuzamitide to Elucidate Cardiac AmyLoidosis (REVEAL). Clinicaltrials.gov. (n.d.). https://clinicaltrials.gov/study/NCT06788535

6. Dang D, Fournier P, Cariou E, Huart A, Ribes D, Cintas P, Roussel M, Colombat M, Lavie-Badie Y, Carrié D, Galinier M, Lairez O. Gateway and journey of patients with cardiac amyloidosis. ESC Heart Fail. 2020 Oct;7(5):2418-2430. doi: 10.1002/ehf2.12793. Epub 2020 Jun 26. PMID: 32588554; PMCID: PMC7524246.

7. Cardiac amyloidosis: What you need to know. Cleveland Clinic. (2025, October 13). https://my.clevelandclinic.org/health/diseases/22598-cardiac-amyloidosis

8. ClinicalTrials.gov. Efficacy and Safety of AG10 in Subjects With Transthyretin Amyloid Cardiomyopathy (ATTRibute-CM). Available at: https://clinicaltrials.gov/study/NCT03860935. [Accessed April 2026]