Bayer Reports Positive Phase III Results for I-124 Evuzamitide in Cardiac Amyloidosis

REVEAL Study Meets Primary Diagnostic Endpoints

Bayer has announced the first detailed results from the Phase III REVEAL study evaluating iodine-124 evuzamitide, also known as I-124 evuzamitide or AT-01, as an investigational PET radiotracer for diagnosing cardiac amyloidosis.

The study met its primary endpoints for sensitivity and specificity based on visual interpretation of PET scans. The results also met predefined success criteria for detecting two major types of cardiac amyloidosis: light-chain amyloidosis (AL) and transthyretin amyloidosis (ATTR).

The REVEAL study was an investigator-initiated clinical trial sponsored by Brigham and Women’s Hospital in Boston. It included 170 adults with suspected cardiac amyloidosis across 18 centers in the United States.

The results were presented on August 30, 2026, during a late-breaking oral presentation at the European Society of Cardiology Congress 2026 in Munich, Germany. The findings were also published simultaneously in The Journal of the American Medical Association.

I-124 evuzamitide remains investigational and has not been approved by any health authority in any country for any indication.

Why Diagnosing Cardiac Amyloidosis Can Be Difficult

Cardiac amyloidosis is a serious and progressive disease in which abnormal proteins called amyloid build up in the heart.

As these proteins accumulate, the heart muscle can become thicker and stiffer. This can make it harder for the heart to pump blood properly and may eventually lead to heart failure.

Getting the right diagnosis can take time. Patients may see several specialists and undergo multiple tests before doctors can determine what is causing their symptoms.

Dr. Sharmila Dorbala, principal investigator of the REVEAL study and director of nuclear cardiology at Brigham and Women’s Hospital, said that these challenges can result in delayed diagnosis, underdiagnosis or misdiagnosis.

This makes better diagnostic tools important, particularly tools that can help doctors identify cardiac amyloidosis without relying only on invasive procedures or a long series of tests.

I-124 Evuzamitide Shows High Diagnostic Sensitivity

The Phase III REVEAL study evaluated whether I-124 evuzamitide could accurately identify patients with cardiac amyloidosis using PET imaging.

Three independent readers reviewed the PET scans without access to the patients’ clinical information.

The study showed strong sensitivity across all three readers.

Reader 1 reported a sensitivity of 94%, with a 95% confidence interval of 85% to 98%.

Reader 2 also reported a sensitivity of 94%, with a 95% confidence interval of 85% to 98%.

Reader 3 reported a sensitivity of 90%, with a 95% confidence interval of 81% to 95%.

When the majority read was used, meaning at least two of the three readers agreed on the scan interpretation, sensitivity was 94%, with a 95% confidence interval of 85% to 98%.

Sensitivity is important because it shows how well a diagnostic test can identify people who actually have the disease.

Specificity Results Also Meet the Study Target

The study also assessed specificity, which measures how well a test can correctly identify people who do not have the disease.

Reader 1 reported specificity of 84%, with a 95% confidence interval of 75% to 91%.

Reader 2 reported specificity of 85%, with a 95% confidence interval of 76% to 92%.

Reader 3 reported specificity of 89%, with a 95% confidence interval of 81% to 95%.

Using the majority read, specificity was 86%, with a 95% confidence interval of 77% to 92%.

Together, the sensitivity and specificity results allowed the study to meet its primary efficacy endpoints.

Results Across AL and ATTR Amyloidosis

Cardiac amyloidosis is not one single disease. Two major types are AL amyloidosis and ATTR amyloidosis.

AL amyloidosis is caused by abnormal light-chain proteins produced by plasma cells. ATTR amyloidosis is linked to transthyretin, a protein that can become unstable and form amyloid deposits.

The REVEAL study looked at how I-124 evuzamitide performed in both types.

For ATTR amyloidosis, the majority read showed sensitivity of 96%, with a 95% confidence interval of 87% to 100%. Specificity was 86%, with a 95% confidence interval of 77% to 92%.

For AL amyloidosis, sensitivity based on the majority read was 95%, with a 95% confidence interval of 76% to 100%. Specificity was again 86%, with a 95% confidence interval of 77% to 92%.

These secondary endpoints also met the predefined success criteria for the overall study population.

Safety Findings From the Phase III Study

The study also evaluated the safety of I-124 evuzamitide.

Among the 170 participants who received the investigational radiotracer, 55 people, or 32.4%, experienced at least one treatment-emergent adverse event between Day 1 and Day 30.

Eleven participants, or 6.5%, experienced a serious treatment-emergent adverse event. However, these serious events were considered unrelated to I-124 evuzamitide.

Only one treatment-emergent adverse event, fatigue, was considered related to the investigational radiotracer.

The most frequently reported adverse events affecting more than 1% of participants included upper respiratory tract infection, dizziness, nausea, vomiting, syncope, hyperglycemia and skin laceration.

There were no deaths during the study period. There were also no I-124 evuzamitide-related adverse events that resulted in treatment discontinuation.

How I-124 Evuzamitide Works With PET Imaging

I-124 evuzamitide is an investigational radioactive diagnostic imaging agent.

Patients receive the radiotracer through an intravenous injection before undergoing PET imaging. The compound is designed to help doctors visualize amyloid deposits in the body.

In the REVEAL study, participants received a single intravenous dose of I-124 evuzamitide. Cardiac and partial-body PET/CT imaging was then performed three to five hours after injection.

The scans were independently reviewed by experienced cardiac PET physicians. The readers assessed whether cardiac tracer uptake was present or absent while remaining blinded to the patients’ clinical information.

An independent clinical adjudication committee then reviewed the available diagnostic information without knowing the PET results.

The committee established the study's standard of truth using diagnostic information collected up to 60 days after imaging.

Bayer Expands Its Molecular Imaging Pipeline

I-124 evuzamitide is one of two investigational amyloid radiotracers that Bayer acquired from Attralus, Inc.

The acquisition was intended to expand Bayer's radiology pipeline with imaging agents designed to target systemic amyloid disease.

The company sees molecular imaging as an area that could help physicians better understand disease activity by allowing biological processes to be visualized in the body.

I-124 evuzamitide has previously received Breakthrough Therapy Designation from the U.S. Food and Drug Administration for PET imaging in patients with suspected or known cardiac amyloidosis.

It has also received Orphan Drug status for AL and ATTR amyloidosis in both the United States and the European Union.

These designations do not mean that the product has been approved. I-124 evuzamitide remains under clinical investigation.

Bayer Plans Regulatory Discussions

Following the Phase III results, Bayer plans to discuss the data and potential regulatory submissions with the FDA and other health authorities.

The company will need to complete the appropriate regulatory process before I-124 evuzamitide could potentially become available for clinical use.

The positive Phase III findings provide Bayer with additional clinical evidence as it evaluates the next steps for the investigational diagnostic agent.

Why Better Imaging Could Matter for Patients

Today, diagnosing cardiac amyloidosis can involve a long clinical journey.

Doctors may need to combine medical history, laboratory testing, imaging and other diagnostic information to determine whether a patient has the disease and which type of amyloidosis is involved.

There is currently no single non-invasive test that can reliably detect and diagnose cardiac amyloidosis while also measuring and monitoring the amount of amyloid in the heart.

This is where molecular imaging could play an important role.

PET imaging can provide doctors with a way to see biological activity inside the body. For diseases such as cardiac amyloidosis, this could potentially help improve disease detection and support more informed treatment decisions.

The REVEAL results add to the research exploring whether amyloid-targeting radiotracers can become useful tools in this setting.

Bayer Continues Investment in Diagnostic Imaging

Bayer has a long history in diagnostic imaging and offers products used across several imaging technologies, including CT, X-ray, MRI and PET.

Its radiology business also includes medical devices and informatics solutions designed to support diagnostic imaging workflows.

In 2025, Bayer's radiology products generated €2.2 billion in sales.

The company continues to invest in molecular imaging and other areas that could expand the role of diagnostic imaging in healthcare.

About the REVEAL Study

The REVEAL study stands for “Research with EVuzamitide I 124 to Elucidate Cardiac AmyLoidosis.”

It was a multicenter, open-label, single-arm Phase III study conducted at 18 centers in the United States.

The trial enrolled 170 adults with suspected cardiac amyloidosis.

Participants received one intravenous dose of I-124 evuzamitide before undergoing PET/CT imaging. The main objective was to assess the sensitivity and specificity of the radiotracer for diagnosing cardiac amyloidosis compared with a clinical standard of truth.

Secondary analyses evaluated performance in patients with ATTR and AL amyloidosis.

Brigham and Women’s Hospital in Boston served as the study sponsor, while the research was conducted as an investigator-initiated clinical trial.

Bayer's Focus on the Future of Molecular Imaging

The latest REVEAL data give Bayer additional clinical evidence for I-124 evuzamitide as it considers the regulatory path for the investigational PET radiotracer.

The company says the findings reflect its continued focus on advancing diagnostic imaging research for people affected by serious diseases.

For patients with suspected cardiac amyloidosis, a diagnostic approach that can provide clearer information through molecular imaging could become an important area of future research as the clinical development of I-124 evuzamitide continues.