Phase 2
N=33
A Study to Evaluate Organ Level Uptake Repeatability of 124I AT-01 in Subjects With Systemic Amyloidosis
Amyloidosis
Bottom Line
View on ClinicalTrials.gov: NCT05235269 ↗Enrolled (actual)
33
Serious AEs
3.0%
Results posted
Sep 2025
Primary outcome: Primary: Within-Participant Coefficient of Variation [wCV] Associated With the Quantification (SUVmax) of Radioactivity Associated With Organ-Level Radiotracer Uptake — 14.58; 14.50; 12.97; 16.28 coefficient of variation
Study Design & Population
- Study type
- Interventional
- Phase
- Phase 2
- Interventions
- 124I-AT-01 (Drug)
- Age
- Adult, Older Adult · 18+ yrs
- Sex
- All
- Sponsor
- Attralus, Inc.
- Primary completion
- Feb 2023
Outcome Measures
| Outcome | Result | p-value |
|---|---|---|
| PRIMARY Within-Participant Coefficient of Variation [wCV] Associated With the Quantification (SUVmax) of Radioactivity Associated With Organ-Level Radiotracer Uptake |
14.58; 14.50; 12.97; 16.28; 9.46; 15.18 | — |
| PRIMARY Within-Participant Coefficient of Variation [wCV] Associated With the Quantification (SUVpeak) of Radioactivity Associated With Organ-Level Radiotracer Uptake |
13.06; 11.57; 8.21; 12.82; 9.95; 13.88 | — |
| PRIMARY Intraclass Correlation Coefficient (ICC) Associated With the Quantification (SUVmax) of Radioactivity Associated With Organ-Level Radiotracer Uptake |
0.903; 0.955; 0.973; 0.964; 0.971; 0.975 | — |
| PRIMARY Intraclass Correlation Coefficient (ICC) Associated With the Quantification (SUVpeak) of Radioactivity Associated With Organ-Level Radiotracer Uptake |
0.960; 0.987; 0.994; 0.991; 0.993; 0.990 | — |
| SECONDARY Number of Participants With At Least 1 Treatment-Emergent Adverse Event (TEAE) |
13 | — |
| SECONDARY Clinical Laboratory Values - Chemistry (mmol/L) |
-0.028; -0.035; -0.7; -1.0; -0.9; 0.4 | — |
| SECONDARY Clinical Laboratory Values - Chemistry (Umol/L) |
1.0136; 1.2315; 5.24; 1.77 | — |
| SECONDARY Clinical Laboratory Values - Chemistry (g/L) |
-0.4; -1.5; -0.7; -1.7 | — |
| SECONDARY Clinical Laboratory Values - Chemistry (IU/L) |
-1.4; -2.6; -2.9; -3.1; -0.3; -1.8 | — |
| SECONDARY Clinical Laboratory Values - Hematology (% of White Blood Cell [WBC] Count) |
-0.1; -0.1; -0.2; -0.1; 0.0; 1.1 | — |
| SECONDARY Clinical Laboratory Values - Hematology (10^9 Cells/L) |
-0.02; -0.03; -0.02; -0.01; -0.27; -0.29 | — |
| SECONDARY Clinical Laboratory Values - Hematology (10^12 Cells/L) |
0.000; -0.055 | — |
| SECONDARY Clinical Laboratory Values - Hematology (g/L) |
-0.4; -2.1 | — |
| SECONDARY Clinical Laboratory Values - Hematology (% of Total Blood Cell Count) |
-0.19; -0.54 | — |
| SECONDARY Change From Baseline in Vital Signs - Blood Pressure (mmHg) |
-2.8; -3.9; -8.5; -3.2; 0.2; -2.2 | — |
| SECONDARY Change From Baseline in Vital Signs - Heart Rate (Beats/Min) |
1.1; 0.9; 1.0 | — |
| SECONDARY Change From Baseline in Anti-Drug Antibodies (ADA) |
26; 0 | — |
Summary
This study is designed to assess the repeatability of organ-specific quantitation of radiotracer uptake following Positron Emission Tomography/Computed Tomography (PET/CT) imaging of AT- 01 in subjects with amyloid light chain (AL) or amyloid transthyretin (ATTR) systemic amyloidosis.
Eligibility Criteria
Inclusion Criteria
- Understands the study procedures and is capable of giving signed informed consent, as described in Appendix 1, which includes compliance with the requirements and restrictions listed in the informed consent form (ICF) and in this protocol.
- Male or female ≥18 years of age.
- For women of childbearing potential: agreement to remain abstinent or use contraceptive methods that result in a failure rate of 650 pg/mL, or 3) left ventricle septal wall thickness >12 mm by echocardiogram or cardiac magnetic resonance (CMR), or 4) 24-hour urine protein >500 mg, or 5) Urine albumin-to-creatinine ratio >300 mg/g
- ATTR (wild type or variant) systemic amyloidosis: Positive cardiac biopsy for ATTR amyloid, or at least two of the following: 1) Positive extracardiac tissue biopsy for ATTR amyloid or positive transthyretin gene mutation associated with amyloid, or 2) left ventricle septal wall thickness >12 mm by echocardiogram or CMR, or 3) pyrophosphate (PYP) scintigraphy with myocardial uptake ≥grade 2.
Exclusion Criteria
- Is pregnant or breast-feeding.
- Is mentally or legally incapacitated, has significant emotional problems at the time of the study, or has a history of psychosis.
- Has received in the last 6 months or are currently receiving treatment with anti-amyloid monoclonal antibody therapy or are expected to begin treatment prior to completing this study.
- Has received heparin or heparin analogs within 7 days of Day 1.
- Has a significant co-morbidity (e.g., Easter Cooperative Oncology Group (ECOG) score of 3 or greater), New York Heart Association (NYHA) Class IV heart failure, uncontrolled infection, or other ongoing serious illness.
- Has active thyroid disease.
- Has a known allergy to potassium iodine treatment.
- Is receiving hemodialysis or peritoneal dialysis.
- Has severe claustrophobia that would prevent completion of the PET/CT imaging protocol.
- Has received an investigational agent within five half-lives of the agent or 30 days, whichever is longer, prior to Screening.
- Has any illness that, in the opinion of the Investigator, might confound the results of the study or pose additional risk to the subject.
Data sourced from ClinicalTrials.gov (NCT05235269). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication.