A Study to Evaluate Organ Level Uptake Repeatability of 1... | NCT05235269

NCT05235269

Protocol Section

Identification Module

Results Section

Participant Flow Module

Annotation Section

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Document Section

Large Document Module

Derived Section

Miscellaneous Info Module

Status Module

Label	Type	Description	Intervention Names
Single arm	Other	124I-AT-01	Drug: 124I-AT-01

Name	Type	Description	Arm Group Labels	Other Names
124I-AT-01	Drug	All participants received 1 mCi 124I-AT-01 on Day 1 and at Week 6 via IV infusion over 2-5 minutes or slow IV bolus at 1 mL/5 seconds.	Single arm

Outcomes Module

Primary Outcomes

Measure	Description	Time Frame
Within-Participant Coefficient of Variation [wCV] Associated With the Quantification (SUVmax) of Radioactivity Associated With Organ-Level Radiotracer Uptake	Between-visit repeatability of organ-specific (heart, kidney, liver, spleen) quantitation (SUVmax) of radiotracer uptake following PET/CT imaging of 124I-AT-01 in participants with AL or ATTR systemic amyloidosis was assessed. wCV with its associated 95% RC provides guidance on the level of change in organ-specific quantitation of radiotracer uptake that needs to be observed to be confident that a true change in uptake has occurred. Smaller values of wCV represent better agreement. Computation of wCV and associated RCs in addition to the two-sided 95% CI is described in the SAP. Only images from participants/organs with positive uptake were included. RCs between visits were calculated using the difference of the log of the average of the 2 reads for a reader at Day 1 and the log of the average of the 2 reads for the same reader at Week 6. The 95% RCs were calculated on the log-transformed data and exponentiated to determine the limits in percentages.	Day 1 and Week 6
Within-Participant Coefficient of Variation [wCV] Associated With the Quantification (SUVpeak) of Radioactivity Associated With Organ-Level Radiotracer Uptake	Between-visit repeatability of organ-specific (heart, kidney, liver, spleen) quantification (SUVpeak) of radiotracer uptake following PET/CT imaging of 124I-AT-01 in participants with AL or ATTR systemic amyloidosis was assessed. wCV with its associated 95% RC provides guidance on the level of change in organ-specific quantitation of radiotracer uptake that needs to be observed to be confident that a true change in uptake has occurred. Computation of wCV and associated RCs in addition to the two-sided 95% CI is described in the SAP. Only images from participants/organs with positive uptake were included. RCs between visits were calculated using the difference of the log of the average of the 2 reads for a reader at Day 1 and the log of the average of the 2 reads for the same reader at Week 6. The 95% RCs were calculated on the log-transformed data and exponentiated to determine the limits in percentages.	Day 1 and Week 6
Intraclass Correlation Coefficient (ICC) Associated With the Quantification (SUVmax) of Radioactivity Associated With Organ-Level Radiotracer Uptake

Secondary Outcomes

Measure	Description	Time Frame
Number of Participants With At Least 1 Treatment-Emergent Adverse Event (TEAE)	TEAEs were defined as events that were newly reported or reported to worsen in severity after the start of treatment. Adverse events (AEs) that occurred after the treatment start date, occurred on the treatment start date with a time that was equal to or after treatment start time, or that had a missing AE start date were categorized as treatment emergent.

Eligibility Module

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 <1% per year during the treatment period and for at least 90 days after the last dose of 124I-AT-01.
1. A woman is considered of childbearing potential if she is postmenarchal, has not reached a postmenopausal state, and has not undergone surgical sterilization.
2. Examples of contraceptive methods with a failure rate of <1% per year include bilateral tubal ligation, male sterilization, established, proper use of hormonal contraceptives that inhibit ovulation, hormone-releasing intrauterine devices, and copper intrauterine devices.
3. Contraception methods that do not result in a failure rate of <1% per year such as cap, diaphragm, or sponge with spermicide, or male or female condom with or without spermicide, are not acceptable.
4. The reliability of sexual abstinence should be evaluated in relation to the duration of the clinical trial and the preferred and usual lifestyle of the subject.
For men: agreement to remain abstinent or use contraceptive measures and agreement to refrain from donating sperm, as defined below:

a) With female partners of childbearing potential, men must remain abstinent or use a condom plus an additional contraceptive method that together result in a failure rate of <1% per year during the treatment period and for at least 120 days (a spermatogenesis cycle) after the last dose of study intervention. Men must refrain from donating sperm during this same time period.
Able to undergo two PET/CT scans as part of the study, including ability to lie supine for up to 1 hour.
Has a history of AL or ATTR systemic amyloidosis with at least one organ with clinically demonstrable amyloid involvement defined by:
1. AL systemic amyloidosis: Positive tissue biopsy for AL amyloid, and achieved a hematologic very good partial response or complete response based on their most recent assessment, and at least one of the following: 1) Organ biopsy positive for amyloid, or 2) Natriuretic peptide (NT-proBNP) >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
2. 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.

Name	Affiliation	Role
Gregory M. Bell, MD	Attralus, Inc.	Study Director

Facility	Status	City	State	ZIP	Country	Contacts
PET/CT Imaging of Berkeley		Berkeley	California	94705	United States
Northern California PET Imaging Center

ID	Title	Description
FG000	124I-AT-01	All participants received 1 mCi 124I-AT-01 on Day 1 and at Week 6 via IV infusion over 2-5 minutes or slow IV bolus at 1 mL/5 seconds.

ID	Title	Description
BG000	124I-AT-01	All participants received 1 mCi 124I-AT-01 on Day 1 and at Week 6 via IV infusion over 2-5 minutes or slow IV bolus at 1 mL/5 seconds.

Units	Counts
Participants	BG000

Title	Description	Population Description	Parameter Type	Dispersion Type	Unit of Measure	Calculate Percentage	Denominator Units Selected	Denominators	Classes
Age, Continuous			Mean

Outcome Measures Module

Outcome Measures

Type	Title	Description	Population Description	Reporting Status	Anticipated Posting Date	Parameter Type	Dispersion Type	Unit of Measure	Calculate Percentage	Time Frame	Units Analyzed	Denominator Units Selected	Arm/Group Information	Denominators	Classes	Analyses
Primary	Within-Participant Coefficient of Variation [wCV] Associated With the Quantification (SUVmax) of Radioactivity Associated With Organ-Level Radiotracer Uptake	Between-visit repeatability of organ-specific (heart, kidney, liver, spleen) quantitation (SUVmax) of radiotracer uptake following PET/CT imaging of 124I-AT-01 in participants with AL or ATTR systemic amyloidosis was assessed. wCV with its associated 95% RC provides guidance on the level of change in organ-specific quantitation of radiotracer uptake that needs to be observed to be confident that a true change in uptake has occurred. Smaller values of wCV represent better agreement. Computation of wCV and associated RCs in addition to the two-sided 95% CI is described in the SAP. Only images from participants/organs with positive uptake were included. RCs between visits were calculated using the difference of the log of the average of the 2 reads for a reader at Day 1 and the log of the average of the 2 reads for the same reader at Week 6. The 95% RCs were calculated on the log-transformed data and exponentiated to determine the limits in percentages.	The Image Evaluable Set was defined as all participants who underwent PET/CT scans on both Day 1 and 6 to 8 weeks after Day 1 and who had evaluable images at both time points.	Posted		Number	95% Confidence Interval	coefficient of variation		Day 1 and Week 6

Adverse Events Module

Arm/Groups

ID	Title	Description	Deaths (Affected)	Deaths (At Risk)	Serious Events (Affected)	Serious Events (At Risk)	Other Events (Affected)	Other Events (At Risk)
EG000	124I-AT-01	All participants received 1 mCi 124I-AT-01 on Day 1 and at Week 6 via IV infusion over 2-5 minutes or slow IV bolus at 1 mL/5 seconds.

Type	Includes Protocol	Includes SAP	Includes ICF	Document Label	Document Date	Document Uploaded Date	Document File Name
Prot	Yes	No	No	Study Protocol	Mar 8, 2022	Jul 29, 2025	Prot_000.pdf
SAP	No	Yes	No	Statistical Analysis Plan	Dec 16, 2022	Jul 31, 2025	SAP_001.pdf

ID	Term
D057165	Proteostasis Deficiencies
D008659	Metabolic Diseases
D009750	Nutritional and Metabolic Diseases