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DTC - Differentiated Thyroid CancerPhase 1NCT07287748

A Phase I Trial of Af-001 in Patients With Differentiated Thyroid Cancer

A Phase 1 study testing [211At]NaAt in people with DTC - Differentiated Thyroid Cancer, run by Alpha Fusion Inc. at 1 site in Japan.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial summary

This trial consists of 2 parts, i.e., Part Ia and Ib. The Part Ia is to evaluate the safety and tolerability of a single intravenous dose of af-001 in patients with radically unresectable, recurrent, metastatic differentiated thyroid cancer (papillary carcinoma, follicular carcinoma) refractory to or intolerant of… Read more about this study

Who is it for?
Ages 18 years and older
Conditions the study is for
DTC - Differentiated Thyroid Cancer
What is being tested?
[211At]NaAt
Could I receive a placebo?
No, everyone receives an active treatment
How many people
38 participants
Where
1 siteJapan
Study dates
1 Jan 2026to 31 Jul 2028
Phase
Phase 1
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • <Ia part>
  • Patients with differentiated thyroid cancer (papillary carcinoma, follicular carcinoma) after total thyroidectomy.
  • Patients with radically unresectable, recurrent, metastatic disease who are judged by the principal investigator or sub-investigator (hereinafter, "principal/sub-investigators") to be refractory to or intolerant of standard-of-care therapy.
  • <Ib part>
  • Patients with radically unresectable, recurrent, metastatic disease who are RAI naive
  • Patients with measurable lesions. <Ia/Ib part>
  • Patients with an Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0 to 2 and stable general condition.
  • Patients expected to survive for at least 6 additional months based on clinical symptoms and physical examination findings.

Who cannot join

  • <Ia/Ib part>
  • Patients who need to preserve fertility.
  • Females who are pregnant or may be pregnant, breastfeeding patients, or patients or their partners who cannot agree to appropriate contraception.
  • Patients with active multiple cancers (synchronous multiple cancers and ectopic double cancers with a disease-free period of <=3 years).
  • Patients with uncontrolled active infections.
  • Patients who are positive for hepatitis B virus surface (HBs) antigen, hepatitis C virus (HCV) antibodies, or human immunodeficiency virus (HIV) antibodies.

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

Alpha Fusion Clinical Development contact

+81335185330

development@alpha-fusion.com

Japan1 site, 1 recruiting

  • National Cancer Center Hospital East

    Kashiwa

    Recruiting

Other trials in Japan

About this study

Official title: A Phase I Trial of the Alpha Particle-emitting Radiopharmaceutical, Af-001, in Patients With Differentiated Thyroid Cancer

This trial consists of 2 parts, i.e., Part Ia and Ib. The Part Ia is to evaluate the safety and tolerability of a single intravenous dose of af-001 in patients with radically unresectable, recurrent, metastatic differentiated thyroid cancer (papillary carcinoma, follicular carcinoma) refractory to or intolerant of standard-of-care therapy, who have received total thyroidectomy, and to determine the MTD (Maximum tolerated dose).

Part Ib is to evaluate the efficacy and safety of af-001 mutiple doses to patients with radically unresectable, recurrent, metastatic differentiated thyroid cancer (papillary carcinoma, follicular carcinoma), who have received total thyroidectomy and are RAI naïve, randomized into two arms at the determined MTD or the MTD-1 dose level, and to determine the recommended Phase II dose (RP2D)

Read the detailed description

The Part Ia is a dose escalation part. The Part Ib is a parallel-group comparative study part based on the MTD determined in Part Ia, in which 10 patients each will be randomly assigned to one of two treatment arms, at the MTD for af-001 or the MTD-1 dose level. Patients will be randomly assigned by the enrollment system (allocated at a ratio of 1:1). Random assignment will be performed using the stratified permuted block method. The stratification factor will be the site(s) of metastases.

Being tested
[211At]NaAt
Keywords
DTC, At211, alpha particle-emitting radiopharmaceutical

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • [211At]NaAtDrug

    MTD or MTD-1 level to be tested

Study groups in NCT07287748
Study groupRoleWhat they receive
[211At]NaAtExperimentalPh1a: single dose, Ph1b: mutiple dose
Receives: Drug: [211At]NaAt

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Ph1a: DLT (Dose-limiting toxicity ) based on Japanese translation of the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0, Japan Clinical Oncology Group (JCOG) version

    DLT evaluation criteria:

    1. Grade ≥4* hematologic toxicity that persists for at least 7 days
    2. Febrile neutropenia regardless of duration
    3. Grade ≥3* thrombocytopenia associated with a bleeding tendency or that requires platelet transfusions
    4. Anemia that requires red blood cell transfusions
    5. Neutropenia associated with infection
    6. Grade ≥3* non-hematologic toxicity that persists for at least 7 days and does not improve with symptomatic treatment, with the following exceptions:
    • Toxicities that can be controlled to Grade ≤2* with maximum supportive herapy
    • Those due to the progression of the primary tumor

    [*: Grades as defined in CTCAE v.5.0 (Japanese translation) JCOG version]

    Measured: 4 weeks

  2. Ph1b: Assessment of tumor reduction effect on MRI or CT scan images

    Using the "Revised version of the Response Evaluation Criteria in Solid Tumors (RECIST) guidelines version 1.1 (Japanese translation of JCOG version 1.0)" as a reference.

    Measured: 24 weeks

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted17 Dec 2025
  2. Study start1 Jan 2026 (estimated)
  3. Primary completion31 Jul 2028 (estimated)
  4. Study completion31 Jul 2028 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 1
Primary purpose
Treatment
Allocation
Not applicable
Intervention model
Single group
Model description
Phase 1a, Phase 1b
Masking
None (open label)
Enrolment
38 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07287748
Sponsor's protocol ID
af-001TH
Other IDs
jRCT2031250472
Status last verified
Dec 2025
First submitted
20 Nov 2025
Last updated
31 Dec 2025
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

A Phase 1 study testing [211At]NaAt in people with DTC - Differentiated Thyroid Cancer, run by Alpha Fusion Inc. at 1 site in Japan.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 8 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: looking for participants now, as of the sponsor's last update on 31 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Japan. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Alpha Fusion Clinical Development (+81335185330, development@alpha-fusion.com), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Ph1a: DLT (Dose-limiting toxicity ) based on Japanese translation of the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0, Japan Clinical Oncology Group (JCOG) version (time frame: 4 weeks). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07287748.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 31 Dec 2025.

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