A Prospective, Open-label, Single-arm, Exploratory Clinical Trial to Evaluate the Safety and Tolerability of 225Ac-TR2205 Injection in Patients With Triple-negative Breast Cancer.

NCT07340424 | Recruiting Early Phase 1

• 1 other identifier: TR2205-305
• Study Type: interventional
• Target: 15
• Locations: 1 country
• Sites: 1

Brief Summary

This study is a prospective, single-center, single-arm, open-label research. It evaluates the safety and tolerability of 225Ac-TR2205 in patients with triple-negative breast cancer (TNBC), and assesses its radiation dosimetry and initial efficacy.

Conditions

Advanced Metastatic Triple-negative Breast Cancer (mTNBC)

Outcome Measures

Primary Outcomes (1)

• The incidence and severity grades of adverse events (AE), serious adverse events (SAE), and unexpected serious adverse reactions (SUSAR) were evaluated according to the CTCAE 5.0 standard.

  8 weeks after the last dose

Study Arms (1)

225Ac-TR2205 Injection

EXPERIMENTAL

Drug: 225Ac-TR2205 Injection

Interventions

225Ac-TR2205 Injection DRUG

Patients will receive 225Ac-TR2205 injection administration at an interval of 8 weeks between each dose.

225Ac-TR2205 Injection

Eligibility Criteria

• Age: 18 Years+
• Sex: female
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Voluntary participation in the study and signing of the informed consent form.
• Female patients aged 18 years and above.
• Patients with triple-negative breast cancer who have been diagnosed by histopathology \[immune histochemistry estrogen receptor (ER) positive rate \< 1% is defined as ER negative expression; progesterone receptor (PR) positive rate \< 1% is defined as PR negative; human epidermal growth factor receptor 2 (HER2) expression 0-1+ or HER2 ++ but fluorescence in situ hybridization/colorimetric in situ hybridization (FISH/CISH) negative is defined as HER2 negative expression\].
• Patients with metastatic triple-negative breast cancer who have received at least 2 systemic treatments (at least 1 of which is for metastatic disease).
• Patients with at least 1 measurable lesion (tumor evaluation according to RECIST 1.1).
• ECOG performance status assessment of 0-1.
• Clinical significance of hematological toxicity related to previous treatment must recover to ≤ 2 grade, and non-hematological toxicity ≤ 1 grade (except for hair loss).
• For patients with reproductive potential: 7 days before the first administration, fertile women must confirm that the urine pregnancy test is negative and agree to use effective contraceptive measures during the use of the study drug and within 6 months after the last administration (such as oral contraceptives, intrauterine devices, restraint of sexual desire or barrier contraception combined with spermicides, etc.).

You may not qualify if:

• Patients who received radiotherapy (except palliative radiotherapy) or chemotherapy, immunotherapy within 3 weeks before treatment, except for bisphosphonates (which can be used for bone metastasis), are excluded.
• Patients who received radionuclide therapy within 6 months before enrollment, such as strontium-89, samarium-153, rhenium-186, rhenium-188, radium-223, lutetium-177, actinium-225, or whole-body radiotherapy.
• Patients who are undergoing chemotherapy, immunotherapy, biological therapy, off-label radionuclide therapy, or other investigational treatments.
• Patients who have undergone major surgery within 28 days before enrollment.
• Patients evaluated by the investigator are expected to have a life expectancy of less than 3 months.
• Bone scans show super bone imaging, defined as uniform and significant concentration of radioactive isotopes in the entire skeleton relative to soft tissue, while the urinary system is not visible or shows mild visibility.
• Symptomatic spinal cord compression, or clinical or imaging evidence suggesting impending spinal cord compression.
• Patients with uncontrollable central nervous system (CNS) metastases, who need symptomatic treatment with glucocorticoids or mannitol, and if necessary, enhanced CT or MRI to clarify the status of brain metastases.
• Patients with a history of other malignant tumors, except for those with fully treated malignant tumors that have survived without treatment for more than 3 years without recurrence or progression, or patients with fully treated non-melanoma skin cancer and superficial bladder cancer.
• Patients with a history that may interfere with the purpose of the study and assessment, or the investigator determines that the patient has any condition that cannot cooperate with imaging examinations, treatment, and procedures.

Sponsors & Collaborators

• Xiaorong Sun: lead

Study Sites (1)

Cancer Hospital of Shandong First Medical University

Jinan, Shandong, China

RECRUITING

Central Study Contacts

Xiaorong Sun

CONTACT

0531-67626287; xrsun@sdfmu.edu.cn

Study Design

• Study Type: interventional
• Phase: early phase 1
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Director of Nuclear Medicine Department

Study Record Dates

• First Submitted: January 6, 2026
• First Posted: January 14, 2026
• Study Start: May 22, 2025
• Primary Completion (Estimated): April 1, 2027
• Study Completion (Estimated): May 1, 2029
• Last Updated: January 14, 2026

Record last verified: 2026-01

Locations

CN (1)