RecruitingPhase 1

Actinium Therapy for Late-stage Aggressive Sarcomas

United States30 participantsStarted 2025-11-12

Plain-language summary

The goal of this clinical trial is to learn about the safety of drug \[Ac225\]RTX-2358 and the diagnostic imaging agent \[Cu64\]LNTH-1363S. Additionally Ratio Therapeutics will learn if \[Ac225\]RTX-2358 drug is effective in treating advanced sarcoma. The main questions the study aims to answer in Phase/Part 1 of the trial are: * Is \[Ac225\]RTX-2358 tolerable or does it cause toxicities (medical problems) in patients. * What is the most tolerable dose of \[Ac225\]RTX-2358 * Does the treatment show effectiveness on advanced sarcoma Participants will: * Take drug \[Ac225\]RTX-2358 once every 8 weeks (4 cycle target; 6 cycle maximum) over a period of 12 months * Visit the clinic three times for the first week of cycle one, then once a week for the remaining 7 weeks of cycle 1 for check-ups and tests. * For cycles 2-6: patient will visit the clinic once every 2 weeks for checkups and tests * Remain in long term follow-up for a period of four additional years

Who can participate

Age range18 Years

SexALL

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Inclusion criteria

✓. Histological confirmation of sarcoma at any point since diagnosis
✓. At least 1 prior treatment regimen
✓. Neutrophil count ≥ 1200 µL without granulocyte colony stimulating factor
✓. Platelet count ≥ 100,000 µL
✓. Hemoglobin ≥ 8 g/dL
✓. Total bilirubin level ≤ 1.5 × upper limit of normal (ULN).
✓. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤ 2.5 × ULN.
✓. Calculated creatinine clearance ≥ 60 mL/min. 6. Coagulation parameters (prothrombin time, international normalized ratio and activated partial thromboplastin time) ≤ 1.5 × ULN 7. All patients (males and females of childbearing potential) must agree to practice 2 forms of highly effective contraceptive precautions to prevent pregnancy from the time consent is signed and throughout the trial.

Exclusion criteria

✕. Palliative surgery or external beam radiation.

What they're measuring

Evaluate the safety (Frequency and severity of treatment emergent adverse events (TEAEs), Dose Limiting Toxicities (DLTs), serious adverse events (SAEs) and adverse events of special interest) of [Ac225-]RTX-2358

Timeframe: 48 weeks

Determine the MTD of the administered activity of [Ac-225]RTX-2358 and select the administered activity for use in the expansion cohort

Timeframe: 8 weeks

Trial details

NCT IDNCT07156565

SponsorRatio Therapeutics, Inc.

Sponsor typeINDUSTRY

Study typeINTERVENTIONAL

Primary completion2028-01

View on ClinicalTrials.gov More Advanced Soft Tissue Sarcoma trials