New targeted treatment for advanced prostate cancer using a radioactive compound

Targeted Radionuclide Therapy in Metastatic Prostate Cancer Using a New PSMA Ligand Radiolabelled With Terbium-161 (161Tb-SibuDAB) - Dose Identification/Escalation Phase Ia/b Study

Phase 1 Interventional University Hospital, Basel, Switzerland · NCT06343038

This study is testing a new radioactive treatment for advanced prostate cancer to see if it works better than current options and to find the best dose that helps patients with fewer side effects.

Quick facts

PhasePhase 1
Study typeInterventional
Enrollment25 (estimated)
Ages18 Years and up
SexAll
SponsorUniversity Hospital, Basel, Switzerland Academic / other
Drugs / interventionschemotherapy, radiation
Locations1 site (Basel)
Trial IDNCT06343038 on ClinicalTrials.gov

What this trial studies

This clinical trial investigates a novel treatment for metastatic castration-resistant prostate cancer (mCRPC) using a new PSMA ligand radiolabelled with terbium-161. The study is divided into two phases: the first compares the new treatment to an existing one at low doses, while the second aims to identify the optimal dose of the new treatment that maximizes benefits and minimizes side effects. The trial also evaluates various prostate cancer diagnostic methods to enhance treatment efficacy.

Who should consider this trial

Good fit: Ideal candidates are male patients over 18 with progressive PSMA-positive mCRPC who have undergone prior chemotherapy or are unfit for it.

Not a fit: Patients who do not have measurable PSMA-positive tumors or those with severe comorbidities may not benefit from this study.

Why it matters

Potential benefit: If successful, this treatment could provide a more effective option for patients with advanced prostate cancer who do not respond to current therapies.

How similar studies have performed: While there have been successful studies using PSMA-targeted therapies, this specific approach with terbium-161 is novel and has not been extensively tested.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Consent form signed
* Male patients with age \> 18 years
* Clinical indication for RLT with 177Lu-PSMA-I\&T (progressive PSMA-positive mCRPC patients after androgen receptor signalling pathway inhibitor and taxan-based chemotherapy or patient unfit for chemotherapy)
* Patients will be included in Phase Ia while being under active therapy with 177Lu-PSMA-I\&T (SoC) and after they have completed the first two cycles of 177Lu-PSMA-I\&T RLT
* At least 3 measurable tumours on PSMA PET/CT (\>1.5 cm) with sufficiently intense PSMA uptake (SUVmax\>20)
* ECOG Performance status: 0-1
* Blood parameters: a) Leucocytes ≥ 3 G/L; b) Haemoglobin ≥ 100 g/L; c) Thrombocytes ≥ 100 G/L
* Estimated glomerular filtration rate (eGFR) \> 45 ml/min
* Albumin \> 25 g/L
* ALT, AST, AP: ≤ 5 times upper standard value
* Bilirubin ≤ 2 times upper standard value
* For male patients who are not surgically sterilized (orchiectomy or vasectomy), appropriate contraceptive measures must be taken during RLT and until 4 months after completion of RLT. As acceptable contraceptive count sexual abstinence or double contraceptive methods: hormonal contraceptive (oral, transdermal, implants or injections) in combination with barrier methods (spiral, condom, diaphragm)

Exclusion Criteria:

* Prior PSMA-targeted RLT (except for the 2 first cycles in Part Ia)
* PSMA-negative (or PSMA-negative / FDG-positive) disease
* Known intolerance against DOTA, DOTAGA, urea-based analogues or against any of the components/formulation of 177Lu-PSMA-I\&T or 161Tb-SibuDAB solutions.
* Ongoing infection at the screening visit or a serious infection in the past 4 weeks
* Administration of another investigational product in the last 60 days before Visit 1 Day 1
* Prior or planed administration of a therapeutic radiopharmaceutical during 8 half-lives of the used radio-pharmaceutical's radionuclide, also during the ongoing study
* Any extensive radiotherapy involving bone marrow over the last 3 months before inclusion to the study
* Chemotherapy in the last 4 weeks before inclusion
* Any uncontrolled significant medical, psychiatric or surgical condition (active infection, unstable angina pectoris, cardiac arrhythmia, poorly controlled hypertension, poorly controlled diabetes mellitus \[HbA1c ≥ 9%\], uncontrolled congestive heart disease, etc.) or laboratory findings that might jeopardize the patient's safety or that would limit compliance with the objectives and assessments of the study. Any mental conditions which prevent the patient from understanding the type, extent and possible consequences of the study and/or an uncooperative attitude from the patient.
* Current history of any malignancy other than prostate cancer within 5 years of enrolment except for fully resected non-melanoma skin cancer

Where this trial is running

Basel

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Castration-resistant Prostate CancerRadioligand TherapyPhase Ia/IbCirculating Tumour CellsBiomarkers DevelopmentVoxel-based 3D Dosimetry
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.