protocolSection identificationModule nctId: NCT06343038, orgStudyIdInfo id: 2023-01868; th23Nicolas, briefTitle: 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, acronym: PROGNOSTICS, statusModule overallStatus: NOT_YET_RECRUITING, startDateStruct date: 2024-06, primaryCompletionDateStruct date: 2028-06, completionDateStruct date: 2028-06, studyFirstPostDateStruct date: 2024-04-02, lastUpdatePostDateStruct date: 2024-04-02, sponsorCollaboratorsModule leadSponsor name: University Hospital, Basel, Switzerland, class: OTHER, descriptionModule briefSummary: Researchers will test a new treatment for prostate cancer. This treatment uses an antibody tagged with a small amount of radioactive material. Researchers believe the new antibody might work better than those used before.In the first part of the study researchers will compare the new treatment to the old one on prostate cancer patients using very low doses, not strong enough to treat nor to cause strong adverse reactions. Each patient will eventually receive both treatments, but one at a time.The aim of the second part of the study is to find the best dose of the new treatment for patients. This means finding the dose that offers the most benefits with the fewest side effects.The performance of different prostate cancer diagnostic methods is also in scope of the study., conditionsModule conditions: Castration-resistant Prostate Cancer, designModule studyType: INTERVENTIONAL, phases: PHASE1, designInfo allocation: RANDOMIZED, interventionModel: CROSSOVER, interventionModelDescription: In Phase Ia:Radiation dosimetry driven, head-to-head in cross-over design comparison of tumour and critical organ absorbed doses after sequential non-therapeutic injections of 161Tb-SibuDAB and 177Lu-PSMA-I\&T in the same mCRPC patients undergoing standard 177Lu-PSMA-I\&T RLT.In Phase Ib:Clinical and radiation dosimetry-based dose escalation study, with a classical 3+3 design, to identify the optimal biologic dose (injected activity) of 161Tb-SibuDAB for safe and effective RLT., primaryPurpose: TREATMENT, maskingInfo masking: SINGLE, whoMasked: PARTICIPANT, enrollmentInfo count: 25, type: ESTIMATED, armsInterventionsModule interventions name: Injection, 161Tb-SibuDAB,1GBq, interventions name: Injection, 177Lu-PSMA-I&T, 1GBq, interventions name: Injection, 161Tb-SibuDAB, Dose Escalation, outcomesModule primaryOutcomes measure: Phase Ia: Tumour absorbed dose, primaryOutcomes measure: Phase Ib: Identification of the optimal biological dose of 161Tb-SibuDAB for mCRPC RLT, secondaryOutcomes measure: Phase Ia: Estimation of critical organ median absorbed doses, secondaryOutcomes measure: Phase Ia: Estimation of the median tumour-to-critical organ absorbed dose ratios, secondaryOutcomes measure: Phase Ib: Cumulative median tumour and organ absorbed doses after 4 cycles of 161Tb-SibuDAB RLT, secondaryOutcomes measure: Phase Ib: Estimation of the "therapy index" for 161Tb-SibuDAB RLT., eligibilityModule sex: ALL, minimumAge: 18 Years, stdAges: ADULT, stdAges: OLDER_ADULT, contactsLocationsModule locations facility: University Hospital Basel, city: Basel, zip: 4031, country: Switzerland, contacts name: Alin Chirindel, MD, role: CONTACT, phone: +41 61 328 63 75, email: alin.chirindel@usb.ch, contacts name: Guillaume Nicolas, MD, role: CONTACT, phone: +41 61 265 47 02, email: guillaume.nicolas@usb.ch, geoPoint lat: 47.55839, lon: 7.57327, hasResults: False