Study Evaluating Dosimetry, Randomized Dose Optimization, Dose Escalation and Efficacy of Ac-225 Rosopatamab Tetraxetan in Participants With PSMA PET-Positive Castration-Resistant Prostate Cancer (CRPC)
This is not medical advice. AI-assisted translation — inaccuracies may occur. Always verify the original and consult your oncologist before taking any steps.
About the trial
This is a four-part study evaluating the safety and efficacy of a PSMA-directed radioantibody (rosopatamab tetraxetan, conjugated to either In-111 or Ac-225). Part 1 will consist of one administration of In-111-rosopatamab tetraxetan to characterize the biodistribution of the radioantibody to target organs and prostate cancer lesions. Participants then will be enrolled into either Part 2 (Dose Optimization) or Part 3 (Dose Escalation and Expansion) depending on their prior treatment history. Part 4 will be an extended regimen in dose escalation and expansion. Participants qualifying for Part 2 will be randomized to receive Ac-225 rosopatamab tetraxetan in a single fractionated cycle (dose administration on Day 1 and Day 15) at either 45 or 60 kBq/Kg. Participants qualifying for Part 3 must have received prior Lu-177-PSMA-radioligand therapy and will receive Ac-225 rosopatamab tetraxetan in a single fractionated cycle at 45, 55, or 60 kBq/Kg. Dose limiting toxicities (DLTs) will be monitored in Part 3 to determine the recommended phase 2 dose (RP2D), and the study may enroll additional participants to be treated with the RP2D dose level. Participants qualifying for Part 4 will initially receive two doses (dose administration on Day 1 and Day 15) at the dose level selected in Part 2, followed by a single third dose of Ac-225 rosopatamab tetraxetan administered approximately 12 weeks after completion of the Part 2 fractionated dosing regimen. The starting dose level for Part 4 will be 22 kBq/kg (or fixed activity equivalent). Dose limiting toxicities (DLTs) will be monitored following administration of the third dose in Part 4 to determine the recommended phase 2 dose (RP2D) of a third dose of Ac-225 rosopatamab tetraxetan. Participants enrolled into any part will attend study visits which will include blood samples, electrocardiogram (ECG), radiographic imaging, and physical examinations along with other assessments.
Original English text from ClinicalTrials.gov
Who can (and can't) join
✓ Qualifies
- •Zaawansowany rak prostaty, który nie reaguje na terapię hormonalną (CRPC)
- •Rak prostaty rozprzestrzenit się na inne części ciała (przerzuty)
- •Nowotwór wykryty w badaniu PSMA PET
- •Wcześniejsze leczenie lekami hormonalnymi i co najmniej jednym lekiem z grupy ARSI
- •Bezwzględne leczenie ochronne kości (zoledronian lub denosumab) przez co najmniej 4 tygodnie
- •Osoby z HIV mogą uczestniczyć, jeśli wirus jest kontrolowany (poniżej 50 kopii/mL w ciągu ostatnich 6 miesięcy)
Simplified criteria — AI translation
Trial details
- Minimum age
- 18 Years
- Last updated (source)
- July 20, 2026
- Sex
- Male only
Therapies / drugs in trial
Locations (9)
University of California San Diego
San Diego, United States
Dana-Farber Cancer Institute
Boston, United States
Washington University in St. Louis
St Louis, United States
X Cancer Omaha / Urology Cancer Center
Omaha, United States
Laura & Isaac Perlmutter Cancer Center
New York, United States
Memorial Sloan Kettering Cancer Center
New York, United States
New York Presbyterian/Weill Cornell Medical Center
New York, United States
Duke University Medical Center
Durham, United States
The Cleveland Clinic Foundation
Cleveland, United States
Trial contact
Study Director
Contact information from ClinicalTrials.gov. Contact in English.
Share this trial
Data from ClinicalTrials.gov. AI-assisted translation, last sync: 7/21/2026.
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