Actively Recruiting
A Phase 1/2a Study to Evaluate Safety, Distribution, and Preliminary Activity of 161Tb-RAD402 Targeting PSA in Men With Castration-Resistant Prostate Cancer
Led by Radiopharm Theranostics, Ltd · Updated on 2026-04-01
73
Participants Needed
2
Research Sites
17 weeks
Total Duration
On this page
AI-Summary
What this Trial Is About
Researchers are evaluating 161Tb-RAD402, a radiolabeled monoclonal antibody targeting free prostate-specific antigen, in men with castration-resistant prostate cancer (CRPC). This Phase 1/2a study aims to assess the safety, tolerability, whole-body distribution, pharmacokinetics, radiation dosimetry, and preliminary anti-tumor activity of 161Tb-RAD402. The study also seeks to determine the maximum tolerated dose and recommended Phase 2 dose for this treatment in participants with locally advanced or metastatic CRPC who have progressed after prior therapies. The study has two parts: Phase 1 involves dose escalation to establish safety and dosing using a Bayesian Optimal Interval design; Phase 2a is a dose expansion phase at the recommended dose to confirm safety and evaluate preliminary anti-tumor effects using a Bayesian beta-binomial design based on prostate-specific antigen (PSA) response. Participants receive 161Tb-RAD402 administered at treatment doses, and the study is an open-label, single-arm trial. Participants will go through a screening period, followed by treatment and imaging periods, and then safety and long-term follow-up. Researchers will monitor adverse events, pharmacokinetics, biodistribution, radiation dosimetry, and biochemical responses including PSA levels. Follow-up and assessments are conducted up to 30 weeks post-treatment to evaluate tumor activity and safety outcomes, with ongoing monitoring for side effects and treatment tolerability.
CONDITIONS
Brief Title
A Study of Terbium 161 (161Tb)-RAD402 in Participants With CRPC
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Male participants 18 years of age or older
- Histopathologically confirmed locally advanced or metastatic castration-resistant prostate cancer (CRPC)
- Documented disease progression during or after most recent anticancer therapy
- PSMA PET-positive metastatic lesions with at least one lesion showing higher uptake than liver
- Prior treatment with androgen deprivation therapy and at least one androgen receptor signaling inhibitor
- ECOG performance status of 0 or 1
- Life expectancy of at least 4 months
- Willing to provide informed consent and comply with study procedures
- Prior treatment with up to 6 doses of lutetium-177 PSMA radioligand allowed
- Prior taxane-based chemotherapy (minimum two cycles) allowed but not required
- Participants with stable, treated brain metastases meeting specific neurologic criteria
You will not qualify if you...
- Prostate cancer with significant sarcomatoid, spindle cell, neuroendocrine small cell components, or other cancer metastasis to prostate
- History of prior organ transplant (except corneal transplant)
- Active malignancy other than non-melanoma skin cancer or treated low-risk bladder cancer
- Medical conditions preventing full study participation, such as severe claustrophobia or inability to lie still for imaging
- Residual toxicity grade 2 or higher from prior therapies (except alopecia and peripheral neuropathy)
- Uncontrolled allergic reactions or hypersensitivity to study drug or components
- Inadequate organ function based on specified laboratory values
- Need for blood transfusion within 2 weeks before first study dose
- Significant cardiovascular disease including recent myocardial infarction, unstable angina, or heart failure NYHA class II or above
- Participation in other investigational trials for the same cancer at consent
- Major surgery within 4 weeks before first dose
- Prior therapy with PARP inhibitors or radium Ra 223 dichloride
- Recent anticancer therapies within 28 days before first dose
- Known active hepatitis B or C infection
- Uncontrolled infections or illnesses
- Untreated moderate to severe hydronephrosis
- Superscans on bone scan
- Active autoimmune disease requiring systemic treatment within 90 days
- Other significant comorbidities that may affect safety or study compliance
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
Your Study Journey
Duration - 2 to 4 weeks
Participants are screened for eligibility to participate in the trial.
1 visit (in-person)
Duration - Up to 30 weeks
Participants receive 161Tb RAD402 at escalating doses in Phase 1 to determine the maximum tolerated dose and recommended Phase 2 dose, followed by treatment at the recommended dose in Phase 2a to evaluate preliminary anti-tumor activity.
Multiple visits during treatment and imaging periods
Duration - Up to 30 weeks
Participants are monitored for safety, pharmacokinetics, radiation dosimetry, biodistribution, and long-term outcomes after treatment with 161Tb RAD402.
Follow-up visits as scheduled post-treatment
Trial Site Locations
Total: 2 locations
1
Wollongong Hospital
Wollongong, New South Wales, Australia, 2500
Actively Recruiting
2
Icon Cancer Centre Hollywood
Nedlands, Western Australia, Australia, 6009
Actively Recruiting
Research Team
D
Dimitris Voliotis, MD
How is the study designed?
Study Type
INTERVENTIONAL
Masking
NONE
Allocation
NA
Model
SINGLE_GROUP
Primary Purpose
TREATMENT
Number of Arms
1
Similar Trials
Frequently Asked Questions
Have more questions? Get in touch with our team for quick support
Not the Right Trial for You?
Explore thousands of other clinical trials that might be a better match.
Sign up to get personalized trial recommendations delivered to your inbox.
Already have an account? Log in here