Phase 2 Randomized Trial of Flexible Dosing Schedule of 177Lu-PSMA-617 for the Treatment of Metastatic Castration-Resistant Prostate Cancer (FLEX-MRT)
A Phase 2 Randomized Trial in Patients With Metastatic Castration Resistant Prostate Cancer to Determine the Efficacy of a Flexible Dosing Schedule of Lu-PSMA Treatment up to 12 Cycles Including Potential Treatment Holiday Periods in Comparison to the Standard Fixed Dosing Schedule of Six Cycles Every Six Weeks (FLEX-MRT)
Who can join
As published by the study on ClinicalTrials.gov. "Not stated" means the study hasn't said — ask the study team.
- Age
- 18 Years and older
- Sex
- Male only
- Healthy volunteers
- Not accepted
- Compensation
- Not stated
Other requirements are listed under Eligibility below. Only the study team can confirm whether you can join.
What to expect
No one can promise a trial will help you personally — that is what the research is trying to find out.
What participation involves
- Time periods mentioned: 24 months
- Procedures mentioned: CT scans, Injections
Only what the study's summary and detailed description on ClinicalTrials.gov say. Time periods may describe the whole study or a part of it — ask the study team what applies to you.
Show the study's own words
- "The flexible dosing schedule in the investigational arm will be based on single photon emission computed tomography (SPECT)/computed tomography (CT) response assessments obtained 24h after injection of LuPSMA therapy cycle."
- "The response assessment during treatment holiday period will be based on positron emission tomography/computed tomography (PET/CT) every 12 weeks."
- "The flexible dosing schedule in the investigational arm will be based on prostate specific antigen (PSA) and SPECT/CT response assessments obtained 24h after injection of LuPSMA therapy cycle."
- "Upon completion of study treatment, patients are followed up every 3 months for 24 months from after first cycle of study treatment."
- Compensation
- Not stated
- Study-related exams and procedures are typically provided at no cost. This is how many trials work in general — confirm the details for this study with the study team.
- Participants are monitored closely by the research team throughout the study.
- Some participants may receive access to an investigational treatment, which is still being studied.
- Your participation helps researchers learn whether this approach could help future patients.
About this study
In plain language
This study tests a flexible schedule of 177Lu-PSMA-617, a radiation treatment, for prostate cancer that has spread and no longer responds to treatment that lowers male hormones. It is for people who have already had chemotherapy and a drug that blocks male hormone signals. The study compares up to 12 treatments with possible breaks to the usual schedule of up to 6 treatments, given every 6 weeks.
In advanced metastatic castration resistant prostate cancer (mCRPC) progressing after chemotherapy and androgen receptor (AR)-targeted therapy 177Lu-PSMA-617 is an effective treatment. 177Lu-PSMA-617 RLT is administered with a fixed schedule: 6 treatment cycles, administered every 6 weeks. However, the optimum number of cycles of 177Lu-PSMA in patients who show good response remains unknown. Some patients may benefit from more than 6 cycles of therapy. Additionally, some patients experience a complete or almost complete response before the last cycle. It is unclear whether these patients benefit from the subsequent remaining treatment cycle(s). A treatment holiday period would spare these patients some exposure to the therapy agent and avoid potentially unnecessary toxicity when treatment efficacy is already maximal and additional treatment effect cannot be expected. This randomized phase 2 study compares a group of patients treated with LuPSMA on a flexible and extended dosing schedule including "treatment holiday" periods (investigational arm, up to 12 cycles, as described below) to a control group treated with a fixed dosing schedule of 6 treatments cycles maximum administered every 6 weeks. The flexible dosing schedule in the investigational arm will be based on single photon emission computed tomography (SPECT)/computed tomography (CT) response assessments obtained 24h after injection of LuPSMA therapy cycle. The response assessment during treatment holiday period will be based on positron emission tomography/computed tomography (PET/CT) every 12 weeks. Single-time point SPECT/CT dosimetry protocol at every cycle will be performed and will allow to determine the number of cycles that subjects may receive under the study without exceeding the kidney dose threshold.
Compensation is read from the study's own description and may be missing — always confirm with the study team.
Eligibility
Who can join
- Be age 18 or older.
- Have prostate cancer confirmed by a tissue test, with cancer spread to at least one site shown on a scan.
- Have had at least one chemotherapy treatment plan for prostate cancer that has spread and resists hormone-lowering treatment.
- Have had at least one drug that blocks male hormone signals.
- Have a PSMA PET/CT scan that meets the study’s rules within 8 weeks before the planned first treatment.
- Meet blood count limits: white blood cells at least 2,500/µL; platelets, which help blood clot, at least 100,000/µL; hemoglobin, which carries oxygen, at least 9.0 g/dL; and neutrophils, which fight infection, at least 1,500/µL.
- Have an ECOG activity score of 0–2: be able to care for yourself and be out of bed or a chair for more than half of waking hours.
- Be able to understand and sign the consent form and understand and follow all study rules.
Who can't join
- Have already received 177Lu-PSMA-617.
- Have less than 6 weeks between the last treatment that lowers blood cell production and the first study treatment. This includes certain chemotherapy and radiation treatments.
- Have a kidney filtering rate (GFR) below 50 mL/min.
- Have a blockage in urine flow or major kidney swelling caused by backed-up urine.
Simplified for readability. The official criteria below are what the study team uses.
Official eligibility criteria
Inclusion Criteria: * Patients must have prostate cancer proven by histopathology * Patients must have ≥ 1 metastatic lesion by any imaging (CT, magnetic resonance imaging \[MRI\], bone scan, PET) * Patients must have received at least one regimen of chemotherapy for mCRPC * Patients must have received at least one androgen-receptor signaling inhibitors (ARSI) * Patients must be eligible by PSMA PET VISION criteria. PSMA PET/CT must be performed within 8 weeks of planned first cycle of 177Lu-PSMA-617 * White blood cell (WBC) ≥ 2,500/ul * Platelets (PLT) ≥ 100,000/ul * Hemoglobin (Hb) ≥ 9.0 g/dl * Absolute neutrophil count (ANC) ≥ 1,500 ul * Patients must have an Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2 * Patients must be adults ≥ 18 years of age * Patients must have the ability to understand and sign an approved informed consent form (ICF) * Patients must have the ability to understand and comply with all protocol requirements Exclusion Criteria: * Prior cycle of 177Lu-PSMA-617 therapy * Less than 6 weeks between last myelosuppressive therapy (including docetaxel, cabazitaxel, strontium-89, samarium-153, rhenium-186, rhenium-188, radium-223, hemi-body irradiation) and first cycle of 177Lu-PSMA-617 therapy * Glomerular filtration rate (GFR) \< 50 ml/min * Urinary tract obstruction or marked hydronephrosis
Study sites (1)
CA
- UCLA / Jonsson Comprehensive Cancer Center · Los Angeles, CA 90095Jeremie Calais · Study contact · 213-769-9636 · jcalais@mednet.ucla.eduJeremie Calais · Principal investigatorMore trials in Los Angeles