Could a hormone Flip-Flop tame tough prostate cancer?
NCT ID NCT05081193
First seen Jun 24, 2026 · Last updated Jun 26, 2026 · Updated 1 time
Summary
This study tested a two-step treatment in 15 men with metastatic castration-resistant prostate cancer. First, they took high-dose oral testosterone for three 28-day cycles. If the cancer grew, they switched to enzalutamide. The goal was to see if oral testosterone could control the cancer as well as injected testosterone, and whether the sequence might improve outcomes.
What this could mean
Our plain-language read of the trial. This is informational only, not medical advice or a prediction.
- Active substance
- testosterone undecanoate (Jatenzo) and enzalutamide (Xtandi)
- What this could lead to
- If it works, this could point toward a new treatment sequence that uses high-dose oral testosterone to control prostate cancer before switching to enzalutamide.
- What could go wrong
- This is a very small, early-phase study (15 men) with no control group. The approach is experimental and may not provide lasting benefit or work for most patients.
This is an AI summary of the original study and may miss details. Read our disclaimer.
Study facts
What this study's own registry entry says, in plain language.
- Phase
-
Phase 2
Tests whether the treatment actually works, and watches for side effects, in a larger group.
- Participants
-
15 people
The number who actually took part.
- Started
-
Mar 2022
- Finished
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Aug 2025
- Lead sponsor
-
Other sponsor
The registry's catch-all category, for sponsors it does not file as a company, a government agency, or a research network.
Who can take part
This study's own entry requirements. Only the study team can say for certain whether you qualify.
- Ages
-
18 years and older
- Sex
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Male participants only
- Healthy volunteers
-
Not accepted
This study is not open to healthy volunteers. The entry requirements below say who it is open to.
Show the full entry requirements Hide the full entry requirements
Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.
Inclusion Criteria: * Patient has the ability to understand and willingness to sign a written informed consent document. * Patient is a male aged 18 years or older. * Patient has histologically-confirmed adenocarcinoma of the prostate * Patient has an Eastern Cooperative Oncology Group (ECOG) performance status of ≤2 (as defined in Appendix A: Performance Status Criteria; * Patient has evidence of metastatic, measurable disease by CT scan. Measurable disease is defined by RECIST 1.1 as at least one measurable lesion ≥10mm by CT scan * Patient is progressing on continuous androgen ablative therapy (either surgical castration or LHRH agonist/antagonist) * Patient has documented castrate level of serum testosterone (\<50 ng/dl) * Patient is progressing on luteinizing hormone-releasing hormone (LHRH) agonist/antagonist plus anti-androgen or abiraterone for CSPC. (Note: Must be off anti-androgen or abiraterone for 4 weeks prior to first treatment with OT.) LHRH (luteinizing hormone-releasing hormone) * Patient has had prior docetaxel for CSPC. Note: Docetaxel is permitted if ≤ 6 doses were given in conjunction with first-line androgen deprivation therapy and \>6 months since last dose of docetaxel. (CSPC-castrate sensitive prostate cancer) * Patient is currently taking prednisone and cannot be weaned entirely off. Note: Patient's dose must be maintained on lowest stable dose that relieves symptoms. Patient is receiving prednisone in conjunction with abiraterone acetate must be weaned off prednisone if possible prior to starting OT. * Patient has had a rising PSA on two successive measurements at least two weeks apart. * Patient agrees to continue on castrating therapy throughout OT treatment. * Patient's screening lab values are within the following parameters: 1. Absolute neutrophil count (ANC) ≥ 1500 cells/mm3 (1.5 ×109/L) 2. Platelet count ≥ 100,000 platelet/mm3 (100 ×109/L) 3. Hemoglobin ≥ 9 g/dL 4. Serum creatinine \< 2.5 times ULN 5. Bilirubin \< 2.5 times institutional upper limit of normal (ULN) 6. Aspartate aminotransferase (AST) and Alanine Aminotransferase (ALT) \< 2.5 times ULN * Patient has had surgery, has completed at least 4 weeks of recovery and has no persistent toxicity \> grade 1. Exclusion Criteria: * Patient has pain due to metastatic prostate cancer requiring opioid analgesics. * Patient has had prior treatment with any agent for metastatic castration-resistant prostate cancer. (Includes docetaxel, cabazitaxel, anti-androgen, abiraterone, or investigational agents) * Patient requires urinary catheterization for voiding due to obstruction secondary to prostatic enlargement thought to be due to prostate cancer or benign prostatic hyperplasia. Note: Patients with indwelling catheter/suprapubic catheter to relieve obstruction are eligible. * Patient has evidence of disease in sites or extent that, in the opinion of the investigator, would put the patient at risk from therapy with testosterone (e.g. femoral metastases with concern over fracture risk, epidural spinal metastases with concern over spinal cord compression, lymph node disease with concern for ureteral obstruction). * Patient has evidence of disease in sites or extent that, in the opinion of the investigator, would put the patient at risk from therapy with testosterone (e.g. femoral metastases with concern over fracture risk, epidural spinal metastases with concern over spinal cord compression, lymph node disease with concern for ureteral obstruction). * Patient has active uncontrolled infection, such as HIV/AIDS or chronic hepatitis B or untreated chronic hepatitis C. * Patient has had prior history of a thromboembolic event within the past two years and not currently on systemic anticoagulation. * Patient is on Coumadin. Note: If anticoagulation therapy is mandatory, patient must be switched to an alternative medication) Patients receiving anticoagulation therapy with warfarin, rivaroxaban or apixaban are not eligible for study. \[Patients on enoxaparin or edoxaban are eligible for study. Patients on warfarin, rivaroxaban or apixaban, who can be transitioned to enoxaparin prior to starting study treatments, will be eligible. * Patient has hematocrit \>50%, untreated severe obstructive sleep apnea, uncontrolled or poorly controlled heart failure \[per Endocrine Society Clinical Practice Guidelines\].
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Conditions
The condition(s) this trial relates to.
As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
Contacts and locations
Locations
-
Allegheny Health Network
Pittsburgh, Pennsylvania, 15212, United States
-
Johns Hopkins Hospital
Baltimore, Maryland, 21231, United States
More trials for these conditions
Other studies related to the condition(s) this trial covers.
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