Prostate Cancer (Adenocarcinoma)Phase 2NCT06616597
Trial Targeting Gut Bacterial Androgen Production to Reverse Therapeutic Resistance to Abiraterone in Patients With Metastatic Prostate Cancer
A Phase 2 study testing Abiraterone acetate, Dexamethasone and Metronidazole in people with Prostate Cancer (Adenocarcinoma) and Metastatic Prostate Cancer, run by Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins at 1 site in United States.
Trial summary
To determine if dexamethasone or dexamethasone plus metronidazole restore sensitivity to abiraterone for the treatment of metastatic prostate cancer. Read more about this study
- Who is it for?
- Ages 18 years and older, men only
- Conditions the study is for
- Prostate Cancer (Adenocarcinoma), Metastatic Prostate Cancer
- What is being tested?
- Abiraterone acetate, Dexamethasone and Metronidazole
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 58 participants
- Where
- 1 siteUnited States
- Study dates
- 13 Feb 2025to 30 Mar 2032
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- Men only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Males aged 18 years of age and above.
- Prostate adenocarcinoma
- Absolute PSA ≥ 2.0 ng/mL at screening.
- PSA (+/- radiographic) progression after having been on abiraterone and prednisone for at least 12 weeks.
- Must be maintained on a GnRH analogue or have undergone orchiectomy.
- Participants must have a life expectancy ≥ 6 months
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- Ability to swallow study medication tablets
- Willing to abstain from alcohol during and for 14 days after treatment with metronidazole
- Willing and able to collect urine and stool samples per protocol
Who cannot join
- Active infection or other medical condition that would make dexamethasone use contraindicated
- Any chronic medical condition requiring a higher systemic dose of corticosteroid
- Pathological finding consistent with small cell carcinoma of the prostate
- Has imminent or established spinal cord compression based on clinical findings and/or MRI.
- Chronic liver disease with Child-Pugh class C cirrhosis (see calculator in protocol)
- Bilirubin \>3x ULN or AST and ALT \>5x ULN
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- Congenital prolonged QTc syndrome or QTc \> 500 msec (non-paced rhythm)
- History of pituitary or adrenal dysfunction
- Uncontrolled diabetes (Hemoglobin A1c \> 10%) or increasing doses of insulin within the past 4 weeks due to poorly controlled glucoses.
- Administration of an investigational therapeutic or invasive surgical procedure (not including surgical castration) within 30 days of Cycle 1 Day 1 or currently enrolled in an investigational drug study
- Any other serious illness or medical condition that would, in the opinion of the investigator, make this protocol unreasonably hazardous, including, but not limited to:
- Any uncontrolled major infection.
- Crohn's disease or ulcerative colitis.
- Known or suspected toxic megacolon and/or known small bowel ileus.
- Known allergy to any of the compounds under investigation.
- On antibacterial therapy within 30 days prior to administration of study treatment.
- Any condition or situation which, in the opinion of the investigator, would put the subject at risk, or interfere with the subject's participation in this study.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins
Baltimore, Maryland, 21231
Irina Rifkind, RN, 410-502-2043, Irifkin1@jhmi.edu
About this study
Official title: Phase II Trial Targeting Gut Bacterial Androgen Production to Reverse Therapeutic Resistance to Abiraterone in Patients With Metastatic Prostate Cancer
To determine if dexamethasone or dexamethasone plus metronidazole restore sensitivity to abiraterone for the treatment of metastatic prostate cancer.
Read the detailed description
To test whether giving dexamethasone with or without metronidazole in combination with abiraterone could help reverse resistance to abiraterone for patients with metastatic castration-resistant prostate cancer (mCRPC). Abiraterone and prednisone (AA/P) is a second-line therapy for mCRPC given when first-line androgen deprivation therapy fails. However, resistance to AA/P can develop. The investigators do not know exactly how cancer becomes resistant, but there is evidence that suggests it could be due to androgen production by the bacteria in your gut (gut microbiome). This study is focused on the gut microbiome as a source of androgen production that could cause AA/P resistance in mCRPC.
- Being tested
- Abiraterone acetate, Dexamethasone, Metronidazole
- Keywords
- Abiraterone, microbiome, Dexamethasone
- Medical subject headings
- Prostatic Neoplasms, Adenocarcinoma
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Abiraterone acetateDrug
Abiraterone acetate 1000mg/ day
DexamethasoneDrug
Dexamethasone 0.5mg/day
MetronidazoleDrug
Also called Flagyl
Metronidazole 1500mg/ per day
| Study group | Role | What they receive |
|---|---|---|
| Arm 1: Abiraterone + Dexamethasone | Experimental | Abiraterone acetate plus dexamethasone Receives: Drug: Abiraterone acetate; Drug: Dexamethasone |
| Arm 2: Abiraterone + Dexamethasone + metronidazole | Experimental | Abiraterone acetate plus dexamethasone plus metronidazole Receives: Drug: Abiraterone acetate; Drug: Dexamethasone; Drug: Metronidazole |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of participants with PSA30 response
Number of participants with castration resistant prostate cancer who have a ≥ 30% decline in PSA from baseline until 24 weeks.
Measured: 24 weeks
Secondary outcomes (4)
Number of participants with PSA50 response
Number of participants with castration resistant prostate cancer who have a ≥ 50% decline in PSA from baseline until 12 weeks.
Measured: 12 weeks
PSA Progression Free Survival
Number of participants with PSA progression according to PCWG3 (25% rise in PSA from nadir and increase of at least 2ng/mL)
Measured: 12 weeks
Number of participants with progression
progression is defined as:
- Progression of soft tissue lesions according to RECIST 1.1 Criteria.
- Progression of bone lesions detected with bone scan according to PCWG3 criteria.
- Radiologically-confirmed spinal cord compression or pathological fracture due to malignant progression, or other clinical event deemed to be cancer-related, or death.
Measured: 24 weeks
Number of grade 3-5 toxicities
Toxicity is evaluated based on current CTCAE standard grading scales.
Measured: 24 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted27 Sep 2024
- Study start13 Feb 2025
- Primary completion30 Mar 2031 (estimated)
- Study completion30 Mar 2032 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Prostate Cancer (Adenocarcinoma)Studies of the same condition, open and under way.
- More trials run by Sidney Kimmel Comprehensive Cancer Center at Johns HopkinsThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 58 participants (estimated)
Sponsor and investigators
- Sponsor type
- University, hospital or other
- Collaborators
- United States Department of Defense, Prostate Cancer Foundation
- Responsible party
- Sponsor
- Investigators
- Catherine Handy Marshall, M.D., Principal investigator, Johns Hopkins University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06616597
- Sponsor's protocol ID
- J2485
- Other IDs
- IRB00453879
- Status last verified
- Feb 2026
- First submitted
- 23 Sep 2024
- Last updated
- 19 Feb 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 19 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Phase II Trial Targeting Gut Bacterial Androgen Production to Reverse Therapeutic Resistance to Abiraterone in Patients With Metastatic Prostate Cancer
- ClinicalTrials.gov ID
- NCT06616597
- Acronym / sponsor ID
- J2485
- Keywords
- Abiraterone, microbiome, Dexamethasone
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 58 participants (estimated)
- Lead sponsor
- Sidney Kimmel Comprehensive Cancer Center at Johns HopkinsUniversity, hospital or other
- Collaborators
- United States Department of Defense, Prostate Cancer Foundation
- Study start
- 13 Feb 2025 (actual)
- Primary completion
- 30 Mar 2031 (estimated)
- Study completion
- 30 Mar 2032 (estimated)
- First posted
- 27 Sep 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
To determine if dexamethasone or dexamethasone plus metronidazole restore sensitivity to abiraterone for the treatment of metastatic prostate cancer.
Detailed description
To test whether giving dexamethasone with or without metronidazole in combination with abiraterone could help reverse resistance to abiraterone for patients with metastatic castration-resistant prostate cancer (mCRPC). Abiraterone and prednisone (AA/P) is a second-line therapy for mCRPC given when first-line androgen deprivation therapy fails. However, resistance to AA/P can develop. The investigators do not know exactly how cancer becomes resistant, but there is evidence that suggests it could be due to androgen production by the bacteria in your gut (gut microbiome). This study is focused on the gut microbiome as a source of androgen production that could cause AA/P resistance in mCRPC.
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Arm 1: Abiraterone + Dexamethasone | Experimental | Drug: Abiraterone acetate, Drug: DexamethasoneAbiraterone acetate plus dexamethasone |
| Arm 2: Abiraterone + Dexamethasone + metronidazole | Experimental | Drug: Abiraterone acetate, Drug: Dexamethasone, Drug: MetronidazoleAbiraterone acetate plus dexamethasone plus metronidazole |
Who may qualify
- Ages
- 18 years and older
- Sex
- Male only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (9 listed)
- Males aged 18 years of age and above.
- Prostate adenocarcinoma
- Absolute PSA ≥ 2.0 ng/mL at screening.
- PSA (+/- radiographic) progression after having been on abiraterone and prednisone for at least 12 weeks.
- Must be maintained on a GnRH analogue or have undergone orchiectomy.
Key exclusion criteria (17 listed)
- Active infection or other medical condition that would make dexamethasone use contraindicated
- Any chronic medical condition requiring a higher systemic dose of corticosteroid
- Pathological finding consistent with small cell carcinoma of the prostate
- Has imminent or established spinal cord compression based on clinical findings and/or MRI.
- Chronic liver disease with Child-Pugh class C cirrhosis (see calculator in protocol)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Abiraterone acetateAbiraterone acetate 1000mg/ day | Drug | Arm 1: Abiraterone + Dexamethasone, Arm 2: Abiraterone + Dexamethasone + metronidazole |
| DexamethasoneDexamethasone 0.5mg/day | Drug | Arm 1: Abiraterone + Dexamethasone, Arm 2: Abiraterone + Dexamethasone + metronidazole |
| MetronidazoleAlso: FlagylMetronidazole 1500mg/ per day | Drug | Arm 2: Abiraterone + Dexamethasone + metronidazole |
Primary outcome
Number of participants with PSA30 response
Time frame: 24 weeks
Number of participants with castration resistant prostate cancer who have a ≥ 30% decline in PSA from baseline until 24 weeks.
4 secondary outcomes
Number of participants with PSA50 response
Time frame: 12 weeks
PSA Progression Free Survival
Time frame: 12 weeks
Number of participants with progression
Time frame: 24 weeks
Number of grade 3-5 toxicities
Time frame: 24 weeks
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 19 Feb 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Catherine Handy Marshall, M.D. principal investigator
Johns Hopkins University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Abiraterone acetate, Dexamethasone and Metronidazole in people with Prostate Cancer (Adenocarcinoma) and Metastatic Prostate Cancer, run by Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 9 inclusion and 17 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 19 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Donna Bieg, RN (410-502-7635, dieg2@jhmi.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of participants with PSA30 response (time frame: 24 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 19 Feb 2026.