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Trial Targeting Gut Bacterial Androgen Production to Reverse Therapeutic Resistance to Abiraterone in Patients With Metastatic Prostate Cancer

Phase II Trial Targeting Gut Bacterial Androgen Production to Reverse Therapeutic Resistance to Abiraterone in Patients With Metastatic Prostate Cancer

Status
Recruiting
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT06616597
Enrollment
58
Registered
2024-09-27
Start date
2025-02-13
Completion date
2032-03-30
Last updated
2026-02-19

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Metastatic Prostate Cancer, Prostate Cancer (Adenocarcinoma)

Keywords

Abiraterone, microbiome, Dexamethasone

Brief summary

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.

Interventions

DRUGAbiraterone acetate

Abiraterone acetate 1000mg/ day

DRUGDexamethasone

Dexamethasone 0.5mg/day

DRUGMetronidazole

Metronidazole 1500mg/ per day

Sponsors

Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins
Lead SponsorOTHER
United States Department of Defense
CollaboratorFED
Prostate Cancer Foundation
CollaboratorOTHER

Study design

Allocation
NON_RANDOMIZED
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
MALE
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* 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 * 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

Exclusion criteria

* 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 * 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.

Design outcomes

Primary

MeasureTime frameDescription
Number of participants with PSA30 response24 weeksNumber of participants with castration resistant prostate cancer who have a ≥ 30% decline in PSA from baseline until 24 weeks.

Secondary

MeasureTime frameDescription
Number of participants with PSA50 response12 weeksNumber of participants with castration resistant prostate cancer who have a ≥ 50% decline in PSA from baseline until 12 weeks.
PSA Progression Free Survival12 weeksNumber of participants with PSA progression according to PCWG3 (25% rise in PSA from nadir and increase of at least 2ng/mL)
Number of participants with progression24 weeksprogression 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.
Number of grade 3-5 toxicities24 weeksToxicity is evaluated based on current CTCAE standard grading scales.

Countries

United States

Contacts

CONTACTDonna Bieg, RN
dieg2@jhmi.edu410-502-7635
PRINCIPAL_INVESTIGATORCatherine Handy Marshall, M.D.

Johns Hopkins University

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 20, 2026