Clinical trial Recruiting at 1 site Interventional Ages 18 and up Men only

7-day water-only fasting for metastatic prostate cancer

Official title: A Study of 7-days Water-only Fasting or Ketone Supplementation in Patients With Prostate Cancer

Run by Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins · NCT06826924 · Data updated 2026-11-12

This study will test whether a 7-day water-only fast (with a ketogenic very low-calorie option) is safe and doable for people with metastatic prostate cancer.

Quick facts

Study typeInterventional
Ages18 Years and up
SexMen only
Enrollment40 (estimated)
SponsorSidney Kimmel Comprehensive Cancer Center at Johns Hopkins
Academic / other
Locations1 site (Baltimore, Maryland)
StatusRecruiting
StartedJune 3, 2025
Main results expectedJune 3, 2027
Study endsJune 3, 2027
Registry record updatedJune 30, 2026
Trial IDNCT06826924 on ClinicalTrials.gov

Is this trial a fit for you?

Likely a good fit

Adults (≥18) with metastatic prostate adenocarcinoma, ECOG 0–1, BMI 20–35 kg/m2, a soft-tissue metastasis amenable to biopsy, and PSA that is not currently declining are ideal candidates.

Probably not a fit

Patients with poor performance status, BMI outside 20–35, uncontrolled comorbidities, ongoing required steroid therapy, or no biopsy-accessible metastasis are unlikely to benefit or be eligible.

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

Participants with metastatic prostate adenocarcinoma will attempt a 7-day water-only fast followed by a 3-day supervised refeeding period, with the option to switch to a ketogenic very low-calorie diet during the fasting window. The protocol includes regular laboratory monitoring and a clinic visit on Day 3, and requires a soft-tissue metastasis that can be biopsied for correlative studies. The main goals are to determine safety and feasibility of the fasting intervention in this patient population and to collect biological samples to study immune and metabolic changes. Prior cancer treatments are allowed if sufficiently remote, and steroid use must be stopped before enrollment.

Why it matters

Potential benefit: If successful, this approach could enhance anti-tumor immune activity and help make existing prostate cancer treatments more effective for some patients.

How similar studies have gone: Short-term fasting has shown immune and anti-tumor effects in animal models and is safe in healthy adults, but controlled data in metastatic prostate cancer patients are limited and largely untested.

Who can join: the full rules

Show full inclusion / exclusion criteria
Inclusion criteria:

* Eastern Cooperative Oncology Group (ECOG) Performance Status 0 or 1
* Age ≥18 years
* Diagnosis of adenocarcinoma of the prostate
* If a soft tissue metastasis amenable to biopsy is present, then the participant must agree to biopsies.
* If the participant has local prostate cancer, then the participant must agree to prostate biopsy or radical prostatectomy on days 8, 9, or 10. -. Prostate-specific antigen (PSA) is not currently declining, as determined by most recent 2 measurements taken at least 1 week apart in previous 2 months.
* BMI between 20 and 35 kg/m2
* Prior treatment with any prostate cancer therapy is permitted if \>2 weeks from last dose. Patients are not required to have received prior treatment for prostate cancer.
* Prior treatment with steroids is permitted if \>2 weeks from last dose. Patients who cannot be weaned off steroids are not eligible.
* Acceptable liver function:

  1. Bilirubin \< 2.5 times institutional upper limit of normal (ULN)
  2. Aspartate transaminase (AST) (SGOT) and Alanine transaminase (ALT) (SGPT) \< 2.5 times ULN
* Acceptable renal function: glomerular filtration rate (GFR) of 50 mL/min/1.73 m2 or higher. GFR will be estimated by the 2021 chronic kidney disease epidemiology (CKD-EPI) creatinine equation1 using the online calculator found on UpToDate.
* Acceptable hematologic status:

  1. Absolute neutrophil count (ANC) ≥ 1500 cells/mm3 (1.5 ×109/L)
  2. Platelet count ≥ 100,000 platelet/mm3 (100 ×109/L)
  3. Hemoglobin ≥ 8 g/dL.
* Acceptable electrolyte and acid/base status:

  1. Sodium 135-148 millimoles (mM)
  2. Potassium 3.5-5.1mM
  3. Carbon Dioxide 21-31mM
  4. Phosphorus 2.7-4.5mM
  5. Magnesium ≥1.6mM
  6. Lactate ≤2mM
* Ability to understand and willingness to sign a written informed consent document

Exclusion criteria:

* ECOG Performance status ≥2
* Unintentional weight loss greater than or equal to 5% in previous 3 months
* Diabetes mellitus, defined as HbA1c ≥6.5% or use of medications for diabetes
* Active uncontrolled infection. Patients with a history of HIV/AIDS may be eligible if CD4+ T cell counts are ≥ 350 cell/ul, the patients have had no opportunistic infection within the past 12 months, they have been on established antiretroviral therapy (ART) for at least four weeks, and the HIV viral load is less than 400 copies/ml prior to enrollment. Patients with a history of hepatitis C virus (HCV) infection are eligible if the patients have completed curative antiviral treatment and the HCV viral load is below the limit of quantification.
* Use of immunosuppressive medications including steroids
* Use of diuretics or beta blockers
* History of cardiac arrythmia, myocardial infarction, valvular heart disease, or pulmonary hypertension
* Abnormal screening EKG
* Daily alcohol consumption
* Any condition or mental impairment that may compromise the ability to give informed consent, patient's safety or compliance with study requirements as determined by the investigator

Where it's running

  • Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins
    Baltimore, Maryland, United States
    Recruiting

Study contacts

  • Principal investigator: Laura Sena, MD, PhD — SKCCC Johns Hopkins Medical Institution
  • Study coordinator: Laura Sena, MD, PhD
  • Email: laura.sena@jhmi.edu
  • Phone: 410-502-3825

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

How to take part

  1. Review the eligibility criteria above with your treating physician.
  2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
  3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.
Last reviewed 2026-11-14 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.