A Study Testing if Patients With Advanced Prostate Cancer Who Are Responding Well to Combination Treatment Can Safely Reduce Their Medication to a Single Hormone Therapy, Compared to Continuing Their Current Drugs
Castration Sensitive Prostate CancerMetastatic Prostate Cancer
Investigational drug(s) / intervention(s)
De-escalation strategyContinuation of initial Androgen Deprivation Therapy (ADT) and Androgen Receptor Pathway Inhibitor (ARPI) combination therapy at standard doses
De-escalation strategy: The experimental intervention is a response-adapted de-escalation to Androgen Deprivation Therapy (ADT) monotherapy, achieved by completely discontinuing Androgen Receptor Pathway Inhibitor (ARPI) treatment (and associated corticosteroids). This de-escalation is initiated only after patients complete a 6-to-7-month run-in phase of standard doublet or triplet therapy.
Continuation of initial Androgen Deprivation Therapy (ADT) and Androgen Receptor Pathway Inhibitor (ARPI) combination therapy at standard doses: Arm-A serves as the standard-of-care control arm, in which patients continue their intensified combination therapy despite having achieved a deep clinical and molecular response. The intervention strictly involves continuing the identical Androgen Deprivation Therapy (ADT) and Androgen Receptor Pathway Inhibitor (ARPI) regimen-such as abiraterone, enzalutamide, apalutamide, or darolutamide-administered during the 6-to-7-month run-in phase, maintained at original doses.
Study summary
The goal of this randomized comparative study (a study where participants are placed into groups by chance) is to find out if reducing treatment to androgen deprivation therapy (ADT)-a treatment that lowers testosterone-by itself works just as well as continuing the original combination of drugs. This study involves adult men with metastatic hormone-sensitive prostate cancer (prostate cancer that has spread to other parts of the body but still responds to hormone treatments) who have responded very well after 6 to 7 months of their initial two-drug or three-drug treatment.
The main questions it aims to answer are:
1. Does reducing treatment to ADT alone work as well as the combination treatment at keeping the cancer from growing on imaging scans after 18 months, also known as radiographic progression-free survival (rPFS)?
2. Does reducing treatment to ADT alone work as well as the combination treatment at preventing a rise in prostate-specific antigen (PSA), known as PSA progression-free survival (PSA-PFS)?
Researchers will compare a continuation group, which continues their initial two-drug or three-drug treatment, to a reduced-treatment group, which stops taking the androgen receptor pathway inhibitor (ARPI)-a drug that blocks the effects of hormones on cancer cells. Researchers want to see if reducing the treatment safely controls the cancer while lowering drug side effects and financial costs.
Participants will:
1. Complete a 6- to 7-month initial period receiving a two-drug or three-drug treatment chosen by their doctor.
2. Have blood tests for PSA and testosterone, and undergo a specialized imaging scan called a prostate-specific membrane antigen positron emission tomography/computed tomography (PSMA PET/CT) scan, to confirm the treatment is working very well before being assigned to a study group.
3. Stop taking the ARPI drug if assigned to the reduced-treatment group, or continue their current medications if assigned to the continuation group.
4. Go to check-up visits every 3 months for the first 24 months to complete physical exams, blood tests, and quality-of-life surveys.
5. Have a PSMA PET/CT scan every 6 months after being put into a group to check if the cancer has grown.
Eligibility
Sex
MALE
Min age
18 Years
Max age
80 Years
Healthy volunteers
No
Inclusion Criteria:
Inclusion criteria for enrolment:
1. All patients of age group 18 to 80 years will be included
2. Patients who would voluntarily agree to sign informed consent form
3. Histologically confirmed adenocarcinoma of the prostate
4. Evidence of metastatic disease at diagnosis (de novo) or after definitive local therapy, documented on PSMA PET/CT
5. Intended to receive ADT plus an ARPI (abiraterone, enzalutamide, apalutamide or darolutamide) OR ADT plus ARPI plus docetaxel, as determined by the treating physician prior to enrolment
6. ECOG performance status 0-2
7. Adequate organ function: haemoglobin ≥ 9 g/dL; absolute neutrophil count ≥ 1.5 × 10⁹/L; platelets ≥ 100 × 10⁹/L; serum creatinine ≤ 1.5 × ULN or estimated GFR ≥ 45 mL/min; total bilirubin ≤ 1.5 × ULN; AST/ALT ≤ 2.5 × ULN
8. Life expectancy ≥ 12 months
Criteria for randomization ("optimal responder"):
1. Completion of 6-7 months of protocol-defined doublet or triplet therapy without unplanned interruption \> 30 days
2. Serum PSA \< 0.2 ng/mL at re-staging
3. Serum testosterone at castrate level (\< 50 ng/dL)
4. PSMA PET/CT demonstrating partial or complete response as per PPP criteria: (i) no new PSMA-avid lesions; (ii) \> 30 % decrease in total PSMA tumour volume compared with baseline; and (iii) no progression at existing sites
5. ECOG 0-2 at re-staging
6. Adequate organ function (as at baseline)
7. Ongoing willingness to participate and to comply with randomized treatment
Exclusion Criteria:
Exclusion criteria for enrolment:
1. Known small-cell, neuroendocrine or predominantly sarcomatoid histology
2. Prior systemic therapy for prostate cancer other than ≤ 90 days of ADT (± a short course of first-generation anti-androgen for flare prevention) at enrolment
3. Prior treatment with any ARPI, docetaxel, cabazitaxel, Ra-223 or 177Lu-PSMA
4. Uncontrolled hypertension (systolic ≥ 160 mm Hg or diastolic ≥ 100 mm Hg despite therapy), history of seizures or predisposing conditions (for enzalutamide candidates), unstable cardiac disease, recent myocardial infarction or stroke within 6 months
5. Known active second malignancy requiring systemic therapy (except adequately treated non-melanoma skin cancer)
6. Active uncontrolled infection including HIV, hepatitis B or C with detectable viral load, or tuberculosis on active treatment
7. Any contraindication to the chosen ARPI, docetaxel or ADT per respective product labels
8. Psychiatric or cognitive disorder limiting capacity to consent or comply with protocol
Exclusion criteria at randomization:
1. Serum PSA ≥ 0.2 ng/mL or any PSA rise above nadir of ≥ 25 %
2. Any new lesion on PSMA PET or conventional imaging
3. Progression at existing sites per PCWG4 or PPP
4. Testosterone ≥ 50 ng/dL (non-castrate)
5. Development of symptomatic disease (e.g. new bone pain requiring opioid therapy, cord compression, pathological fracture)
6. Grade ≥ 3 ongoing toxicities attributable to current therapy that precludes continuation
7. Withdrawal of consent
Primary outcome measure(s)
18-month radiographic progression-free survival (rPFS) — Assessed from the date of randomization up to 18 months, with routine PSMA PET/CT imaging conducted every 6 months (patients without an event at 18 months are censored at their last assessment) Time from randomization to the earliest of: radiographic progression per PCWG4 on PSMA PET; unequivocal progression on PSMA PET (≥ 2 new lesions or PPP progression); or death from any cause. Patients without an event at 18 months are censored at last assessment.
PSA progression-free survival — Assessed from the time of randomization until confirmed PSA progression or death, evaluated every 3 months for the first 24 months and every 6 months thereafter, through the total follow-up period (minimum 24 months post-randomization; up to 60 months) Time from randomization to confirmed PSA progression per PCWG4 (≥ 25 % rise and ≥ 2 ng/mL above nadir, confirmed ≥ 3 weeks later), or death
Trial sites (1)
Facility
City
Region
Status
Kokilaben Dhirubhai Ambani Hospital and Medical Research Institute
Mumbai
Maharashtra
Official registry record
This page summarises publicly available registry data for informational purposes — not medical advice. Eligibility is determined by each study team; patients should discuss participation with their clinician.
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