Adding docetaxel to hormone and androgen-blocking therapy for men with metastatic prostate cancer who have a weak PSA response

A Randomized Phase III Clinical Trial for the Addition of Docetaxel to Androgen Receptor Pathway Inhibitors in Patients With Metastatic Castration Sensitive Prostate Cancer and Suboptimal PSA Response

Phase 3 Interventional Canadian Cancer Trials Group · NCT06592924

This trial tests whether adding docetaxel to standard hormone and androgen-blocking therapy helps men with metastatic, castration-sensitive prostate cancer who still have a higher-than-expected PSA after 6–12 months of treatment.

Quick facts

PhasePhase 3
Study typeInterventional
Enrollment830 (estimated)
Ages18 Years and up
SexMale
SponsorCanadian Cancer Trials Group Research network
Drugs / interventionschemotherapy
Locations340 sites (Anchorage, Alaska and 339 other locations)
Trial IDNCT06592924 on ClinicalTrials.gov

What this trial studies

This is an international, multicenter, open-label, randomized Phase 3 trial that compares standard of care androgen deprivation therapy (ADT) plus an androgen-receptor pathway inhibitor (ARPI) versus the same regimen with added docetaxel chemotherapy. Eligible participants have metastatic castration-sensitive prostate adenocarcinoma and a suboptimal PSA response after 6–12 months of androgen-targeting therapy. Participants are randomized to receive ADT+ARPI alone or ADT+ARPI with scheduled docetaxel; ARPIs allowed include abiraterone, enzalutamide, apalutamide, or darolutamide. The trial enrolls patients who are chemotherapy candidates with ECOG 0–2 and requires biochemical and organ-function eligibility screening.

Who should consider this trial

Good fit: Men with histologically confirmed metastatic castration-sensitive prostate adenocarcinoma who have been on ADT for 6–12 months and an ARPI for at least 4 months but still have a suboptimal PSA (≥0.2 ng/mL) and are candidates for docetaxel chemotherapy are ideal candidates.

Not a fit: Patients who have achieved a good PSA response to ADT+ARPI, who are not candidates for chemotherapy, or who do not have metastatic disease are unlikely to benefit from this approach.

Why it matters

Potential benefit: If successful, adding docetaxel could lower the chance the cancer grows or spreads and extend the time patients remain controlled on therapy.

How similar studies have performed: Previous trials have shown that adding docetaxel to ADT can improve outcomes and some studies combining ARPIs and chemotherapy have shown promising results, but this specific strategy for patients selected by suboptimal PSA response is being tested directly.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Histologically/cytologically confirmed adenocarcinoma of the prostate
* Metastatic disease by conventional imaging
* PSA of ≥5.0 ng/ml (5.0 ug/L) prior to commencement of ADT
* Receipt of ADT for mCSPC for at least 6 months and no greater than 12 months at time of enrollment.
* Receipt of ARPI (e.g. abiraterone acetate, enzalutamide, apalutamide, or darolutamide) for at least 4 months at time of enrollment
* Potential trial participants should have recovered from clinically significant adverse events of their most recent therapy/intervention prior to enrollment.
* Serum testosterone \<1.7 nmol/L or 50 ng/dL.
* PSA ≥ 0.2 ng/ml (0.2 ug/L) within 14 days of enrollment. If there is any rise in PSA since starting ADT and achieving castrate-level testosterone, PSA must be repeated and must not fulfill ineligibility criteria 4.2.1.
* Candidate for docetaxel chemotherapy
* ECOG Performance Status (PS) 0 to 2.
* Adequate organ and marrow function measured within 14 days prior to enrollment.
* Participant consent must be appropriately obtained in accordance with applicable local and regulatory requirements. Each participant must sign a consent form prior to enrollment in the trial to document their willingness to participate.
* Participants must be accessible for treatment and follow-up. Investigators must assure themselves the participants enrolled on this trial will be available for complete documentation of the treatment, adverse events, and follow-up.
* In accordance with CCTG policy, protocol treatment is to begin within 5 working days of participant enrollment.
* If the participant and the participant's partner are of childbearing potential, they must agree to use medically accepted methods of contraception
* HIV-infected participants on effective anti-retroviral therapy with undetectable viral load within 6 months are eligible for this trial.
* Participant access to all protocol therapies must be confirmed prior to enrollment

Exclusion Criteria:

* Two consecutive rises in PSA since achieving castration on ADT at least 2 weeks apart with at least one PSA ≥5% above the PSA nadir and with at least one PSA having an absolute increase of ≥0.5 ng/ml above the PSA nadir.
* Evidence of radiographic progression or clinical progression since start of ADT.
* Docetaxel criteria:

  * Prior treatment with taxane chemotherapy
  * Grade 2 or worse peripheral neuropathy
  * Severe hypersensitivity to drugs formulated with polysorbate 80
* Patients with known history or current symptoms of cardiac disease, or history of treatment with cardiotoxic agents, should have a clinical risk assessment of cardiac function using the New York Heart Association Functional Classification. To be eligible for this trial, patients should be class II or better.
* Patients with uncontrolled intercurrent illness or any other significant condition(s) that would make this protocol unreasonably hazardous.
* Patients with a prior or concurrent malignancy whose natural history of treatment does not have the potential to interfere with the safety or efficacy assessment of the investigational regimen are eligible for this trial.
* Concurrent treatment with other anti-cancer systemic therapy other than ADT and ARPI.
* Live attenuated vaccination administered within 30 days prior to enrollment/randomization.
* For participants with a history of chronic hepatitis B virus (HBV) infection, the HBV viral load must be undetectable on suppressive therapy, if indicated.
* Participants with a history of hepatitis C virus (HCV) infection must have been treated and cured. For participants with HCV infection who are currently on treatment, they are eligible if they have an undetectable HCV viral load.
* High-grade neuroendocrine prostate cancer or small cell features.

Where this trial is running

Anchorage, Alaska and 339 other locations

+290 more sites — see ClinicalTrials.gov for the full list.

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Prostate CancerPR26Castration sensitive
Last reviewed 2026-06-13 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.