Conditions: Prostate Cancer Metastatic
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 63
Healthy volunteers: no

Brief summary:
Docetaxel and cabazitaxel are cancer chemotherapy agents of the taxane drug class. The purpose of this study is to explore the benefit, for treatment of metastatic castration-resistant prostate cancer (mCRPC), of a regimen in which participants begin treatment with either of these two taxane drugs (docetaxel or cabazitaxel, in combination with prednisone) and are switched to the other taxane drug if prostate-specific antigen (PSA) value does not decrease ≥30% after 4 cycles. As defined in study protocol amendment 3, efficacy results are summarized for all participants combined, irrespective of which agent (docetaxel or cabazitaxel) was administered initially, rather than separately for the two groups based on taxane administered initially. One of the primary outcome measures is percentage of participants with a ≥50% sustained decrease from baseline in PSA at any time during the trial. By providing an opportunity for patients to switch taxane based on early PSA response, there may be a difference in result for this measure versus result in a study where it was not possible to switch. The other primary outcome measures are change from baseline in circulating tumor cells (CTCs) biomarkers percent androgen receptor nuclear localization (%ARNL) and microtubule bundling (MTB).

Detailed description:
* Participants were treated until progressive disease, unacceptable toxicity, death, or participant's refusal of further study treatment. All participants were followed until death or the study cut-off date, whichever came first.
* Study cut-off was 1 month after the last participant last treatment.
* Participants alive at the cut-off date were not followed for overall survival.

Arms:
arm 1: Docetaxel 75 mg/m\^2 intravenous (IV) infusion on Day 1 of Cycle 1 and every 3 weeks (q3w) thereafter, in combination with Prednisone (or Prednisolone) 10 mg orally daily. Participants with \<30% PSA reduction from baseline at the end of Cycle 4 switched to Cabazitaxel 25mg/m\^2 IV infusion on Day 1 of Cycle 5 and q3w thereafter, in combination with Prednisone (or Prednisolone) 10 mg orally daily until disease progression (DP), death, unacceptable toxicity or participant's refusal of further study treatment. Participants with ≥30% PSA reduction from baseline at the end of Cycle 4, continued on the same treatment which they received before switching until DP, death, unacceptable toxicity or participant's refusal of further study treatment. arm 2: Cabazitaxel 25 mg/m\^2 IV infusion on Day 1 of Cycle 1 and q3w thereafter, in combination with Prednisone (or Prednisolone) 10 mg orally daily. Participants with \<30% PSA reduction from baseline at the end of Cycle 4 switched to Docetaxel 75mg/m\^2 IV infusion on Day 1 of Cycle 5 and q3w thereafter, in combination with Prednisone (or Prednisolone) 10 mg orally daily until DP, death, unacceptable toxicity or participant's refusal of further study treatment. Participants with ≥30% PSA reduction from baseline at the end of Cycle 4, continued on the same treatment which they received before switching until DP, death, unacceptable toxicity or participant's refusal of further study treatment.

Interventions: intervention 1: DOCETAXEL (XRP6976) intervention 2: CABAZITAXEL (XRP6258) intervention 3: Prednisone
Intervention descriptions: intervention 1: Pharmaceutical form: Concentrate for solution for infusion Route of administration: Intravenous intervention 2: Pharmaceutical form: Concentrate and solvent for solution for infusion Route of administration: Intravenous intervention 3: Pharmaceutical form: Tablet Route of administration: Oral

Protocol document: