OBJECTIVES: Docetaxel and Cabazitaxel are taxane chemotherapy approved in men with mCRPC after they demonstrated improved survival in first and second line respectively. If recent data suggested similar efficacy, these two taxanes have different safety profile and unit price, raising the question of their administration sequence. A cost-utility analysis comparing two sequences of treatment (Cabazitaxel followed by Docetaxel versus Docetaxel followed by Cabazitaxel) for first-line chemotherapy in metastatic prostate cancer was performed in the French context, using data from the CABADOC randomized trial.

METHODS: The CABADOC study is a randomized trial with a cross-over design. Patients were randomized to receive either Docetaxel 75mg/m²/q3w x 4 followed by Cabazitaxel 25mg/m²/q3w x 4, or the reverse sequence. The economic analysis included a prospective collection of resources consumed (chemotherapy, hospitalizations, transportation, nurses and consultations) and utility data (using the EQ-5D questionnaire administered before cycle 1, cycle 5 and at the end of chemotherapy) alongside the trial. Costs were evaluated from the French collective perspective and horizon time was limited from the randomization date to the end of 2^nd sequence chemotherapy. The ICER was calculated and sensitivity analyses were conducted.

RESULTS: From June 2014 to October 2016, 195 patients (median age of 70 years) were randomized in 17 centers. Patients received 3.8 ± 0.7 and 3.2 ± 1.5 cycles of chemotherapy during the first and the second period, respectively. The sequence Docetaxel-Cabazitaxel appears to be more effective (mean QALY per patient of 0.353 ± 0.025 versus 0.328 ± 0.063) and less expensive (mean cost per patient of 17 350 € ± 2955 versus 17 862 € ± 2320) as compared to the sequence Cabazitaxel-Docetaxel.

CONCLUSIONS: The sequence of treatment with Docetaxel followed by Cabazitaxel appears the optimal one for first line chemotherapy in metastatic prostate cancer from a cost-utility standpoint.

NCT: NCT02044354