Résumé
Abstract only 152 Background: Chemotherapy with docetaxel-prednisone (DP) is one of the standard treatment of castration-resistant metastatic prostate cancer (CRMPC). However little is known about feasibility of DP in frail elderly patients seen in daily practice. Methods: Randomized phase II study evaluating prospectively the feasibility of DP administered either q3w (Arm A: 60 mg/m² cycle one then 70 mg/m²) or weekly (Arm B: 35 mg/m² D1 D8 q3w) in patients age 75 or older, assessed through comprehensive geriatric assessment (CGA) and classified according to the International Society of Geriatric Oncology (SIOG) as vulnerable (SIOG group 2) or frail (SIOG group 3). Failure was defined as: (1) stop or delay of chemotherapy more than 2 weeks, (2) need for dose reduction more than 25%, (3) febrile neutropenia or NCI CTC grade 3 non-haematological toxicity (excluding alopecia), and (4) decrease of activities of daily living (ADL) scoring two or more points. The study was based on a Simon’s optimum two-stage design for each group (α = 5%, 1-β = 90 %, p0 = 0.70 and p1 = 0.90). An interim analysis was planned after enrolment of 15 patients per arm, with continuation of the program if at least 12 patients met the feasibility criteria. Results: From December 2010 to August 2012, 21 centers have included 66 CRMPC patients, 45 and 21 in SIOG groups 2 and 3 respectively, based on investigators evaluation. The planned interim analysis primary endpoint is based on group allocation by a steering committee (per-protocol [PP] population). The enrolment in group 3 was prematurely closed on October 2012 after inclusion of 19 PP patients (Arm A/B, n=9/10) on recommendation of a safety committee due to an excess of toxic deaths. In this group, only four patients completed six cycles of DP in each arm. In group 2, the planned interim analysis was performed after inclusion of 30 PP patients (Arm A/B n=15/15): 11 and 10 patients in Arm A and B did not meet the predefined criteria for feasibility (73.3%; 95%CI=[44.9; 92.2] and 66.6%; 95%CI=[38.4; 88.2], respectively, and only nine and seven respectively completed six cycles of DP. Conclusions: Chemotherapy with DP given q3w or weekly is not feasible in CRMPC patients age 75 and older classified in SIOG group 2 and 3, according to our study criteria. Patients age 75 and older shouldn’t be offered DP without a CGA. Clinical trial information: NCT01254513.