Efficacy and safety in older patients (pts) with metastatic castration-resistant prostate cancer (mCRPC) receiving cabazitaxel (CBZ) versus abiraterone (ABI) or enzalutamide (ENZ) in the CARD study.

5559 Background: In the CARD (NCT02485691) study, radiographic PFS (rPFS), PFS and OS were significantly improved with CBZ vs. androgen-signaling-targeted agents (ARTA; ABI or ENZ) in pts with mCRPC who had received docetaxel (DOC) and progressed within 12 months (mo) on an alternative ARTA. This analysis evaluated the impact of age (< 70 vs. ≥ 70 years) on the efficacy and safety of CBZ and ARTAs in CARD. Methods: 255 pts with mCRPC were randomized 1:1 to CBZ (25 mg/m2 IV Q3W + prednisone [P] + G-CSF) vs. ABI (1000 mg PO + P) or ENZ (160 mg PO) until disease progression, unacceptable toxicity or pt request. Pts were eligible if they had received ≥ 3 cycles of DOC and progressed ≤ 12 mo on the previous alternative ARTA. Primary endpoint was rPFS. Subgroup analysis of older (≥ 70 years; n = 135) and younger (< 70 years; n = 120) pts was pre-specified for rPFS; others were post hoc. Results: rPFS was significantly improved vs. ARTA in both older (median 8.2 vs. 4.5 mo; HR 0.58; 95% CI 0.38–0.89) and younger pts (median 7.4 vs. 3.2 mo; HR 0.47; 95% CI 0.30–0.74). Median OS for CBZ vs. ARTA was 13.9 vs. 9.4 mo (HR 0.66; 95% CI 0.41–1.06) in older pts and 13.6 vs. 11.8 mo (HR 0.66; 95% CI 0.41–1.08) in younger pts. PFS, tumor, PSA and pain responses also favored CBZ, regardless of age. Grade ≥ 3 adverse events (AEs) occurred in 57.8% vs. 49.3% of older pts receiving CBZ vs. ARTA and 48.4% vs. 42.1% in younger pts. AEs leading to death were more frequent with ARTA, mainly due to disease progression. Conclusions: CBZ had improved efficacy outcomes vs. ARTA in pts with mCRPC previously treated with DOC and the alternative ARTA, regardless of age. Grade ≥ 3 cardiac AEs were more frequent in older pts treated with ARTA. A higher rate of AEs was reported in older vs. younger pts, for ARTA and CBZ. CBZ and ARTA had different safety profiles in older compared with younger pts. Clinical trial information: NCT02485691 . Funding: Sanofi. [Table: see text]