Data from Neoadjuvant Cabazitaxel Plus Abiraterone/Leuprolide Acetate in High-Risk Prostate Cancer Patients: ACDC-RP Phase II Trial

AbstractPurpose: Early treatment intensification with neoadjuvant therapy may improve outcomes in high-risk, localized prostate cancer (PCa) patients treated with radical prostatectomy (RP). Our objective was to compare pathologic, oncologic, and safety outcomes of neoadjuvant abiraterone acetate plus leuprolide acetate with or without cabazitaxel prior to RP in localized, high-risk PCa patients. Patients and Methods: This open-label, multicenter, phase II trial randomized men with clinically localized, D’Amico high-risk PCa to neoadjuvant abiraterone acetate (1000mg/day) and leuprolide acetate (22.5mg every three months) with or without cabazitaxel (25mg/m2) prior to RP. The primary outcome was pathologic complete response (pCR) or minimal residual disease (MRD). Secondary outcomes included surgical margins, lymph node involvement, pathologic stage, 12-month biochemical relapse-free survival (BRFS) rates, and safety profile. Results: The per-protocol population consisted of 70 patients (Cabazitaxel arm Arm A: 37, No cabazitaxel arm Arm B: 33). Median patient age and prostate-specific antigen levels were 63.5 years (IQR:58.0-68.0) and 21.9 ng/ml (IQR:14.6-42.8), respectively. pCR/MRD occurred in 16 (43.2%) versus 15 patients (45.5%) in Arms A and B, respectively (p=0.85). pCR occurred in two (5.4%) versus three patients (9.1%) in Arms A and B, respectively (p=0.66). Patients with ≤25% total biopsy cores positive had increased odds of pCR/MRD (p=0.04). Patients with pCR/MRD had superior 12-month BRFS rates (96.0% versus 62.0%, p=0.03). Grade 3+ adverse events occurred in 42.5% and 23.7% of patients in arms A and B, respectively (p=0.078). Conclusion: Neoadjuvant cabazitaxel addition to abiraterone acetate/leuprolide acetate prior to RP did not improve pCR/MRD in clinically localized, high-risk PCa.