Efficacy and safety of abiraterone acetate plus prednisone vs. cabazitaxel as a subsequent treatment after first-line docetaxel in metastatic castration-resistant prostate cancer: results from a prospective observational study (CAPRO)

Javier Puente,Jacobo Rodrigo Muñoz Del Toro,Alvaro Pinto,José Miguel Cuevas Sanz,Núria Sala-Gonzalez,Ángel Rodríguez,Sergio Vázquez,Aranzazu González-Del-Alba,Ángela García García-Porrero,Eduardo Useros Rodríguez,María José Méndez-Vidal

doi:10.1186/s12885-019-5974-9

Abstract

BackgroundTo describe the patterns of second-line treatment of patients with metastatic castration-resistant prostate cancer (mCRPC) after docetaxel treatment in a Spanish population, to identify the factors associated with those patterns, and to compare the efficacy and safety of the treatments most frequently administered.MethodsObservational, prospective study conducted in patients with histologically or cytologically confirmed prostate adenocarcinoma; documented metastatic castration-resistant disease; progression after first-line, docetaxel-based chemotherapy with or without other agents.ResultsOf the 150 patients recruited into the study, 100 patients were prescribed abiraterone acetate plus prednisone (AAP), 44 patients received cabazitaxel plus prednisone (CP), and 6 patients received other treatments. Age (odds ratio [OR] 1.06, 95% [confidence interval] CI 1.01 to 1.11) and not elevated lactate dehydrogenase (LDH) levels (OR 0.33, 95% CI 0.14 to 0.76) were independently associated with the administration of AAP. Treatment with AAP was associated with significantly longer clinical/radiographic progression-free survival (hazard ratio [HR] 0.57, 95% CI 0.38 to 0.85) and overall survival (OS; HR 0.40, 95% CI 0.21 to 0.76) compared to CP, while no significant differences between the treatments were found regarding biochemical progression-free survival (PFS; HR 0.78 [95% CI 0.49 to 1.24]). However, in a post-hoc Cox regression analysis adjusted for potential confounders there were not differences between AAP and CP in any of the time-to-event outcomes, including overall survival. We observed no new safety signals related to either regimen.ConclusionSecond-line AAP for patients with mCRPC is the most common treatment strategy after progression with a docetaxel-based regimen. When controlling for potential confounders, patients receiving this treatment showed no differences in PFS and OS in comparison to those receiving CP, although these latter results should be confirmed in randomized controlled trials.

Highlights

To describe the patterns of second-line treatment of patients with metastatic castration-resistant prostate cancer after docetaxel treatment in a Spanish population, to identify the factors associated with those patterns, and to compare the efficacy and safety of the treatments most frequently administered
A limited number of retrospective studies have compared the different sequences of androgen receptor-targeted therapies (ARAT) [11, 12], and no evidence is available from sequencing studies comparing ARAT vs chemotherapy prospectively
Compared with patients treated with abiraterone acetate plus prednisone, patients who received cabazitaxel plus prednisone exhibited higher prostate-specific antigen (PSA) levels and Gleason scores, higher Eastern Cooperative Oncology Group (ECOG) performance status, and a greater number of bone metastases

Summary

Introduction

To describe the patterns of second-line treatment of patients with metastatic castration-resistant prostate cancer (mCRPC) after docetaxel treatment in a Spanish population, to identify the factors associated with those patterns, and to compare the efficacy and safety of the treatments most frequently administered. In patients with metastatic castration-resistant prostate cancer (mCRPC), docetaxel in combination with prednisone was the first regimen to demonstrate an increase in survival [3] and became the standard of care as chemotherapy. Several agents have been introduced for the treatment of mCRPC, making the selection of treatment more complex [4]. Among these agents, abiraterone acetate plus prednisone, enzalutamide, sipuleucel-T, radium-223 and second-line chemotherapy with cabazitaxel have demonstrated a survival benefit in patients who progressed after docetaxel therapy [5], retreatment with docetaxel represents another therapeutic option [6]. A limited number of retrospective studies have compared the different sequences of androgen receptor-targeted therapies (ARAT) [11, 12], and no evidence is available from sequencing studies comparing ARAT vs chemotherapy prospectively

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