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).

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.

Observational, 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.

Of 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.

Second-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.

BMC cancer. 2019 Aug 05*** epublish ***

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

Medical Oncology, Hospital Clínico San Carlos. Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), CIBERONC, C/Profesor Martín Lagos, s/n 28040, Madrid, Spain. ., Medical Oncology, Hospital Universitario Puerta de Hierro-Majadahonda, Madrid, Spain., Medical Oncology, ICO Girona, Hospital Josep Trueta, Girona, Spain., Oncology Department, Maimonides Institute of Biomedical Research (IMIBIC). Reina Sofía Hospital. University of Córdoba, Cordoba, Spain., Medical Oncology, University Hospital La Paz - IdiPAZ, Madrid, Spain., Medical Oncology, Hospital Universitario de León, León, Spain., Medical Oncology, Hospital Universitario de la Ribera, Alcira, Spain., Medical Department, Janssen-Cilag S.A., Madrid, Spain., Medical Oncology, Hospital Universitario Lucus Augusti, Lugo, Spain.