ABSTRACT
OBJECTIVES: Abiraterone and enzalutamide are two oral novel androgen receptor axis-targeted agents approved for the treatment of castration-resistant prostate cancer (mCRPC). Despite the availability of multiple treatments, there is a need to improve the knowledge and management of these drugs in the real-world setting, especially in patient groups under-represented in clinical trials. Our aim was to review the outcome of patients with chemotherapy-naïve mCRPC treated with abiraterone or enzalutamide in routine clinical practice in order to identify factors that are predictive for response. METHODS: This observational retrospective study was performed in a Spanish tertiary hospital and included men with chemotherapy-naïve mCPRC who started treatment with abiraterone or enzalutamide between September 2012 and November 2018. The study end date was 30 October 2020. RESULTS: Ninety patients with mCRPC were included, 57 with abiraterone and 33 with enzalutamide. Median overall survival (OS) was 26.87 months (95% CI 19.68 to 34.05), with no difference found between the two treatment groups. Nine variables were related to increased OS in the univariate analysis: Eastern Cooperative Oncology Group (ECOG) performance status (0-1 vs 2), pain (need of opioids for cancer pain), visceral disease, ≥3 bone lesions, exclusively lymph node metastases, baseline prostate specific antigen (PSA) (<50 vs ≥50 ng/dL and <20 vs ≥20 ng/dL), haemoglobin (<12 vs ≥12 g/dL) and alkaline phosphatase (≤116 vs >116 IU/L). A PSA response >50% was observed in 65 patients (76.5%). In the multivariate analysis, ECOG performance status, pain, visceral disease and alkaline phosphatase provided independent prognostic information. Median OS by Kaplan-Meier analysis was significantly longer for patients with a PSA response (32.1 vs 17.9 months; HR 0.46, 95% CI 0.27 to 0.78; p=0.003). CONCLUSIONS: This study assessed the efficacy of abiraterone and enzalutamide in a real-world setting, including patients under-represented in pivotal studies. Some clinical factors were correlated with improved OS in chemotherapy-naïve men with mCPRC treated with these drugs.
Subject(s)
Prostatic Neoplasms, Castration-Resistant , Male , Humans , Prostatic Neoplasms, Castration-Resistant/drug therapy , Prostatic Neoplasms, Castration-Resistant/pathology , Prostate-Specific Antigen/therapeutic use , Retrospective Studies , Alkaline Phosphatase/therapeutic useABSTRACT
OBJECTIVE: Given that hypoalbuminemia tends to result in higher free fraction concentrations of valproic acid, different methods have been developed to determine the latter in patients with this condition. The aim of this study is to assess the reliability of these methods and, if necessary, design a new estimation method. METHOD: A retrospective analysis was carried out by the Pharmacy Department of Severo Ochoa University Hospital of admitted patients with at least one trough concentration of valproic acid between October 2017 and February 2019. The estimation methods used were those developed by Kodama, Hermida, Doré, as well as a new method proposed in the study. A total of 17 serum valproic acid concentrations were used to determine the free fraction of valproic acid with each method; the values obtained were compared with the results obtained following laboratory determinations. Accuracy and precision were calculated using mean error and root mean square error, respectively. RESULTS: The comparison between observed and predicted free valproic acid values using the methods under investigation showed that the method proposed in this study provides the highest reliability as it presents the highest accuracy and precision. The worst results were those obtained using the Kodama method, which does not consider albuminemia, an essential variable that determines the concentration, therapeutic effect and toxicity of valproic acid. CONCLUSIONS: Given that the method proposed in this study proved to be superior to the other methods analyzed, we believe it can be reliably used to estimate free valproic acid levels in patients with hypoalbuminemia.
OBJETIVO: La fracción de ácido valproico libre aumenta en pacientes con hipoalbuminemia. Se han publicado diferentes métodos para su estimación.El objetivo de este estudio es valorar la fiabilidad de dichos métodos en nuestra población y proponer un nuevo método de estimación.Método: Análisis retrospectivo realizado por el Servicio de Farmacia del Hospital Universitario Severo Ochoa en pacientes ingresados entre octubre de 2017 y febrero de 2019 con al menos una concentración valle de ácido valproico. Los métodos de estimación empleados fueron los de Kodama, Hermida, Doré y un nuevo método propuesto, diseñado por García. A partir de 17 mediciones de ácido valproico se comparó el ácido valproico libre estimado con cada método y el obtenido en el laboratorio. Se calcularon la exactitud y la precisión mediante el error medio y el error cuadrático medio, respectivamente. RESULTADOS: La comparación entre los valores observados y predichos de ácido valproico libre por los distintos métodos evaluados pone de manifiesto que el de mayor fiabilidad es el diseñado por García, al presentar la mejor exactitud y precisión. Los peores resultados son los del método Kodama, al no considerar la albuminemia, variable fundamental que condiciona la concentración, el efecto terapéutico y la toxicidad de este fármaco. CONCLUSIONES: El método diseñado por García ha demostrado ser mejor que otros métodos, por lo que puede ser propuesto para estimar con fiabilidad el ácido valproico libre en pacientes con hipoalbuminemia, aunque se precisa aplicarlo en un mayor número de pacientes para confirmar su utilidad.
Subject(s)
Valproic Acid , Data Collection , Humans , Reproducibility of Results , Retrospective Studies , Valproic Acid/therapeutic useABSTRACT
Objetivo: La fracción de ácido valproico libre aumenta en pacientescon hipoalbuminemia. Se han publicado diferentes métodos para su estimación.El objetivo de este estudio es valorar la fiabilidad de dichosmétodos en nuestra población y proponer un nuevo método de estimación.Método: Análisis retrospectivo realizado por el Servicio de Farmaciadel Hospital Universitario Severo Ochoa en pacientes ingresados entreoctubre de 2017 y febrero de 2019 con al menos una concentraciónvalle de ácido valproico. Los métodos de estimación empleados fueronlos de Kodama, Hermida, Doré y un nuevo método propuesto, diseñadopor García. A partir de 17 mediciones de ácido valproico se comparóel ácido valproico libre estimado con cada método y el obtenido en ellaboratorio. Se calcularon la exactitud y la precisión mediante el errormedio y el error cuadrático medio, respectivamente.Resultados: La comparación entre los valores observados y predichosde ácido valproico libre por los distintos métodos evaluados pone demanifiesto que el de mayor fiabilidad es el diseñado por García, alpresentar la mejor exactitud y precisión. Los peores resultados son los delmétodo Kodama, al no considerar la albuminemia, variable fundamental que condiciona la concentración, el efecto terapéutico y la toxicidad deeste fármaco.Conclusiones: El método diseñado por García ha demostrado ser mejorque otros métodos, por lo que puede ser propuesto para estimar con fiabilidadel ácido valproico libre en pacientes con hipoalbuminemia, aunque seprecisa aplicarlo en un mayor número de pacientes para confirmar su utilidad
Objective: Given that hypoalbuminemia tends to result in higher freefraction concentrations of valproic acid, different methods have beendeveloped to determine the latter in patients with this condition. The aimof this study is to assess the reliability of these methods and, if necessary,design a new estimation method.Method: A retrospective analysis was carried out by the PharmacyDepartment of Severo Ochoa University Hospital of admitted patientswith at least one trough concentration of valproic acid between October2017 and February 2019. The estimation methods used were those developedby Kodama, Hermida, Doré, as well as a new method proposed inthe study. A total of 17 serum valproic acid concentrations were used todetermine the free fraction of valproic acid with each method; the valuesobtained were compared with the results obtained following laboratorydeterminations. Accuracy and precision were calculated using mean errorand root mean square error, respectively.Results: The comparison between observed and predicted free valproicacid values using the methods under investigation showed that the methodproposed in this study provides the highest reliability as it presents the highestaccuracy and precision. The worst results were those obtained using the Kodama method, which does not consider albuminemia, an essentialvariable that determines the concentration, therapeutic effect and toxicityof valproic acid.Conclusions: Given that the method proposed in this study proved to besuperior to the other methods analyzed, we believe it can be reliably usedto estimate free valproic acid levels in patients with hypoalbuminemia.
