Enzalutamida vs abiraterona en el manejo del cáncer de próstata resistente a la castración: comparación indirecta de tratamientos / Enzalutamide vs Abiraterone in Castration Resistant Prostate Cancer: Indirect Comparison of Treatments

RESUMEN

Introducción Actualmente se dispone de nuevos medicamentos que aumentan la supervivencia en pacientes con cáncer de próstata resistente a la castración. Entre ellos están la Enzalutamida y la Abiraterona. Actualmente no se dispone de experimentos clínicos comparativos. Este estudio tiene como objetivo identificar las diferencias entre la Enzalutamida y la Abiraterona, a través de un modelo de comparación indirecta de tratamientos en pacientes con cáncer de próstata metastásico resistente a la castración. Materiales y Métodos Se realizó una búsqueda sistemática de la literatura incluyendo ensayos clínicos aleatorizados, en pacientes con cáncer de próstata resistente a la castración que recibieron manejo con Enzalutamida y Abiraterona; tomando como desenlace la supervivencia global y libre de progresión radiológica. Se realizó una comparación de la información y un modelo de Bucher para datos indirectos. Resultados Se incluyeron 2 experimentos clínicos fase 3 de manejo pre quimioterapia y 2 en manejo postquimioterapia. Se involucraron 1418 pacientes en el grupo de estudio prequimioterapia y 1596 en el grupo de estudio postquimioterapia. Al comparar la Enzalutamida versus Abiraterona, no se encontraron diferencias estadísticamente significativas. En la prequimioterapia, la supervivencia global con HR 0,87 (95%IC 0,70­1,09) (p = 0,94), supervivencia libre de progresion radiológica con HR 0,35 (95% IC 0,28­0,44) (p = 0,81) y en postquimioterapia, supervivencia global con HR 0,85 (95% IC 0,67­1,06) (p = 0,82) y supervivencia libre de progresión radiológica con HR 0,60 (95% IC 0,49­0,74) (p = 0,82). Conclusiones No existe una diferencia estadísticamente significativa en la supervivencia global y libre de progresión radiológica entre los dos medicamentos.

ABSTRACT

Introduction and Objective From translational medicine, development of new drugs that increase survival in patients with castration-resistant prostate cancer is obtained. Among these are abiraterone and Enzalutamide, with different mechanisms of action, but with an aplication in the same clinical stage. Currently, there are no comparative clinical trials between these drugs. This study aims to identify the differences between Enzalutamide and Abiraterone through a model of indirect comparison of treatment in patients with castration resistant prostate cancer in pre and post chemotherapy stages. Materials and Methods A systematic search of the literature was conducted including randomized phase 3 clinical trials in patients with castration-resistant prostate cancer receiving management with Enzalutamide and Abiraterone compared with placebo or corticoid in pre and post chemotherapy stages, taking as outcome overall survival and radiologic progression-free survival. In addition to the demographic analysis, a comparison of information and a modified model of Bucher for indirect data was performed, with the statistical program Stata version 12 and ICT CADTH program. Results 2 Phase III clinical trials were included in the pre chemotherapy stage and 2 in postchemotherapy stage. 1418 patients in the study group prechemotherapy and 1596 in the post- chemotherapy group study were involved. Control groups involved 1387 and 796 cases respectively. When comparing Enzalutamide vs Abiraterone in the pre chemotherapy group, no statistically significant difference was noted in overall survival HR 0.87 (95% CI 0.70 - 1.09) (p = 0.94) and radiologic progression-free survival HR 0.35 (95 % CI 0.28 to 0.44) (p = 0.81). In post-chemotherapy group, overall survival HR 0.85 (95 % CI 0.67 - 1.06) (p = 0.82) and radiologic progression-free survival HR 0.60 (95 % CI 0.49 to 0.74 ) (p = 0.82) no statistically significant difference was noted. Conclusions There is no statistically significant difference in overall survival and radiologic progression-free survival between the two drugs. The indirect comparison of treatments offers a valid alternative in the absence of direct comparative clinical experiences.