Cost of preventing an event (COPE) of enzalutamide versus abiraterone plus prednisone in men with metastatic castration-resistant prostate cancer under the Brazilian private health care system perspective

Abstract

Introduction: Metastatic castration-resistant prostate cancer (mCRPC) is defined as a continuous proliferative cancer. With the advancement of new technologies, new treatments were developed: enzalutamide (ENZ) and abiraterone acetate plus prednisone (AA+P). This study examined the cost of preventing an event (COPE) with ENZ and AA+P in the treatment of mCRPC after chemotherapy, from the perspective of the Supplementary Health System, considering the clinical outcomes overall survival (OS) and radiographic progression-free survival (rPFS). Methods: A cost analysis was performed on post-docetaxel pivotal studies for ENZ and AA+P, in order to calculate the COPE. For that two parameters were required: annual treatment cost (ATC) and number needed to treat (NNT). NNT is the inverse of the Absolute Risk Reduction (ARR). COPE is the ATC multiplied by the NNT. Results: The ATC results indicated a BRL1,006 (ENZ: BRL73,799 vs AA+P: BRL74,804) saving per patient treated with ENZ compared to AA+P. NNT, in 12 months, was: NNTOS/ENZ=7.14; NNTrPFS/ENZ=5.00; NNTOS/AA+P=8.33 and NNTrPFS/AA+P=8.33. Thus, the COPE calculated was: COPEOS/ENZ=BRL527,691; COPErPFS/ENZ=BRL369,384; COPEOS/AA+P=BRL623,368 and COPEsPFS/AA+P=BRL623,368. The results show an annual difference of BRL95,677 and BRL253,984, representing an increase in annual costs ranging from 18.13% to 68.76%, depending on the considered outcome. Conclusion: The results indicated that ENZ when compared to AA+P provides a lower COPE (COPEENZ is lower than COPEAA+P for both outcomes analyzed: OS and rPFS).