Progression free survival in males with metastatic castrate resistant prostate cancer treated with abiraterone acetate or enzalutamide in an academic pharmacist-staffed oncology clinic

Introduction: The use of noninvasive oral oncology agents has increased in the recent decade shifting the prototype for treatments. Treatment strategies for metastatic castrate resistant prostate cancer (mCRPC) have evolved recently with approved oral abiraterone acetate and enzalutamide. Despite the fact that oral agents offer convenience and increased quality of life, they pose financial challenges, unique toxicities, and barriers that could impact progression free survival (PFS). With the initiation of complex regimens and monitoring, pharmacist involvement has become a vital role in cancer patient care in the outpatient setting.

Objectives: The aim of this study was to evaluate if PFS in mCRPC patients who are prescribed abiraterone acetate or enzalutamide through a pharmacist-staffed academic oncology clinic is consistent with PFS found in the literature.

Study Design: Single center, retrospective chart review.

Methods: This study included adult males (>18) with a diagnosis of mCRPC receiving abiraterone acetate or enzalutamide from August 2012 through September 2015. Exclusion criteria included clinical trial and non-metastatic CRPC patients. The primary outcome assessed median time to PFS. Secondary outcomes included number and type of pharmacist interventions and appropriateness of medication refills compared to treatment course. Patients were identified using an electronic medical record report.

Results: This study included 68 adult patients; 34 (50%) of the patients received both therapies while 18 (26%) and 16 (24%) received abiraterone acetate or enzalutamide, respectively. Of the 34 that received both medications, 29 (85%) received abiraterone first and 5 (15%) received enzalutamide first. Outcome results pending further data collection.

Conclusions: Pending final results.