Medical resource utilization of abiraterone acetate plus prednisone added to androgen deprivation therapy in metastatic castration-naive prostate cancer: Results from LATITUDE

Background: Abiraterone acetate plus prednisone (AA+P), when added to androgen deprivation therapy (ADT), demonstrated significant improvements in overall survival and disease progression over dual placebos added to ADT in the LATITUDE clinical trial (NCT01715285). The objective of this study was to assess event-driven medical resource utilization (MRU) of ADT plus AA+P (ADT+AA+P) versus ADT plus dual placebos (ADT+placebos) in LATITUDE.

Methods: Event-driven MRU data from LATITUDE while patients were on treatment were used for analyses. Types of MRU included overnight hospitalizations and length of stay (LOS), emergency room (ER) visits, radiotherapy, surgery, imaging, and specialist and general practitioner (GP) visits. Rates by treatment (per 100 person-years) and rate ratios comparing ADT+AA+P with ADT+placebos were estimated with zero-inflated Poisson regression. The difference in the average hospital LOS between arms was assessed with repeated measures regression analyses. Reasons for hospitalization were explored. Sensitivity analyses were conducted to assess the robustness of the results.

Results: A total of 1199 patients were enrolled in LATITUDE. Significantly lower rates of hospitalization (a 24% reduction), imaging (a 36% reduction), and radiotherapy (a 50% reduction) were observed with ADT+AA+P versus ADT+placebos. There was a nonsignificant trend of lower rates of specialist visits and surgery. The rates of ER and GP visits and the average LOS per hospitalization episode were similar across arms. The most common hospitalization reasons were genitourinary, musculoskeletal, and respiratory tract symptoms/disorders. The results remained consistent in a sensitivity analysis.

Conclusions: Adding AA+P to ADT does not increase MRU and leads to lower rates of hospitalization, imaging, and radiotherapy. This likely reflects the more favorable clinical outcomes with ADT+AA+P therapy.