The addition of abiraterone acetate (Zytiga) to androgen-deprivation therapy (ADT) did not increase medical resource utilization in patients with metastatic castration-naïve prostate cancer who participated in the multinational LATITUDE clinical trial.
The use of some resources, such as overnight hospitalization and imaging, declined in patients who were randomized to abiraterone plus ADT compared with those who received placebo plus ADT, said Tracy Li, PhD, Director of Global Market Access and Health Economics, Janssen, who presented the results at the 2018 Genitourinary Cancers Symposium.
The current treatment landscape for patients with castration-naïve prostate cancer is dynamic, although ADT remains a cornerstone therapy, Dr Li said. In the LATITUDE study, abiraterone added to ADT significantly improved overall survival and reduced disease progression compared with placebo plus ADT.
“To fully understand the economic consequences of adopting abiraterone plus ADT for use in metastatic castration-naïve prostate cancer, an understanding of the medical resource use implications associated with treatment is required,” she said.
The objective of the current study was to compare event-driven medical resource utilization among the 1199 patients enrolled in LATITUDE. Specifically, medical resources other than those mandated by the study protocol were assessed from the first to the last dose of the study medication.
“We wanted to find out what it meant to the healthcare system when you have an effective treatment for a disease, and you improve the clinical aspects and slow down disease progression,” Dr Li said.
“Improving overall survival and radiographic progression-free survival, slowing down disease progression, and delaying the use of chemotherapy meant a decrease in overnight hospitalization, use of radiotherapy and surgery, and the need for imaging, with trends toward fewer visits to oncologists and urologists,” she added.
The proportion of patients with non–protocol-mandated medical resource utilization was 78% for hospitalizations, 81% for imaging, 82% for general practitioner visits, 87% for specialist visits, and 97% for radiotherapy.
The rates of hospitalization in the 2 study arms were 52.71 per 100 person-years in the abiraterone plus ADT arm compared with 69.47 per 100 person-years in the placebo plus ADT arm, amounting to a 24% reduction with the addition of abiraterone to ADT.
The most common reasons for hospitalization were bladder or urethral symptoms (9%), limb fractures or dislocations (6%), spinal cord or nerve root disorders (5%), urinary tract infections (5%), lower respiratory tract or lung infections (4%), febrile disorders (4%), central nervous system hemorrhage or cerebrovascular accident (4%), musculoskeletal or connective tissue pain and discomfort (4%), and bronchospasm or obstruction (4%).
However, the use of imaging outside that mandated by protocol was significantly lower in the abiraterone arm compared with the placebo arm (rate ratio, 0.64; 95% confidence interval [CI], 0.49-0.84), and the use of radiotherapy was significantly lower in the abiraterone arm than in the placebo arm (rate ratio, 0.50; 95% CI, 0.25-1.00).
The rates for specialist visits, surgery, emergency department visits, and general practitioner visits were not significantly different between the 2 arms. The rate of visits to a general practitioner trended toward an increase in the abiraterone arm.
“Visits to the GP [general practitioner] are a mixed bag, because those visits can be for a variety of reasons beyond prostate cancer,” Dr Li observed. “They may not be related to treatment.”
Because LATITUDE was a multinational study, resource utilization rates might have varied by region or country, because of different standards of care for patients, the researchers noted.