Abiraterone + ADT: No rise in resource use

San Francisco-Adding abiraterone acetate (ZYTIGA) to androgen deprivation therapy (ADT) for the management of patients with metastatic castration-naïve prostate cancer does not increase medical resource utilization.

Using data from the phase III double-blind placebo-controlled multinational LATITUDE study, researchers led by Tracy Li, PhD, documented significantly lower rates of overnight hospitalization, imaging studies, and radiotherapy for the men randomized to abiraterone compared with placebo. The findings were presented at the Genitourinary Cancers Symposium in San Francisco.

Abiraterone added to ADT in LATITUDE significantly improved overall survival and disease progression compared with placebo and ADT. The economic consequences of adopting abiraterone plus ADT in the 1,199 patients enrolled in LATITUDE were explored by examining event-driven medical resource utilization of study participants. Specifically, medical resources other than those mandated by the study protocol from the first dose of study medication to the last dose were assessed.

“When you have an effective treatment for a disease and you improve the clinical aspects and slow down disease progression, what does that mean to the health care system?” said Dr. Li, director of Global Market Access at Janssen Global Services, Raritan, NJ. “We looked at that question. 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.”

The rates of non-protocol-mandated medical resource utilization were 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 two arms were 52.71 per 100 person-years in the abiraterone/ADT arm compared with 69.47 per 100 person-years in the placebo/ADT arm, representing a 24% reduction for abiraterone/ADT. The most common reasons for hospitalization were bladder/urethral symptoms (9% frequency), limb fractures/dislocations (6%), spinal cord and nerve root disorders (5%), urinary tract infections (5%), lower respiratory tract and lung infections (4%), febrile disorders (4%), central nervous system hemorrhage and cerebrobascular accident (4%), musculoskeletal/connective tissue pain and discomfort (4%), and bronchospasm and obstruction (4%).

Next:Average LOS not significantly differentAverage LOS not significantly different

The average length of stay per hospitalization was not significantly different between the two arms-6.9 days for the abiraterone/ADT arm versus 7.0 days for the placebo/ADT arm.

The use of imaging outside that mandated by protocol was significantly lower in the abiraterone/ADT arm compared with the placebo/ADT arm (rate ratio: 0.64, 95% CI: 0.49-0.84), and the use of radiotherapy was 50% lower in the abiraterone/ADT arm.

Rates for specialist visits, surgery emergency room visits, and general practitioner visits were not significantly different between arms.

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“Visits to the general practitioner are a mixed bag because those visits can be for a variety of reasons beyond prostate cancer,” she said. “They may not be related to treatment.”

The investigators noted that because LATITUDE was a multinational study, the rates of resource use may have varied by region or country due to different standards of care for patients. In addition, clinical trial data may not be generalizable to real-world practice.

Dr. Li has stock and other ownership interests in Johnson & Johnson. Several of Dr. Li’s co-authors have disclosures related to Janssen and/or Johnson & Johnson and/or other pharmaceutical companies.