Evidence for Improved Patient Quality of Life With Prostate Cancer Drug

Abiraterone acetate in combination with prednisone delays pain progression in prostate cancer patients as well as health-related quality of life compared with prednisone alone, according to a new study published in Lancet Oncology.

Abiraterone acetate was first approved by the US Food and Drug Administration (FDA) in patients with metastatic castration-resistant prostate cancer (CRPC) following treatment with the chemotherapy docetaxel in 2011 and subsequently as a first-line treatment for metastatic CRPC in 2012-FDA Expands Label for Abiraterone Acetate (Zytiga) in Metastatic Prostate Cancer.” The majority of patients taking abiraterone initially have asymptomatic or only mildly symptomatic disease.

The current pre-specified analysis is the effect of abiraterone treatment on the quality of life of CRPC patients who were part of the phase III randomized COU-AA-302 study. Asymptomatic and mildly symptomatic patients were randomized 1:1 to receive either abiraterone with prednisone or prednisone alone.

“[The study demonstrates that] it is feasible to measure time to pain progression in a prospective trial enrolling minimally symptomatic patients with cancer, which paves the way for future trials to use a similar measurement approach,” said lead author Ethan Basch, MD, director of the Cancer Outcomes Research Program at the University of North Carolina Lineberger Comprehensive Cancer Center in North Carolina.

Basch and colleagues assessed different quality-of-life criteria throughout the treatment of the 1,088 patients enrolled in the clinical trial. Dr. Basch has been an advocate for patient-centered drug development and including data on quality of life (how a cancer drug actually impacts a patient’s daily life) in cancer clinical trials-“Implementing Patient-Centered Outcomes in Cancer Trials.”

The median follow-up for the current patient-mediated outcomes analysis was 22.2 months.

Treatment with abiraterone plus prednisone resulted in postponement of pain onset by more than 8 months compared with prednisone alone (26.7 months vs 18.4 months, respectively; P = .049). Worsening of quality of life was delayed by more than 4 months in the combination arm compared with the control arm (12.7 months vs 8.3 months; P = .003). The time to pain that interfered with daily activities was also longer in the combination arm compared with the control arm (10.3 months vs 7.4 months; P = .005). The median time to worst pain was also longer in the combination arm (26.7 months) compared with the control arm (19.4 months) but this difference was not significant (P = .109).

“There is prior evidence showing that pain is a major problem for men with advanced prostate cancer, and many men in this situation value treatments that can reduce pain,” said Basch. “Measurement of pain is relevant here and is additionally supported by general quality-of-life measurements to assure that pain isn't improved at the expense of other symptoms or functioning.

The relevant patient-related outcomes for other cancer types may be less clear and requires multi-step and qualitative research and interviews to identify the relevant outcomes, said Basch. The National Cancer Institute, along with oncologists, is currently developing an adverse event reporting system tailored for patient self-reporting called the Patient-Reported Outcomes version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE).

Both symptoms and quality of life should be measured rigorously in all phase III studies including patients with advanced cancers, according to Basch. “Leaving out this type of assessment is an omission and leads to an incomplete picture of the properties of a given product under study.”