Effect of radium-223 dichloride (Ra-223) on hospitalisation: An analysis from the phase 3 randomised Alpharadin in Symptomatic Prostate Cancer Patients (ALSYMPCA) trial

- Symptomatic skeletal events (SSEs) are associated with increased hospitalisations.
- Radium-223 reduces SSE risk in metastatic castration-resistant prostate cancer.
- There were significantly fewer hospitalisation events with radium-223 versus placebo.
- Radium-223 reduces hospitalisation days overall, and before first SSE and after SSE.
- Radium-223 may contribute to reduced medical resource use by delaying time to SSE.

Symptomatic skeletal events (SSEs) commonly occur in patients with bone metastases, often leading to hospitalisations and decreased quality-of-life. In the ALSYMPCA trial, radium-223 significantly improved overall survival (hazard ratio 0.70, 95% confidence interval [CI] 0.58-0.83, P < 0.001) and prolonged time to first SSE (hazard ratio 0.66, 95% CI 0.52-0.83, P = 0.00037) and subsequent SSE (hazard ratio 0.65, 95% CI 0.51-0.83, P = 0.00039) versus placebo in patients with castration-resistant prostate cancer with symptomatic bone metastases and no known visceral metastases. Health care resource use (HCRU), including hospitalisation events and days, were prospectively collected in ALSYMPCA. We assessed health care resource use for the first 12 months post-randomisation. Significantly fewer radium-223 (218/589; 37.0%) versus placebo patients (133/292; 45.5%) had at least one hospitalisation event (P = 0.016). However, mean number of hospitalisation events per patient was similar (radium-223 0.69 versus placebo 0.79, P = 0.226), likely due to the significantly longer follow-up time for radium-223 (7.82 months versus 6.92 months for placebo; P < 0.001). There were significantly fewer hospitalisation days per patient for radium-223 (4.44 versus 6.68, respectively, P = 0.004). The reduction in hospitalisation days with radium-223 was observed both before first SSE (2.35 days versus 3.36 days, respectively) and after SSE (7.74 days versus 9.19 days, respectively). Our data suggest that this reduced hospital days along with the survival benefit and reduction in time to SSEs with radium-223 treatment may contribute to improvements in health-related quality-of-life in patients with castration-resistant prostate cancer with symptomatic bone metastases (ALSYMPCA ClinicalTrials.gov number, NCT00699751.).