Introduction: Radium-223 (Ra-223) significantly improved overall survival (OS), compared with placebo, in the phase 3 randomized trial ALSYMPCA, leading to approval of treatment of adult patients with metastatic castration-resistant prostate cancer (mCRPC), symptomatic bone metastases and no known visceral metastases. No local study has been conducted yet to assess sequencing and use of Ra-223 in mCRPC patients within daily clinical practice in Belgium.
Methods: BELFIGO is an observational retrospective chart review of 164 mCRPC patients treated with Ra-223 between 22/12/2014 and 01/06/2017 in 11 Belgian centers.
The proportions of patients receiving 1-4 and 5-6 injections of Ra-223 were determined and patient characteristics potentially associated with these subgroups were explored. The Kaplan-Meier method was used to describe OS in these 2 subgroups. Sequencing of life-prolonging systemic anti-cancer therapies pre- and post-Ra-223 were reported. Finally, the effectiveness of Ra-223 in clinical practice was described as occurrence and time to progression, occurrence and frequency of SSE-related hospitalizations, reason for early discontinuation and occurrence of blood transfusions.
Results: 31% (n=51) of patients received 1-4 inj. vs. 69% (n=113) who completed 5-6 inj. of Ra-223. Main reasons for early discontinuation of treatment were radiographic progression (n=21), symptomatic progression (n=14), death (n=7) or hematological lab abnormalities (n=6). 10% of patients (n=17) had an SSE-related hospitalization in the 12-months follow-up period and 7% (n=12) received a blood transfusion during treatment.
Median OS was 23.9 months for patients having received 5-6 inj. (727 days, 95% CI:535-906 days) and 7.0 months for patients having received 1-4 inj. (213 days, 95% CI:162-298 days). More than 70% of patients (n=111/155) were known to receive at least 1 treatment line after Ra-223, mainly enzalutamide (33%), docetaxel (30%) or abiraterone (27%).
Conclusion: This Belgian retrospective chart review confirmed that Ra-223 is an effective treatment option with a median OS of 23.9 months in patients receiving 5-6 inj.. It also shows that the use of Ra-223 does not preclude the use of subsequent lines of treatment. Furthermore, these real-world data confirm the low number of SSE-related hospitalizations and blood transfusions observed in ALSYMPCA.
