898PD - Updated Survival, Quality of Life (QOL), and Safety Data of Radium-223 Chloride (RA-223) in Patients with Castration-Resistant Prostate Cancer (CRPC) with Bone Metastases from the Phase 3 Double-Blind, Randomized, Multinational Study (ALSYMPCA)

Abstract

ABSTRACT Introduction Ra-223 is a first-in-class alpha-emitter pharmaceutical that targets bone metastases with high-energy, very short range ( Methods Eligible pts previously received or refused docetaxel, or were docetaxel ineligible, and were randomized 2:1 to receive Ra-223 (50 kBq/kg IV) or Pbo every 4 weeks x 6. After the IA, an updated analysis of all enrolled pts prior to crossover assessed effects of Ra-223 on the primary (OS, using a stratified log-rank test) and secondary (eg, skeletal-related events [SREs], QOL, and safety) endpoints. QOL was assessed with the Functional Assessment of Cancer Therapy—Prostate (FACT-P) and EuroQoL (EQ-5D) instruments. Results The table shows the updated analysis data for 921 pts (Ra-223, n = 614; Pbo, n = 307). Median OS benefit for Ra-223 was 3.6 mos (HR 0.695). Time to first SRE was 6 mos longer with Ra-223. At week 16, Ra-223 pts reported significantly greater well-being (physical, emotional, functional, prostate cancer score, and total score) (FACT-P) and significantly better QOL (EQ-5D) compared to Pbo pts. The incidence of myelosuppression with Ra-223 was low: 2.2% grade 3/4 neutropenia; 6.3% grade 3/4 thrombocytopenia. Parameter Ra-223 + BSC (n = 614) Placebo + BSC (n = 307) P value Hazard ratio (95% CI) Median overall survival, mos 14.9 11.3 .00007 0.695 (0.581, 0.832) Median time to first SRE, mos 15.6 9.8 .00037 0.658 (0.522, 0.830) FACT-P * Physical well-being -0.93 -1.65 0.047 Emotional well-being -0.12 -1.27 Functional well-being -1.15 -2.23 0.011 Prostate cancer score -0.10 -1.74 0.012 Trial outcome index score -2.14 -5.16 0.011 FACT-P total score -2.53 -6.88 0.006 EQ-5D * Single index utility -0.0181 -0.0952 0.003 * Mean change from baseline at week 16. Conclusions The ALSYMPCA updated analysis substantiates that Ra-223 is an effective therapy that significantly improves OS and time to first SRE, with a highly favorable safety profile, in CRPC pts with bone mets. Ra-223 showed significantly better preservation of QOL, with improved functioning and well-being, compared to Pbo. Disclosure C. Parker: C. Parker has served in a consultant or advisory role for Algeta ASA (uncompensated) and Bayer. S. Nilsson: S. Nilsson has served in a consultant or advisory role for Algeta ASA. N. Vogelzang: N. Vogelzang has served in a consultant or advisory role for and has received grant/research support from Algeta ASA and Bayer. K. Staudacher: K. Staudacher is employed by and has an ownership interest in Algeta ASA. R. van Gool: R. Van Gool is employed by and has an ownership interest in Bayer. A.O. Sartor: O. Sartor has served in consultant or advisory roles for Algeta ASA and Bayer. All other authors have declared no conflicts of interest.