PURPOSE:To investigate the dose-response relationship and pain-relieving effect of radium-223, a highly bone-targeted alpha-pharmaceutical.
METHODS: One hundred patients with castration-resistant prostate cancer (CRPC) and painful bone metastases were randomized to a single intravenous dose of 5, 25, 50 or 100kBq/kg radium-223. The primary end-point was pain index (visual analogue scale [VAS] and analgesic use), also used to classify patients as responders or non-responders.
RESULTS: A significant dose response for pain index was seen at week 2 (P=.035). At week 8 there were 40%, 63%, 56% and 71% pain responders (reduced pain and stable analgesic consumption) in the 5, 25, 50 and 100kBq/kg groups, respectively. On the daily VAS, at week 8, pain decreased by a mean of -30, -31, -27 and -28mm, respectively (P=.008, P=.0005, P=.002, and P< .0001) in these responders (post-hoc analysis). There was also a significant improvement in the brief pain inventory functional index for all dose-groups (P=.04, .01, .002 and .02, Wilcoxon signed rank test). Furthermore, a decrease in bone alkaline phosphatase in the highest dose-group was demonstrated (P=.0067). All doses were safe and well tolerated.
CONCLUSION: Pain response was seen in up to 71% of the patients with a dose response observed 2weeks after administration. The highly tolerable side-effect profile of radium-223 previously reported was confirmed.
Nilsson S, Strang P, Aksnes AK, Franzèn L, Olivier P, Pecking A, Staffurth J, Vasanthan S, Andersson C, Bruland OS. Are you the author?
Department of Oncology, Radiumhemmet, Karolinska Hospital, SE-171 76 Stockholm, Sweden.
Reference: Eur J Cancer. 2012 Mar;48(5):678-86.