{"entity":{"id":"radium-223","kind":"drug","name":"Radium-223 dichloride","aka":[],"tldr":"Radium-223 was the first alpha-emitting drug ever approved (2013). It homes to bone like calcium and treats prostate cancer that has spread only to bone.","summary":"Radium-223 is a calcium mimetic incorporated into bone matrix at sites of metastatic bone turnover, where each decay chain delivers four alpha emissions over a range of a few cells, killing tumour while largely sparing marrow. It is given intravenously to men with symptomatic castration-resistant prostate cancer whose spread is confined to bone without visceral disease. ALSYMPCA showed overall survival of 14.9 versus 11.3 months (HR 0.70) and fewer skeletal events, and it became the first alpha-emitting drug ever approved (2013). ERA 223 showed excess fractures when combined with abiraterone, now contraindicated without bone protection, while PEACE III (2024) with enzalutamide plus bone-protecting agents was positive for rPFS and overall survival. How to sequence it with 177Lu-PSMA therapy is unresolved. Simply put, it is a radioactive calcium look-alike that homes to bone metastases.","status":"approved","asOf":"2026-09-06","wikipedia":"https://en.wikipedia.org/wiki/Radium-223","links":[{"label":"FDA label (DailyMed)","url":"https://dailymed.nlm.nih.gov/dailymed/search.cfm?query=Radium-223%20dichloride"}],"tags":[],"related":["lu-177","ra-223"],"indications":["prostate","prostate-mcrpc"],"sections":[],"technologies":["targeted-alpha-therapy"],"targets":[],"drugs":[],"companies":["bayer"],"institutions":[],"pathways":[],"terms":["alpha-vs-beta"],"trials":["alsympca"],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"brand":"Xofigo","modality":"Targeted alpha therapy (bone-seeking)","mechanism":"Calcium mimetic incorporated into bone matrix at metastases; four alpha emissions per decay chain.","approvals":[{"region":"US","year":2013,"indication":"Symptomatic bone-metastatic CRPC without visceral disease"}],"mechanismSteps":[],"toxicity":[],"access":[],"regulatoryEvents":[]},"route":"/drugs/radium-223/","neighbours":{"isotope":[{"id":"lu-177","kind":"isotope","name":"Lutetium-177","route":"/isotopes/lu-177/"},{"id":"ra-223","kind":"isotope","name":"Radium-223","route":"/isotopes/ra-223/"}],"indication":[{"id":"bone-pain-palliation","kind":"indication","name":"Bone pain palliation from osteoblastic metastases","route":"/indications/bone-pain-palliation/"},{"id":"prostate-mcrpc","kind":"indication","name":"Metastatic castration-resistant prostate cancer","route":"/indications/prostate-mcrpc/"},{"id":"osteosarcoma","kind":"indication","name":"Osteosarcoma","route":"/indications/osteosarcoma/"},{"id":"prostate","kind":"indication","name":"Prostate cancer","route":"/indications/prostate/"}],"technology":[{"id":"radiopharmaceutical-gmp-release","kind":"technology","name":"Radiopharmaceutical GMP and releasing a drug that decays","route":"/technologies/radiopharmaceutical-gmp-release/"},{"id":"targeted-alpha-therapy","kind":"technology","name":"Targeted alpha therapy","route":"/technologies/targeted-alpha-therapy/"}],"company":[{"id":"bayer","kind":"company","name":"Bayer","route":"/companies/bayer/"}],"term":[{"id":"alpha-vs-beta","kind":"term","name":"Alpha vs beta emitters","route":"/terms/alpha-vs-beta/"},{"id":"bone-metastases","kind":"term","name":"Bone metastases and skeletal-related events","route":"/terms/bone-metastases/"},{"id":"flare-phenomenon","kind":"term","name":"Flare phenomenon","route":"/terms/flare-phenomenon/"}],"trial":[{"id":"alsympca","kind":"trial","name":"ALSYMPCA","route":"/trials/alsympca/"}],"drug":[{"id":"samarium-153-lexidronam","kind":"drug","name":"Samarium-153 lexidronam","route":"/drugs/samarium-153-lexidronam/"},{"id":"sr-89-chloride","kind":"drug","name":"Strontium-89 chloride","route":"/drugs/sr-89-chloride/"}],"person":[{"id":"karim-fizazi","kind":"person","name":"Karim Fizazi","route":"/people/karim-fizazi/"}],"section":[{"id":"f-bone-targeted","kind":"section","name":"Bone-targeted radiopharmaceuticals","route":"/fronts/f-bone-targeted/"},{"id":"f-alpha-therapy","kind":"section","name":"Targeted alpha therapy","route":"/fronts/f-alpha-therapy/"}],"pairing":[{"id":"radium223-abiraterone-caution","kind":"pairing","name":"Radium-223 with abiraterone: a caution, not a combination","route":"/pairings/radium223-abiraterone-caution/"}],"roadmap":[{"id":"alpha-therapy-roadmap","kind":"roadmap","name":"Alpha-emitter roadmap: radium-223 → 225Ac-PSMA-617 → a phase 3 pipeline","route":"/roadmaps/alpha-therapy-roadmap/"}],"target":[{"id":"bone-hydroxyapatite","kind":"target","name":"Bone mineral (hydroxyapatite)","route":"/targets/bone-hydroxyapatite/"}]}}