{"entity":{"id":"action-1","kind":"trial","name":"ACTION-1","aka":[],"tldr":"Tests whether an actinium alpha-radioligand rescues neuroendocrine tumours after lutetium therapy fails.","summary":"ACTION-1, trial NCT05477576 sponsored by Bristol Myers Squibb through RayzeBio, tests whether the actinium-225 alpha-radioligand RYZ101, or 225Ac-DOTATATE, rescues somatostatin-receptor-positive gastroenteropancreatic neuroendocrine tumours after lutetium-177 somatostatin analogue therapy has failed. Its phase 1b established a fixed dose of 10.2 MBq with encouraging responses, the phase 3 against investigator's choice has closed enrolment (ClinicalTrials.gov status active, not recruiting, 343 participants actual, record updated 5 October 2026; primary completion estimated December 2026), and its dosimetry was published in the Journal of Nuclear Medicine in 2026. Nuclide links it to targeted alpha therapy, actinium-225 DOTATATE, lutetium-177 dotatate and the pairing of beta then alpha PRRT. Whether an alpha emitter can overcome resistance to a beta emitter aimed at the same receptor is the question it will answer.","status":"active","asOf":"2026-10-11","links":[{"label":"ClinicalTrials.gov NCT05477576","url":"https://clinicaltrials.gov/study/NCT05477576"},{"label":"ACTION-1 dosimetry (JNM 2026)","url":"https://jnm.snmjournals.org/content/67/8/1239"}],"tags":[],"related":["lu-177","ac-225"],"indications":["neuroendocrine"],"sections":[],"technologies":["targeted-alpha-therapy"],"targets":[],"drugs":["ryz101","lutathera"],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"nct":"NCT05477576","phase":"3","setting":"SSTR-positive GEP-NETs progressing after 177Lu somatostatin-analogue therapy: 225Ac-DOTATATE (RYZ101) vs investigator's choice","sponsor":"BMS (RayzeBio)","enrolled":343,"enrolledBasis":"registry","outcomes":[]},"route":"/trials/action-1/","neighbours":{"isotope":[{"id":"ac-225","kind":"isotope","name":"Actinium-225","route":"/isotopes/ac-225/"},{"id":"lu-177","kind":"isotope","name":"Lutetium-177","route":"/isotopes/lu-177/"}],"indication":[{"id":"neuroendocrine","kind":"indication","name":"Neuroendocrine tumours","route":"/indications/neuroendocrine/"},{"id":"pancreatic-net","kind":"indication","name":"Pancreatic neuroendocrine tumours","route":"/indications/pancreatic-net/"},{"id":"small-intestinal-net","kind":"indication","name":"Small intestinal neuroendocrine tumours","route":"/indications/small-intestinal-net/"}],"technology":[{"id":"targeted-alpha-therapy","kind":"technology","name":"Targeted alpha therapy","route":"/technologies/targeted-alpha-therapy/"}],"drug":[{"id":"ryz101","kind":"drug","name":"Actinium-225 DOTATATE","route":"/drugs/ryz101/"},{"id":"lutathera","kind":"drug","name":"Lutetium-177 dotatate","route":"/drugs/lutathera/"}],"pairing":[{"id":"prrt-then-alpha-net","kind":"pairing","name":"Beta PRRT → alpha PRRT","route":"/pairings/prrt-then-alpha-net/"}],"bottleneck":[{"id":"b-ac225-supply","kind":"bottleneck","name":"Actinium-225 supply","route":"/bottlenecks/b-ac225-supply/"},{"id":"b-rlt-trial-capacity","kind":"bottleneck","name":"Clinical trial capacity for radioligand therapy","route":"/bottlenecks/b-rlt-trial-capacity/"}],"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/"},{"id":"sstr-theranostics-roadmap","kind":"roadmap","name":"SSTR theranostics roadmap: octreotide scintigraphy → 68Ga-DOTATATE → 177Lu-DOTATATE → alpha","route":"/roadmaps/sstr-theranostics-roadmap/"}]}}