{"entity":{"id":"alpha-therapy-roadmap","kind":"roadmap","name":"Alpha-emitter roadmap: radium-223 → 225Ac-PSMA-617 → a phase 3 pipeline","aka":[],"tldr":"Alpha particles carry much more energy over a much shorter distance than the beta particles used in Lutathera and Pluvicto, so they can be more powerful against small clusters of cancer cells. The first alpha drug was approved in 2013; a wave of alpha versions of existing beta drugs is now in late-stage testing, and the isotopes are still scarce.","summary":"Alpha-particle therapy began clinically with radium-223 dichloride, approved by the FDA on 15 May 2013 for bone metastases in prostate cancer after the ALSYMPCA trial, though radium-223 is a bone-seeker rather than a targeted radioligand. The targeted-alpha era proper starts with Kratochwil and colleagues at Heidelberg and the Joint Research Centre Karlsruhe, who treated the first patients with 225Ac-PSMA-617 in 2014 and reported complete responses in two heavily pretreated men with metastatic castration-resistant prostate cancer in 2016, followed by empirical dose-finding in a larger series in 2017.\n\nThat compassionate-use experience seeded a pipeline of sponsor-run trials repeating the beta-to-alpha substitution across targets: 225Ac-DOTATATE (RYZ101, RayzeBio/BMS) in the ACTION-1 trial for neuroendocrine tumours progressing after 177Lu-DOTATATE; 225Ac-PSMA-I&T (FPI-2265, Fusion Pharmaceuticals/AstraZeneca) in AlphaBreak for prostate cancer after 177Lu-PSMA; 225Ac-PSMA-617 (AAA817, Novartis) in a phase 3 programme; and 212Pb-DOTAMTATE (AlphaMedix, RadioMedix/Orano Med/Sanofi), whose phase 2 ALPHAMEDIX-02 study reported that it met all primary efficacy endpoints in October 2025. Every one of these programmes is capacity-constrained: actinium-225 in particular is scarce, and lead-212 and actinium-225 production are both being scaled by companies such as TerraPower Isotopes and Orano Med.\n\nThe unresolved questions are whether alpha activity will translate into a survival benefit large enough for approval once the phase 3 readouts arrive (2026-2028 on current registry estimates), whether the added myelotoxicity and xerostomia seen in compassionate-use series are tolerable at scale, and whether supply can grow fast enough to support first-line or earlier-line use rather than remaining a last-resort option after beta radioligand therapy fails.","asOf":"2026-09-22","links":[{"label":"FDA: Alsympca (radium-223 dichloride) approval, May 2013","url":"https://www.accessdata.fda.gov/drugsatfda_docs/nda/2013/203971Orig1s000TOC.cfm"},{"label":"Kratochwil et al., 225Ac-PSMA-617 for PSMA-targeted alpha-radiation therapy (J Nucl Med 2016)","url":"https://pubmed.ncbi.nlm.nih.gov/27390158/"},{"label":"RayzeBio/ClinicalTrials.gov: ACTION-1 (NCT05477576)","url":"https://clinicaltrials.gov/study/NCT05477576"},{"label":"Sanofi: AlphaMedix (212Pb-DOTAMTATE) ALPHAMEDIX-02 phase 2 results, October 2025","url":"https://www.sanofi.com/en/media-room/press-releases/2025/2025-10-08-05-00-00-3163053"},{"label":"TerraPower Isotopes: Bellwether Laboratory groundbreaking, May 2026","url":"https://www.terrapower.com/TerraPower-Isotopes-Breaks-Ground-on-Worlds-Largest-Actinium-225-Manufacturing-Facility-in-Philadelphia"}],"tags":[],"related":["lu-177","ac-225","ra-223","pb-212"],"indications":[],"sections":[],"technologies":["targeted-alpha-therapy","actinium-225-supply","radioligand-therapy","prrt"],"targets":[],"drugs":["radium-223","ryz101","fpi-2265","ac225-psma","alphamedix"],"companies":["rayzebio","fusion-pharma","novartis","orano-med","radiomedix","terrapower-isotopes"],"institutions":[],"pathways":[],"terms":[],"trials":["alsympca","action-1","alphabreak","alphamedix-02"],"people":["clemens-kratochwil","uwe-haberkorn"],"bottlenecks":[],"keyPapers":["paper-alsympca-radium-223-nejm-2013"],"journals":[],"dependsOn":[],"notes":[],"steps":[{"era":"2013","title":"Radium-223: the first alpha emitter approved","description":"The FDA approves radium-223 dichloride on 15 May 2013 for symptomatic bone metastases in castration-resistant prostate cancer, based on the ALSYMPCA trial (median overall survival 14.9 vs 11.3 months). Radium-223 is a bone-seeking calcium mimetic rather than a receptor-targeted ligand, but it establishes that an alpha emitter can be given systemically and safely.","refs":["radium-223","alsympca","paper-alsympca-radium-223-nejm-2013"],"status":"historic"},{"era":"2014-2017","title":"First-in-human targeted alpha therapy: 225Ac-PSMA-617","description":"Clinical investigation of 225Ac-PSMA-617 begins in 2014 at Heidelberg University Hospital with the Joint Research Centre Karlsruhe. Kratochwil et al. report complete biochemical and imaging responses in two heavily pretreated men with mCRPC in 2016 (J Nucl Med), then empirical dose-finding (100 kBq/kg every 8 weeks) in a larger series in 2017, establishing the first targeted-alpha treatment protocol in humans.","refs":["clemens-kratochwil","uwe-haberkorn"],"status":"historic"},{"era":"2018-2023","title":"Sponsor-run alpha programmes multiply","description":"Compassionate-use experience is followed by company-sponsored trials repeating the beta-to-alpha substitution across targets and companies: RYZ101 (225Ac-DOTATATE) enters ACTION-1 for GEP-NETs progressing after 177Lu-SSA therapy; FPI-2265 (225Ac-PSMA-I&T) enters AlphaBreak for mCRPC after 177Lu-PSMA; Novartis begins a phase 3 programme for AAA817 (225Ac-PSMA-617); and RadioMedix/Orano Med complete enrolment of the phase 2 ALPHAMEDIX-02 trial of 212Pb-DOTAMTATE in 2023.","refs":["action-1","alphabreak","alphamedix-02","rayzebio","fusion-pharma","novartis","orano-med","radiomedix"],"status":"historic"},{"era":"2024-2026","title":"Supply scales and the first phase 2 readouts land","description":"TerraPower Isotopes announces it is producing actinium-225 at commercial scale via weekly production runs from October 2024. 212Pb-DOTAMTATE receives FDA Breakthrough Therapy designation in 2024, and the ALPHAMEDIX-02 phase 2 study reports in October 2025 that it met all primary efficacy endpoints (ORR 60% in PRRT-naive patients), the first positive alpha-PRRT phase 2 readout in neuroendocrine tumours.","refs":["terrapower-isotopes","alphamedix-02","orano-med"],"status":"current"},{"era":"2026-2029","title":"Phase 3 readouts and a step-change in actinium-225 capacity","description":"ACTION-1, AlphaBreak and the AAA817 phase 3 programme are all due to reach their primary completion dates between late 2026 and 2028, which will determine whether alpha radioligands can be filed for approval as a post-beta salvage option. TerraPower Isotopes breaks ground on a $450m Philadelphia facility in May 2026 intended to increase global actinium-225 production capacity twentyfold.","refs":["action-1","alphabreak","novartis","terrapower-isotopes"],"status":"emerging"},{"era":"2029+","title":"Speculative: alpha therapy in earlier lines","description":"If phase 3 trials read out positively and actinium-225 and lead-212 supply scales as planned, alpha radioligands could move from post-beta salvage into earlier lines, including hormone-sensitive prostate cancer, and combine with PARP inhibitors or immunotherapy. This depends on both an approval and a resolved supply chain; neither is confirmed as of this record's `asOf` date.","refs":["targeted-alpha-therapy","idea-alpha-first-mhspc","idea-alpha-after-adc"],"status":"speculative"}],"watch":[{"item":"ACTION-1 (RYZ101, RayzeBio/BMS) phase 3 primary completion","expected":"Primary Completion (Estimated): 2026-12","source":"https://clinicaltrials.gov/study/NCT05477576","refs":["action-1","rayzebio"]},{"item":"AlphaBreak (FPI-2265, Fusion Pharmaceuticals) phase 2 primary completion","expected":"Estimated Completion: July 23, 2026","source":"https://www.ancora.ai/en/detailsradiopharm/NCT06402331","refs":["alphabreak","fusion-pharma"]},{"item":"AAA817 (Novartis, PSMAcTION, NCT06780670) phase 3 primary completion","expected":"Primary completion date: Jun 27, 2028 (Anticipated)","source":"https://www.allclinicaltrials.com/study/NCT06780670","refs":["novartis"]},{"item":"TerraPower Isotopes' Philadelphia cGMP actinium-225 facility begins production","expected":"Production of cGMP actinium-225 beginning in 2029","source":"https://www.terrapower.com/TerraPower-Isotopes-announces-cGMP-manufacturing-facility","refs":["terrapower-isotopes"]}]},"route":"/roadmaps/alpha-therapy-roadmap/","neighbours":{"isotope":[{"id":"ac-225","kind":"isotope","name":"Actinium-225","route":"/isotopes/ac-225/"},{"id":"pb-212","kind":"isotope","name":"Lead-212","route":"/isotopes/pb-212/"},{"id":"lu-177","kind":"isotope","name":"Lutetium-177","route":"/isotopes/lu-177/"},{"id":"ra-223","kind":"isotope","name":"Radium-223","route":"/isotopes/ra-223/"}],"technology":[{"id":"actinium-225-supply","kind":"technology","name":"Actinium-225 supply: thorium stocks, accelerators and radium targets","route":"/technologies/actinium-225-supply/"},{"id":"prrt","kind":"technology","name":"Peptide receptor radionuclide therapy (PRRT)","route":"/technologies/prrt/"},{"id":"radioligand-therapy","kind":"technology","name":"Radioligand therapy (beta emitters)","route":"/technologies/radioligand-therapy/"},{"id":"targeted-alpha-therapy","kind":"technology","name":"Targeted alpha therapy","route":"/technologies/targeted-alpha-therapy/"}],"drug":[{"id":"alphamedix","kind":"drug","name":"212Pb-DOTAMTATE","route":"/drugs/alphamedix/"},{"id":"ryz101","kind":"drug","name":"Actinium-225 DOTATATE","route":"/drugs/ryz101/"},{"id":"ac225-psma","kind":"drug","name":"Actinium-225 PSMA agents","route":"/drugs/ac225-psma/"},{"id":"fpi-2265","kind":"drug","name":"FPI-2265","route":"/drugs/fpi-2265/"},{"id":"radium-223","kind":"drug","name":"Radium-223 dichloride","route":"/drugs/radium-223/"}],"company":[{"id":"fusion-pharma","kind":"company","name":"Fusion Pharmaceuticals (AstraZeneca)","route":"/companies/fusion-pharma/"},{"id":"novartis","kind":"company","name":"Novartis","route":"/companies/novartis/"},{"id":"orano-med","kind":"company","name":"Orano Med","route":"/companies/orano-med/"},{"id":"radiomedix","kind":"company","name":"RadioMedix","route":"/companies/radiomedix/"},{"id":"rayzebio","kind":"company","name":"RayzeBio (BMS)","route":"/companies/rayzebio/"},{"id":"terrapower-isotopes","kind":"company","name":"TerraPower Isotopes","route":"/companies/terrapower-isotopes/"}],"trial":[{"id":"action-1","kind":"trial","name":"ACTION-1","route":"/trials/action-1/"},{"id":"alphabreak","kind":"trial","name":"AlphaBreak (FPI-2265) & AcTION (225Ac-PSMA-617)","route":"/trials/alphabreak/"},{"id":"alphamedix-02","kind":"trial","name":"ALPHAMEDIX-02","route":"/trials/alphamedix-02/"},{"id":"alsympca","kind":"trial","name":"ALSYMPCA","route":"/trials/alsympca/"}],"person":[{"id":"clemens-kratochwil","kind":"person","name":"Clemens Kratochwil","route":"/people/clemens-kratochwil/"},{"id":"uwe-haberkorn","kind":"person","name":"Uwe Haberkorn","route":"/people/uwe-haberkorn/"}],"paper":[{"id":"paper-alsympca-radium-223-nejm-2013","kind":"paper","name":"ALSYMPCA: alpha emitter radium-223 and survival in metastatic prostate cancer with bone metastases","route":"/key-papers/paper-alsympca-radium-223-nejm-2013/"}],"idea":[{"id":"idea-alpha-after-adc","kind":"idea","name":"Alpha radioligands after ADC failure","route":"/ideas/idea-alpha-after-adc/"},{"id":"idea-alpha-first-mhspc","kind":"idea","name":"Alpha-emitting PSMA therapy at first metastatic diagnosis","route":"/ideas/idea-alpha-first-mhspc/"}]}}