{"entity":{"id":"rtx-2358","kind":"drug","name":"[Ac-225]RTX-2358","aka":["RTX-2358","[177Lu]Lu-RTX-2358"],"tldr":"[Ac-225]RTX-2358 is an experimental small-molecule radioligand therapy from Ratio Therapeutics, in phase 1 trials for FAP-positive soft tissue sarcoma and FAP-positive metastatic non-small cell lung cancer.","summary":"[Ac-225]RTX-2358 (RTX-2358, [177Lu]Lu-RTX-2358) is a small-molecule radioligand therapy (actinium-225; a lutetium-177 version is in an investigator study) from Ratio Therapeutics. A small molecule that carries a radioactive isotope to fibroblast activation protein (FAP) on tumour tissue, so radiation is delivered from inside the body. Its furthest stage is phase 1, for FAP-positive soft tissue sarcoma and FAP-positive metastatic non-small cell lung cancer (lutetium-177 version, investigator study). ClinicalTrials.gov registers it in 2 studies linked below. ATLAS first-in-human phase 1/2 in relapsed or refractory FAP-positive soft tissue sarcoma recruiting (NCT07156565, registered as phase 1). Investigator-led early phase 1 of [177Lu]Lu-RTX-2358 with checkpoint inhibitors in FAP-positive metastatic NSCLC at Union Hospital, Wuhan (NCT07689643). Whether it works in people has not been established unless a trial below reports it.","status":"phase-1","asOf":"2026-11-03","links":[{"label":"Ratio Therapeutics: ratiotx.com","url":"https://ratiotx.com/our-pipeline/"},{"label":"Ratio Therapeutics: ratiotx.com","url":"https://ratiotx.com/news1/"},{"label":"Ratio Therapeutics: clinicaltrials.gov","url":"https://clinicaltrials.gov/study/NCT07689643"},{"label":"ClinicalTrials.gov: trials of RTX-2358","url":"https://clinicaltrials.gov/search?intr=RTX-2358"}],"tags":["pipeline","ctgov-ingest"],"related":[],"cancers":["sarcoma","nsclc"],"sections":[],"technologies":[],"targets":["fap"],"drugs":[],"companies":["ratio-therapeutics"],"institutions":[],"pathways":[],"terms":[],"trials":["nct07156565","nct07689643"],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"provenance":{"editedBy":"OnCo gap audit, class 5 (company pipeline pages and ClinicalTrials.gov v2)","editedOn":"2026-11-03"},"code":"RTX-2358","modality":"Small-molecule radioligand therapy (actinium-225; a lutetium-177 version is in an investigator study)","mechanism":"A small molecule that carries a radioactive isotope to fibroblast activation protein (FAP) on tumour tissue, so radiation is delivered from inside the body.","approvals":[],"mechanismSteps":[],"toxicity":[],"access":[],"regulatoryEvents":[]},"route":"/drugs/rtx-2358/","neighbours":{"cancer":[{"id":"nsclc","kind":"cancer","name":"Non-small-cell lung cancer","route":"/cancers/nsclc/"},{"id":"sarcoma","kind":"cancer","name":"Sarcomas (soft tissue, bone, GIST)","route":"/cancers/sarcoma/"}],"target":[{"id":"fap","kind":"target","name":"FAP","route":"/targets/fap/"}],"company":[{"id":"ratio-therapeutics","kind":"company","name":"Ratio Therapeutics","route":"/companies/ratio-therapeutics/"}],"trial":[{"id":"nct07156565","kind":"trial","name":"Actinium Therapy for Late-stage Aggressive Sarcomas","route":"/trials/nct07156565/"},{"id":"nct07689643","kind":"trial","name":"Safety and Preliminary Efficacy of [177Lu]Lu-RTX-2358 Combined With Immune Checkpoint Inhibitors in Patients With FAP-positive Metastatic Non-Small Cell Lung Cancer","route":"/trials/nct07689643/"}]}}