# [Ac-225]RTX-2358

Source: https://onco.cc/drugs/rtx-2358/  
OnCo record `rtx-2358` (Treatment). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

[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.

## Fields

- Kind: Treatment
- Status: phase-1
- Last checked: 2026-11-03
- Also known as: RTX-2358; [177Lu]Lu-RTX-2358
- Tags: pipeline; ctgov-ingest
- 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.

## Sources

- Ratio Therapeutics: ratiotx.com: https://ratiotx.com/our-pipeline/
- Ratio Therapeutics: ratiotx.com: https://ratiotx.com/news1/
- Ratio Therapeutics: clinicaltrials.gov: https://clinicaltrials.gov/study/NCT07689643
- ClinicalTrials.gov: trials of RTX-2358: https://clinicaltrials.gov/search?intr=RTX-2358

## Connected records

- cancers: [Non-small-cell lung cancer](https://onco.cc/cancers/nsclc/), [Sarcomas (soft tissue, bone, GIST)](https://onco.cc/cancers/sarcoma/)
- targets: [FAP](https://onco.cc/targets/fap/)
- companies: [Ratio Therapeutics](https://onco.cc/companies/ratio-therapeutics/)
- trials: [Actinium Therapy for Late-stage Aggressive Sarcomas](https://onco.cc/trials/nct07156565/), [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](https://onco.cc/trials/nct07689643/)

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JSON: https://onco.cc/api/v1/entities/rtx-2358.json