# ESG401

Source: https://onco.cc/drugs/esg401/  
OnCo record `esg401` (Treatment). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

ESG401 is an experimental drug that delivers chemotherapy to cells bearing TROP2. Early breast-cancer response results are being followed by larger trials.

## Summary

ASCO 2025 abstract 1044 reports 156 patients enrolled in ESG401-101 at the October 23, 2024 cutoff. Distinct efficacy populations included 37 late-line TNBC patients (ORR 35.1%, 95% CI 20.2 to 52.5) and 35 first-line TNBC patients (ORR 83.0%, 95% CI 66.4 to 93.4). These nonrandomized cohorts have different lines of treatment and cannot be pooled or compared directly with phase 3 ADC trials. Grade 3 or higher treatment-related events were mainly neutropenia and leukopenia. The phase 1/2 NCT04892342 is completed; later registered phase 3 development is separate from this early evidence.

## Fields

- Kind: Treatment
- Status: phase-3
- Last checked: 2026-10-06
- Tags: pipeline; ctgov-ingest
- Modality: ADC
- Mechanism: Humanized anti-TROP2 IgG1 conjugated to SN-38 through a stable cleavable linker.
- Payload: SN-38 (TOP1 inhibitor)

## Sources

- Publisher abstract: https://doi.org/10.1200/jco.2025.43.16_suppl.1044
- ClinicalTrials.gov NCT04892342: https://clinicaltrials.gov/study/NCT04892342

## Connected records

- cancers: [HR-positive / HER2-negative breast cancer](https://onco.cc/cancers/breast-hr-positive/), [Triple-negative breast cancer (TNBC)](https://onco.cc/cancers/tnbc/)
- targets: [TROP2](https://onco.cc/targets/trop2/)
- companies: [Qilu Pharmaceutical](https://onco.cc/companies/qilu-pharmaceutical/)
- trials: [A Phase III Study of ESG401 for Locally Advanced or Metastatic HR+/HER2- Breast Cancer](https://onco.cc/trials/nct06383767/), [A Phase III Study of ESG401 for Unresectable Recurrent or Metastatic Triple-Negative Breast Cancer](https://onco.cc/trials/nct06732323/), [Study of ESG401 in Adults With Solid Tumors](https://onco.cc/trials/nct04892342/)

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