# The pharmacokinetics and Concentration-QTc analysis of a new etomidate analog ET-26-HCl: a phase I trial in healthy Chinese subjects

**Authors:** Kun He, Wenyu Zhang, Xiangran Kong, Lize Li, Lei Diao, Qing Wen, Guohai Su, Xiaoran Yang, Hongyan Zhao

PMC · DOI: 10.3389/fphar.2025.1534717 · 2025-04-17

## TL;DR

A new anesthetic drug, ET-26-HCl, was tested in healthy people to assess its safety and effectiveness, showing no risk of heart rhythm issues.

## Contribution

ET-26-HCl is a novel etomidate analog with reduced adrenal impact and no QT interval prolongation risk, validated through a phase I trial.

## Key findings

- ET-26-HCl showed rapid onset and recovery with no QT interval prolongation risk at tested doses.
- Pharmacokinetic data confirmed safety and dose-dependent sedative effects in healthy Chinese subjects.

## Abstract

Methoxetamine hydrochloride (ET-26-HCl) is a novel short-acting intravenous general anesthetic that retains the advantages of etomidate while minimizing its impact on adrenal cortical function. A single-center, randomized, open-label, placebo-controlled clinical trial was conducted using concentration-QTc (C-QTc) model analysis to evaluate the pharmacokinetics, clinical sedative effect, safety, and potential risk of QT interval prolongation of ET-26-HCl at doses of 0.8 mg/kg (the clinical dosage) and 2.8 mg/kg. In the 0.8 mg/kg group, the mean peak concentration (C
max) of ET-26 was 1,510 ng/mL with upper limits of the 90% confidence interval (CI) for QTcF interval corrected by baseline and placebo (ΔΔQTcF) falling within an acceptable range, not exceeding ±10 ms (−1.543 ms to +2.788 ms). The 2.8 mg/kg group exhibited a higher C
max value for ET-26, along with corresponding mean ΔΔQTcF values that remained below the ±10 ms threshold limit. Based on the established C-QTc model analysis, it is predicted that the upper limit of 90% CI for the mean ΔΔQTcF corresponding to ET-26 at twice the C
max of 0.8 mg/kg is ≤ ±10 ms. The study findings in conjunction with the C-QTc model demonstrated the rapid onset and recovery properties of ET-26. Furthermore, increased exposure and dose-dependent sedative/hypnotic effects were observed, with no risk of QT prolongation for this investigational drug, thereby ensuring patient safety and minimizing potential risks in its clinical application.

ClinicalTrials.gov CTR20233230.

## Linked entities

- **Chemicals:** etomidate (PubChem CID 36339)

## Full-text entities

- **Diseases:** QT interval prolongation (MESH:D008133)
- **Chemicals:** etomidate (MESH:D005045), ET-26-HCl (MESH:C000621869), ET-26 (-)
- **Species:** Homo sapiens (human, species) [taxon 9606]

## Figures

7 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12043489/full.md

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Source: https://tomesphere.com/paper/PMC12043489