# Lerociclib

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

## TL;DR

Lerociclib is a CDK4/6 inhibitor from G1 Therapeutics developed in China by Genor Biopharma, in a phase 3 trial with letrozole for hormone receptor-positive breast cancer.

## Summary

G1 Therapeutics designed lerociclib (G1T38) as a CDK4/6 inhibitor that could be taken continuously without a break; it licensed Chinese rights to Genor Biopharma, which runs the phase 3 LEONARDA trials with letrozole or fulvestrant in HR-positive, HER2-negative advanced breast cancer. EQRx briefly held Western rights before returning them.

## Fields

- Kind: Treatment
- Status: phase-3
- Last checked: 2026-09-16
- Also known as: G1T38
- Tags: pipeline; ctgov-ingest
- Code: GB491
- Modality: Oral CDK4/6 inhibitor
- Mechanism: Inhibits cyclin-dependent kinases 4 and 6, arresting hormone receptor-positive breast cancer cells in G1, the class of palbociclib, ribociclib and abemaciclib.

## Sources

- ClinicalTrials.gov: trials of Lerociclib: https://clinicaltrials.gov/search?intr=GB491

## Connected records

- cancers: [HR-positive / HER2-negative breast cancer](https://onco.cc/cancers/breast-hr-positive/)
- technologies: [Small-molecule kinase inhibitors](https://onco.cc/technologies/kinase-inhibitors/)
- targets: [CDK4/6](https://onco.cc/targets/cdk4-6/)
- trials: [A Study of GB491 in Combination With Letrozole in Patients With HR Positive and HER2 Negative Advanced Breast Cancer](https://onco.cc/trials/nct05851014/)

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JSON: https://onco.cc/api/v1/entities/lerociclib.json