# ONO-4578-06:Phase I Study of ONO-4578 and Letrozole Plus CDK4 /6 Inhibitors in Breast Cancer

> **NCT06570031** · PHASE1 · ACTIVE_NOT_RECRUITING · sponsor: **Ono Pharmaceutical Co., Ltd.** · enrollment: 46 (actual)

## Conditions studied

- Hormone Receptor-positive Breast Cancer
- HER2-negative Breast Cancer
- Metastatic Breast Cancer
- Recurrent Breast Cancer

## Interventions

- **DRUG:** ONO-4578
- **DRUG:** letrozole
- **DRUG:** Palbociclib
- **DRUG:** abemaciclib

## Key facts

- **NCT ID:** NCT06570031
- **Lead sponsor:** Ono Pharmaceutical Co., Ltd.
- **Sponsor class:** INDUSTRY
- **Phase:** PHASE1
- **Study type:** INTERVENTIONAL
- **Status:** ACTIVE_NOT_RECRUITING
- **Start date:** 2021-11-09
- **Primary completion:** 2026-04-30
- **Final completion:** 2026-04-30
- **Target enrollment:** 46 (ACTUAL)
- **Last updated:** 2025-07-02


## Primary source

ClinicalTrials.gov registry: https://clinicaltrials.gov/study/NCT06570031

## Citation

> US National Library of Medicine, ClinicalTrials.gov registration NCT06570031, "ONO-4578-06:Phase I Study of ONO-4578 and Letrozole Plus CDK4 /6 Inhibitors in Breast Cancer". Retrieved via AI Analytics 2026-06-25 from https://api.ai-analytics.org/clinical/NCT06570031. Licensed CC0.

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