ONO-4578-06:Phase I study of ONO-4578 and letrozole plus CDK4 /6 inhibitors in breast cancer

ONO-4578-06: Phace I , Open-label, non-blind, first-line endocrine therapy with ONO-4578 and standard treatment letrozole and CDK4 /6 inhibitors (palbociclib or abemaciclib) in patients with metastatic or recurrent postmenopausal hormone receptor-positive HER2-negative breast cancer

Status

Active, not recruiting

Phases

Phase 1

Study type

Interventional

Source

JPRN

Registry ID

JPRN-jRCT2031210364

Enrollment

Registered

2021-10-02

Start date

2021-11-09

Completion date

Unknown

Last updated

2026-06-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

breast cancer

Interventions

ONO-4578 is co-administered with the standard treatment letrozole and a CDK4 / 6 inhibitor.

Eligibility

Sex/Gender

Female

Inclusion criteria

Inclusion criteria: 1. Patients with postmenopausal metastatic or recurrent breast cancer 2. Patients with ECOG Performance Status 0 to 1 3. ER-positive, PgR-positive and HER2-negative patients

Exclusion criteria

Exclusion criteria: 1.Patients are unable to swallow oral medications 2.Patients with severe complication

Design outcomes

Primary

Measure	Time frame
Safety and tolerability	—

Contacts

Public ContactSupport Desk JP

Ono Pharmaceutical Co.,LTD.

clinical_trial@ono-pharma.com+81-120278120

Outcome results

None listed

Source: JPRN (via WHO ICTRP) · Data processed: Jul 3, 2026