Tolerability of Dalpiciclib vs. Abemaciclib/Ribociclib in Early HR+/HER2- Breast Cancer

Summary

In recent years, the successful application of cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) has transformed the treatment landscape for HR+/HER2- advanced breast cancer and driven research into their use in adjuvant settings. Large Phase III trials including MONARCH-E and NATALEE have demonstrated that combining CDK4/6i with standard endocrine therapy significantly reduces the risk of recurrence or death in high-risk patients with early breast cancer. This regimen has been recommended by leading domestic and international clinical guidelines. Nevertheless, patients' quality of life, symptom burden and treatment adherence are also critical in clinical practice. Patient-reported outcomes (PROs), especially electronic PROs (ePROs), can effectively complement conventional study endpoints and provide important evidence for the comprehensive evaluation of long-term treatment.

This is a prospective, multicenter, randomized controlled clinical trial. The primary objective is to compare the tolerability of dalpiciclib versus abemaciclib/ribociclib, each combined with standard endocrine therapy, in the adjuvant treatment of patients with high-risk HR+/HER2- early breast cancer. Eligible patients who have received curative local therapy will be randomized to either the experimental group (dalpiciclib plus endocrine therapy) or the control group (ribociclib/abemaciclib plus endocrine therapy). Stratified block randomization will be applied, with stratification factors including menopausal status and prior history of neoadjuvant/adjuvant chemotherapy.

The total duration of endocrine therapy is 5 years. The treatment duration of CDK4/6i is approximately 104 weeks for dalpiciclib, 156 weeks for ribociclib, and 104 weeks for abemaciclib. CDK4/6i will be discontinued in cases of disease recurrence, intolerable toxicity, patient withdrawal, or discontinuation as determined by the investigator. Patients will be regularly asked to complete ePRO questionnaires throughout the treatment period.

Conditions

• Breast Cancer

Interventions

DRUG

Dalpiciclib

Description: 125 mg orally once daily on days 1-21 of a 28-day cycle (3 weeks on, 1 week off) for 24 months (26 cycles). Receive 5 years of standard endocrine therapy. The recommended treatment drugs are as follows: Letrozole Description: 2.5 mg orally once daily continuously for 5 years as part of standard endocrine therapy. Anastrozole Description: 1 mg orally once daily continuously for 5 years as part of standard endocrine therapy. Tamoxifen Description: 10 mg orally twice daily continuously for 5 years as part of standard endocrine therapy. Toremifene Description: 60 mg orally once daily continuously for 5 years as part of standard endocrine therapy. Premenopausal: Preferred treatment is LHRH agonist plus an aromatase inhibitor. Perimenopausal: LHRH agonist and endocrine therapy may be used per investigator's assessment. Goserelin Description: LHRH agonist administered subcutaneously (e.g., 3.6 mg every 28 days) for ovarian function suppression in premenopausal/perimenopausal

DRUG

Abemaciclib/Ribociclib

Abemaciclib Description: Administered according to approved product labeling. Typical dose: 150 mg twice daily continuously for 24 months. Investigator's choice between abemaciclib and ribociclib. Ribociclib Description: Administered according to approved product labeling. Typical dose: 400 mg orally once daily (3 weeks on, 1 week off) for 36 months. Investigator's choice between abemaciclib and ribociclib. Receive 5 years of standard endocrine therapy. The recommended treatment drugs are as follows: Letrozole Description: 2.5 mg orally once daily continuously for 5 years as part of standard endocrine therapy. Anastrozole Description: 1 mg orally once daily continuously for 5 years as part of standard endocrine therapy. Tamoxifen Description: 10 mg orally twice daily continuously for 5 years as part of standard endocrine therapy. Toremifene Description: 60 mg orally once daily continuously for 5 years as part of standard endocrine therapy. Premenopausal: Preferred treatment is LHRH

Sponsors & Collaborators

• Henan Cancer Hospital

  lead OTHER_GOV

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Model

PARALLEL

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2026-08-01

Primary Completion

2028-06-30

Completion

2033-06-30