Efficacy and Safety of Culmerciclib Plus Aromatase Inhibitors in a Response-Adapted Neoadjuvant Strategy for Highly Proliferative ER-Positive/HER2-Negative Breast Cancer

NCT07616453 | Recruiting Phase 2

• 1 other identifier: 2026-0417
• Study Type: interventional
• Target: 45
• Locations: 1 country
• Sites: 1

Brief Summary

This prospective, response-adapted phase II study evaluates the efficacy and safety of neoadjuvant culmerciclib in combination with aromatase inhibitors in patients with highly proliferative ER-positive/HER2-negative breast cancer. All patients initially receive induction treatment with culmerciclib plus endocrine therapy, followed by on-treatment assessment of biological and clinical response. Patients demonstrating an adequate response continue the same regimen, whereas those with a suboptimal response are transitioned to alternative treatment strategies prior to surgery. This adaptive approach aims to optimize treatment selection, improve therapeutic efficacy, and avoid unnecessary exposure to ineffective therapy.

Conditions

HR+/HER2- Early Breast Cancer

Outcome Measures

Primary Outcomes (1)

• Complete cell cycle arrest (CCCA)

  Ki67≤2.7%

  4 weeks

Secondary Outcomes (5)

• the proportion of patients with Residual Cancer Burden (RCB) class 0-1

  24 weeks

• Total Pathological Complete Response (tpCR) Rate

  24 weeks

• Objective Response Rate (ORR)

  24 weeks

• Event-Free Survival (EFS)

  Approximately five years

• Adverse Event (AE)

  Approximately three years

Study Arms (1)

Culmerciclib plus AI

EXPERIMENTAL

Drug: Culmerciclib; Drug: Aromatase Inhibitors

Interventions

Culmerciclib DRUG

CDK2/4/6 inhibitor

Culmerciclib plus AI

Aromatase Inhibitors DRUG

Letrozole or anastrozole

Culmerciclib plus AI

Eligibility Criteria

• Age: 18 Years - 75 Years
• Sex: female
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Ki-67 ≥20% assessed on core needle biopsy samples. Newly diagnosed, treatment-naïve patients with stage I-IIIA disease according to the AJCC 8th edition.
• Eastern Cooperative Oncology Group (ECOG) performance status of 0-1.
• Adequate bone marrow function:
• Absolute neutrophil count ≥1.5 × 10⁹/L (without growth factor support within 14 days);
• Platelet count ≥100 × 10⁹/L (without transfusion or supportive therapy within 7 days);
• Hemoglobin ≥100 g/L (without transfusion within 7 days).
• Adequate hepatic and renal function:
• Total bilirubin ≤1 × upper limit of normal (ULN);
• Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤3 × ULN (≤5 × ULN in patients with liver metastases);
• Blood urea nitrogen and serum creatinine ≤1.5 × ULN, and creatinine clearance ≥50 mL/min (calculated using the Cockcroft-Gault formula).

You may not qualify if:

• Concurrent treatment with other anticancer agents. Bilateral breast cancer, inflammatory breast cancer, or occult breast cancer. Stage IV breast cancer. Breast cancer not confirmed by histopathology. History of other malignancies within the past 5 years, except for adequately treated carcinoma in situ of the cervix.
• Severe dysfunction of major organs, including heart, liver, or kidneys. Conditions affecting oral drug administration or absorption, including inability to swallow, chronic diarrhea, or intestinal obstruction.
• Participation in another interventional clinical trial within 4 weeks prior to enrollment.
• Known hypersensitivity to any component of the study drugs; history of immunodeficiency, including HIV infection, active hepatitis B or C infection, other acquired or congenital immunodeficiency disorders, or history of organ transplantation.
• History of significant cardiovascular disease, including but not limited to clinically significant arrhythmias requiring treatment, myocardial infarction, heart failure, or any other cardiac condition deemed unsuitable by the investigator.
• Pregnant or breastfeeding women; women of childbearing potential with a positive pregnancy test at baseline, or unwilling to use effective contraception during the study period.
• Any serious concomitant disease that, in the investigator's judgment, may compromise patient safety or compliance with the study, including but not limited to uncontrolled hypertension, severe diabetes, or active infection.
• History of neurological or psychiatric disorders, including epilepsy or dementia.
• Any other condition that, in the investigator's opinion, makes the patient unsuitable for participation in the study.

Sponsors & Collaborators

• Second Affiliated Hospital, School of Medicine, Zhejiang University: lead

Study Sites (1)

2nd Affiliated Hospital, School of Medicine, Zhejiang University

Hangzhou, Zhejiang, 310009, China

RECRUITING

MeSH Terms

Interventions

Aromatase Inhibitors

Intervention Hierarchy (Ancestors)

Steroid Synthesis Inhibitors; Enzyme Inhibitors; Molecular Mechanisms of Pharmacological Action; Pharmacologic Actions; Chemical Actions and Uses; Estrogen Antagonists; Hormone Antagonists; Hormones, Hormone Substitutes, and Hormone Antagonists; Physiological Effects of Drugs

Study Officials

• Yiding Chen

  Second Affiliated Hospital, School of Medicine, Zhejiang University

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Yunxiang Zhou

CONTACT

15868131018; yxzhou@zju.edu.cn

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SEQUENTIAL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: May 24, 2026
• First Posted: June 1, 2026
• Study Start: May 6, 2026
• Primary Completion (Estimated): May 5, 2028
• Study Completion (Estimated): May 5, 2033
• Last Updated: June 1, 2026

Record last verified: 2026-05

Locations

CN (1)