Culmerciclib Combined With Letrozole and Dual HER2 Blockade as Neoadjuvant Therapy for HR+/HER2+ Breast Cancer

August 26, 2026 updated by: Jianyi Li, Shengjing Hospital

A Single-Arm, Prospective, Multicenter Phase II Study of Culmerciclib Plus Letrozole and Trastuzumab (TQB211)/Pertuzumab (TQB2440) as Neoadjuvant Therapy in Patients With HR-Positive/HER2-Positive Early or Locally Advanced Breast Cancer

This is a single-arm, prospective, multicenter, phase II clinical study evaluating the efficacy and safety of a chemotherapy-free neoadjuvant regimen in patients with HR-positive/HER2-positive (HR+/HER2+) early or locally advanced breast cancer.

Approximately 33 treatment-naive patients with stage II-III (AJCC 8th edition) HR+/HER2+ breast cancer will receive 5 cycles of neoadjuvant treatment with culmerciclib (a CDK4/6 inhibitor) plus letrozole, trastuzumab (TQB211) and pertuzumab (TQB2440), followed by definitive breast surgery.

The primary endpoint is breast pathological complete response rate (bpCR, ypT0/is ypN0). Secondary endpoints include objective response rate (ORR), residual cancer burden (RCB), Ki67 change rate, patient-reported outcomes, and safety assessed per CTCAE v5.0.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

HR-positive/HER2-positive breast cancer accounts for approximately 10% of all breast cancers and shows lower pathological complete response rates to neoadjuvant therapy compared with the HR-negative/HER2-positive subtype. Crosstalk between HER2 and ER signaling pathways contributes to resistance to endocrine and anti-HER2 therapy. Preclinical evidence suggests that CDK4/6 inhibitors synergize with anti-HER2 therapy and may restore tumor sensitivity to HER2 blockade.

Eligible patients receive:

  • culmerciclib 180 mg orally once daily, in 28-day cycles, for 5 cycles;
  • Letrozole 2.5 mg orally once daily, in 28-day cycles, for 5 cycles;
  • Trastuzumab (TQB211) 8 mg/kg loading dose followed by 6 mg/kg intravenously every 3 weeks, for 6 doses;
  • Pertuzumab (TQB2440) 840 mg loading dose followed by 420 mg intravenously every 3 weeks, for 6 doses.

Tumor response is assessed by imaging (ultrasound, mammography, and MRI) according to RECIST 1.1. After completion of 5 cycles of neoadjuvant treatment, patients undergo definitive breast cancer surgery, and postoperative pathology is evaluated for bpCR and RCB. Adverse events are assessed per CTCAE v5.0. Exploratory analyses will investigate correlations between biomarkers and treatment response.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
33

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • China
    • Liaoning
      • Shenyang, Liaoning, China, 110042
        • Liaoning cancer Hospital & Institute
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Histologically confirmed HR-positive (ER >=50%, PR >=10%) and HER2-positive (IHC 3+ or ISH+) breast cancer;
  • Clinical stage II-III (AJCC 8th edition);
  • Treatment-naive: no prior systemic anti-tumor therapy for breast cancer;
  • ECOG performance status 0-1;
  • Adequate organ function;
  • Signed informed consent.

Exclusion Criteria:

  • Distant metastasis (stage IV disease);
  • Prior chemotherapy, endocrine therapy, or anti-HER2 therapy for the current breast cancer;
  • Severe cardiac dysfunction or left ventricular ejection fraction (LVEF) below the institutional lower limit of normal;
  • Pregnancy or lactation;
  • Any other condition that, in the investigator's opinion, makes the patient unsuitable for the study.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Culmerciclib + Letrozole + TQB211 + TQB2440
Patients receive Culmerciclib plus letrozole, trastuzumab (TQB211) and pertuzumab (TQB2440) as neoadjuvant therapy for 5 cycles, followed by definitive breast cancer surgery.
Drug: Culmerciclib
180 mg orally once daily, in 28-day cycles, for a total of 5 cycles.
Drug: Letrozole
2.5 mg orally once daily, in 28-day cycles, for a total of 5 cycles.
Drug: Trastuzumab (TQB211)
8 mg/kg intravenous loading dose, followed by 6 mg/kg intravenously every 3 weeks, for a total of 6 doses.
Drug: Pertuzumab (TQB2440)
840 mg intravenous loading dose, followed by 420 mg intravenously every 3 weeks, for a total of 6 doses

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Breast Pathological Complete Response Rate (bpCR)
Time Frame: At time of surgery, after completion of 5 cycles of neoadjuvant therapy (approximately 5 months from treatment start)
Proportion of patients achieving ypT0/is ypN0 (no invasive cancer in the breast and no involved axillary lymph nodes), assessed by postoperative pathology.
At time of surgery, after completion of 5 cycles of neoadjuvant therapy (approximately 5 months from treatment start)

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Objective Response Rate (ORR)
Time Frame: At end of neoadjuvant treatment (approximately 5 months from treatment start)
Proportion of patients achieving complete response (CR) or partial response (PR) assessed by imaging according to RECIST 1.1.
At end of neoadjuvant treatment (approximately 5 months from treatment start)
Residual Cancer Burden (RCB)
Time Frame: At time of surgery (approximately 5 months from treatment start)
Residual cancer burden index and class (RCB-0, I, II, III) assessed by postoperative pathology.
At time of surgery (approximately 5 months from treatment start)
Ki67 Change Rate
Time Frame: From baseline to surgery (approximately 5 months)
Change in Ki67 proliferation index from baseline (pre-treatment biopsy) to surgery.
From baseline to surgery (approximately 5 months)
Patient-Reported Outcomes (PRO)
Time Frame: From baseline through end of treatment (approximately 5 months)
Patient-reported quality of life and symptom measures collected during treatment.
From baseline through end of treatment (approximately 5 months)
Incidence and Severity of Adverse Events
Time Frame: From first dose through 30 days after surgery (approximately 6 months)
Number and severity of adverse events graded according to CTCAE v5.0.
From first dose through 30 days after surgery (approximately 6 months)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Shengjing Hospital

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
September 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
March 30, 2028

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
June 30, 2028

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
August 26, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 26, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
August 31, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
August 31, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 26, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • IIT2026052

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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