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OncoMatch/Clinical Trials/NCT07666555

A Phase II Clinical Study of the Efficacy and Safety of Culmerciclib Rechallenge in HR-positive, HER2-negative Breast Cancer Patients With Resistance to First-line Endocrine Therapy.

Is NCT07666555 recruiting? Yes, currently enrolling (Jul 2026). This Phase 2 trial studies multiple treatments including CDK4/6 inhibitor and Culmerciclib for breast cancer.

Phase 2RecruitingFudan UniversityNCT07666555Data as of Jul 2026Location: China

Treatment: CDK4/6 inhibitor · Culmerciclib · FulvestrantTo evaluate the efficacy and safety of Culmerciclib combined with fulvestrant compared with investigator-selected CDK4/6 inhibitors combined with fulvestrant in patients with HR-positive/HER2-negative breast cancer who have progressed after first-line endocrine therapy

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Extracted eligibility criteria

Treatments studied

Endocrine / hormonal

Fulvestrant

Other

CDK4/6 inhibitorCulmerciclib

Cancer type

Breast Carcinoma

Biomarker criteria

Required: ESR1 expression (positive)

positive ER expression

Required: HER2 (ERBB2) wild-type (absence)

negative HER2 expression

Performance status

ECOG 0–2(Ambulatory, capable of self-care)

Demographics

Ages ≤ 75
Female only

Prior therapy

Min 1 prior line

Must have received: CDK4/6 inhibitor combined with endocrine therapy — adjuvant or first-line metastatic

Received CDK4/6 inhibitor combined with endocrine therapy as adjuvant endocrine therapy, experienced recurrence or progression during or within 1 year after completion of adjuvant CDK4/6 inhibitor therapy, and did not receive subsequent endocrine therapy; OR recurrence or progression more than 1 year after completion of adjuvant endocrine monotherapy, followed by progression after receiving CDK4/6 inhibitor combined with endocrine therapy as first-line salvage endocrine therapy; OR newly diagnosed locally advanced or metastatic disease, with disease progression after receiving CDK4/6 inhibitor combined with endocrine therapy as first-line salvage endocrine therapy

Lab requirements

Blood counts

Kidney function

Liver function

The functions of vital organs meet the requirements

Structured fields extracted by AI. May contain errors — verify against the official protocol.

Frequently asked questions

Is NCT07666555 currently recruiting?

Yes, this trial is currently recruiting patients.

Is prior treatment required for enrollment?

Yes. Patients must have previously received CDK4/6 inhibitor combined with endocrine therapy.

Does this trial require ESR1?

Yes, ESR1 expression is a required biomarker for enrollment.

Does this trial require ERBB2?

Yes, ERBB2 wild-type is a required biomarker for enrollment.

Is there an age limit?

Yes. Patients must be 75 years or younger.

Is this trial open to male patients?

No. This trial enrolls female patients only.

Could you qualify for this trial?

Enter your biomarker results to see how this trial's eligibility criteria match your specific cancer profile.

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