OncoMatch/Clinical Trials/NCT07037199
Efficacy and Safety of Trastuzumab Rezetecan Followed by CDK4/6 Inhibitors and Endocrine Therapy in HR+/HER2-Low/Ultra-Low Advanced Breast Cancer
Is NCT07037199 recruiting? Yes, currently enrolling (May 2026). This Phase 2 trial studies Trastuzumab rezetecan + CDK4/6 inhibitors + endocrine therapy for advanced breast cancer.
Treatment: Trastuzumab rezetecan + CDK4/6 inhibitors + endocrine therapy — This multicenter, prospective phase II clinical trial evaluates the efficacy and safety of sequential Trastuzumab rezetecan followed by dalpiciclib plus endocrine therapy (fulvestrant or aromatase inhibitors) in 45 patients with HR+/HER2-low/ultra-low advanced breast cancer. Enrolled patients will receive Trastuzumab rezetecan monotherapy for 6-8 cycles until clinical benefit, then transition to CDK4/6 inhibitors with endocrine therapy until disease progression or unacceptable toxicity. The primary endpoint is progression-free survival (PFS), with secondary endpoints including objective response rate (ORR), overall survival (OS), and treatment-related adverse events (TRAEs). The study will be conducted at Sun Yat-sen Memorial Hospital and collaborating centers.
Check if I qualifyExtracted eligibility criteria
Cancer type
Breast Carcinoma
Biomarker criteria
Required: HER2 (ERBB2) HER2-low (IHC 1+ or IHC 2+/ISH-negative) (IHC 1+ or IHC 2+/ISH-negative)
HER2-low: IHC 1+ or IHC 2+/ISH-negative
Required: HER2 (ERBB2) HER2-ultra-low (IHC 0 with membranous staining >0 but <1+) (IHC 0 with membranous staining >0 but <1+)
HER2-ultra-low: IHC 0 with membranous staining (>0 but <1+)
Required: ESR1 positive (≥10% tumor cells with ER nuclear staining) (≥10% tumor cells with ER nuclear staining)
HR+: ≥10% tumor cells with ER/PR nuclear staining (verified by central pathology review)
Required: PR (PGR) positive (≥10% tumor cells with PR nuclear staining) (≥10% tumor cells with PR nuclear staining)
HR+: ≥10% tumor cells with ER/PR nuclear staining (verified by central pathology review)
Disease stage
Metastatic disease required
Recurrent/metastatic disease; locally recurrent cases must be deemed unresectable by investigators. Measurable disease per RECIST 1.1 (including lytic/mixed bone-only metastases).
Performance status
ECOG 0–1(Restricted strenuous activity)
Prior therapy
Must have received: endocrine therapy — advanced/metastatic
Disease progression after endocrine therapy (ET) + CDK4/6 inhibitor in the advanced/metastatic setting
Must have received: CDK4/6 inhibitor — advanced/metastatic
Disease progression after endocrine therapy (ET) + CDK4/6 inhibitor in the advanced/metastatic setting
Cannot have received: HER2-targeted therapy
Prior anti-HER2 therapy at any stage (including HER2-ADCs such as T-DM1 or T-DXd)
Lab requirements
Blood counts
anc >1.5×10⁹/l; platelets >90×10⁹/l; hb >90 g/l.
Kidney function
bun/cr ≤1.5×uln.
Liver function
total bilirubin ≤uln (≤2×uln if gilbert's syndrome). alt/ast ≤1.5×uln (≤5×uln with liver metastases). alkaline phosphatase ≤2.5×uln.
Cardiac function
lvef ≥50%; qtcf <470 ms.
Structured fields extracted by AI. May contain errors — verify against the official protocol.
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