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OncoMatch/Clinical Trials/NCT04553770

Trastuzumab Deruxtecan Alone or in Combination With Anastrozole for the Treatment of Early Stage HER2 Low, Hormone Receptor Positive Breast Cancer

Is NCT04553770 recruiting? Yes, currently enrolling (May 2026). This Phase 2 trial studies multiple treatments including Trastuzumab Deruxtecan and Anastrozole for invasive breast cancer.

Phase 2RecruitingJonsson Comprehensive Cancer CenterNCT04553770Data as of May 2026

Treatment: Anastrozole · Trastuzumab DeruxtecanThis phase II trial investigates how well trastuzumab deruxtecan works alone or in combination with anastrozole in treating patients with HER2 low, hormone receptor positive breast cancer. Trastuzumab deruxtecan is a monoclonal antibody, called trastuzumab, linked to a chemotherapy drug called deruxtecan. Trastuzumab attaches to HER2 expressed at low levels on cancer cells in a targeted way and delivers deruxtecan to kill them. Anastrozole works by decreasing estrogen production and suppressing the growth of tumors that need estrogen to grow. This study is evaluating how effective trastuzumab deruxtecan is at treating hormone receptor positive cancer cells that have low levels of HER2 expressed on them when given alone or in combination with anastrozole.

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Extracted eligibility criteria

Cancer type

Breast Carcinoma

Biomarker criteria

Required: HER2 (ERBB2) low expression (IHC 1+ or 2+ (if 2+, FISH non-amplified))

Tumor is HER2-low by immunohistochemistry (IHC), defined as 1+ or 2+, confirmed by central testing... If HER2 is 2+ by IHC, FISH must be performed... and the FISH result must be HER2 non-amplified

Required: ESR1 positive

Tumor is HR positive (HR+) per ASCO CAP guidelines with known estrogen and progesterone receptor status, locally defined

Required: PR (PGR) positive

Tumor is HR positive (HR+) per ASCO CAP guidelines with known estrogen and progesterone receptor status, locally defined

Disease stage

Required: Stage II, IIA, IIB, III

Performance status

ECOG 0–1(Restricted strenuous activity)

Prior therapy

No prior treatment (treatment-naive required)
Max 0 prior lines

Cannot have received: systemic therapy for invasive cancer

Exception: Prior tamoxifen for history of ductal breast carcinoma in situ (DCIS) allowed, but no prior aromatase inhibitor, no prior chemotherapy and no prior HER2-targeted therapy

Prior systemic therapy for invasive cancer

Cannot have received: ipsilateral chest wall radiation

Prior ipsilateral chest wall radiation

Lab requirements

Blood counts

Platelet count >= 100,000/mm^3 (no transfusion within 1 week); hemoglobin >= 9.0 g/dL (no transfusion within 1 week); ANC >= 1500/mm^3 (no G-CSF within 1 week)

Kidney function

Creatinine clearance >= 30 mL/min (Cockcroft-Gault) or serum creatinine <= 1.5 x ULN

Liver function

ALT, AST <= 3 x ULN; total bilirubin <= 1.5 x ULN (Gilbert's syndrome: total bilirubin <= 2.0 x ULN and direct bilirubin within normal limits); serum albumin >= 2.5 g/dL

Cardiac function

Normal cardiac function (LVEF >= 50%) by ECHO or MUGA within 28 days before randomization/enrollment

Normal cardiac function (left ventricular ejection fraction [LVEF] >= 50%)... Platelet count >= 100 000/mm^3... Hemoglobin >= 9.0 g/dL... ANC >=1500/mm^3... Creatinine clearance >= 30 mL/min... ALT, AST <= 3 x ULN... Total bilirubin <= 1.5 x ULN... Serum albumin >= 2.5 g/dL... INR/PT and aPTT <= 1.5 x ULN

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

US trial sites

  • St. Joseph Heritage Healthcare · Fullerton, California
  • Cancer Blood and Specialty Clinic · Los Alamitos, California
  • UCLA / Jonsson Comprehensive Cancer Center · Los Angeles, California
  • Torrance Memorial Physician Network / Cancer Care · Torrance, California
  • PIH Health · Whittier, California

Showing up to 5 US sites. See all sites on ClinicalTrials.gov →

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