Phase II neoadjuvant pyrotinib combined with epirubicin and cyclophosphamide followed by docetaxel in HER2-low–expressing and HR-positive early or locally advanced breast cancer (PILHLE-001): A single-arm trial.

• DOI: 10.1200/jco.2022.40.16_suppl.tps620
• Publication Date: 2022-06-06T15:51:55Z
• Authors: Yuan Xia; Wenqian Yang; Ya-Ping Yang; Yingying Zhu; Yinduo Zeng; Tao Qin; Shijie Jia; Jiayi Chen; Chang Gong
• Keywords: Epirubicin; Regimen; Neoadjuvant Therapy

TPS620 Background: As a latent new subtype, HER2-low-expressing breast cancer has attracted increasing attention. However, HER2-low-expressing/HR-positive early or locally advanced (E/LABC) the lowest pathological complete response (pCR) rate among all types of cancer. Pyrotinib, small-molecule HER1/HER2/HER4 tyrosine kinase inhibitor, combined with chemotherapy regimen showed excellent efficacy and safety in treatment patients HER2-positive early, metastatic In-vitro experiment pyrotinib can significantly inhibit colony formation cell lines different HER2 expression levels including HER2-low-expressimg [immunohistochemistry (IHC) 2+/in situ hybridization (ISH) negative]. Therefore, investigator-driven, ongoing PILHLE-001 trial been conducted to evaluate potential role neoadjuvant plus E/LABC, which may provide novel therapeutic strategy for these patients. Methods: PILHLE-001, as single-arm, phase Ⅱ study, is first combine (defined IHC 2+ ISH negative) HR-positive (ER PR > 1% stained cells) E/LABC (cT1c histologically involved lymph nodes ≥cT2). Patients who have 1+, severe heart diseases basic gastrointestinal are excluded. The 80% power detect true difference from previous reported pCR 17.5%, an expected 35% at two-sided alpha level 0.05. Considering drop 10%, total 46 will be needed. Since May 19, 2021 until now, 19 enrolled. All eligible receive 320mg orally daily cycles (epirubicin 90 mg/m² intravenously cyclophosphamide 600 on day 1 four 3-week followed by docetaxel 100 cycle). primary outcome pCR, defined no residual invasive tumor cells axillary nodes, regardless ductal carcinoma (ypT0/is ypN0) after treatment. secondary outcomes include Miller-Payne grade, burden score, overall rate, conservation disease-free survival, exploratory biomarkers drug related safety. Primary analyzed intention‐to‐treat population set population. Long-term assessed later enough follow-up. Clinical information: NCT05165225.