Abstract P5-10-01: Phase 2 study of anlotinib combined with taxanes and lobaplatin in the neoadjuvant treatment of triple-negative breast cancer: efficacy, safety and biomarker analysis from the SWH-B006 (neoALTALL) trial

Abstract Background: Anlotinib, a novel multi-target tyrosine kinase inhibitor that effectively inhibits VEGFR, PDGFR, FGFR, c-KIT, c-MET, and RET, monotherapy has been proven effective in HER-2 negative metastatic breast cancer, but its efficacy in early-stage triple-negative breast cancer (TNBC) is unknown. This phase 2 study aims to evaluate the efficacy and safety of adding anlotinib to neoadjuvant chemotherapy in patients (pts) with primary TNBC. Methods: Pts with clinical stage II/III TNBC were to be treated with 5 cycles of anlotinib (12mg, d1-14, q3w) plus 6 cycles of taxanes (docetaxel 75 mg/m2 or nab-paclitaxel 125 mg/m2, d1 and d8, q3w) and lobaplatin (30 mg/m2, d1, q3w), followed by surgery. The primary endpoint was pathological complete response (pCR) in the breast and axilla (tpCR; ypT0/is ypN0) and the secondary endpoints include pCR in the breast (bpCR; ypT0/is), event-free survival (EFS), invasive disease-free survival (iDFS), overall survival (OS), and safety. Exploratory study included biomarker analysis and efficacy comparation based on FUSCC classification (IHC-based). Results: From Jan 2021 to Feb 2022, a total of 24 pts were enrolled. The median age was 50 years (range, 26-64), 54% were postmenopausal, 75% were nodal involved, 29% had stage III, and 79% were Ki-67 high (≥30%). At the data cut off time of 30th Jun 2022, all 24 pts received at least one dose of study treatment and underwent surgery. Overall, 21 pts received five courses of anlotinib. Two pts discontinued anlotinb for safety reason, and one pt discontinued anlotinb due to missed dose in cycle 4. After surgery, 14 out of 24 pts achieved a tpCR (58.3%; 95% CI, 36.6%–77.9%), and the bpCR rate was also 58.3% (14/24). Of the 18 pts with the node-positive disease at diagnosis, 15/18 (83.3%) became ypN0. Based on the FUSCC IHC-based subtypes, the tpCR rates were 66.7% (6/9) for BLIS subtype, 80% (4/5) for IM subtype and 0% (0/4) for LAR subtype, respectively. Next-generation sequencing revealed that the most commonly mutated genes in these pts were TP53 (19/21, 90.5%), MYC (7/21, 33.3%), BRCA1 (5/21, 23.8%), PIK3CA (4/21, 19.0%), BCL2L11 (4/21, 19.0%), and RB1 (3/21, 14.3%). Subgroup analysis showed that the tpCR were 71.4% (5/7) and 42.9% (6/14) in MYC-amplified and wild-type pts, respectively, and 80% (4/5) and 43.8% (7/16) in BRCA1-mutated and wild-type pts, respectively. All of 24 pts in the safety population showed at least one treatment emergent adverse events (TEAEs). Grade 3 or 4 TEAEs occurred in 14 pts (58.3%), and the most common events were leucopenia (29.2%; n=7), neutropenia (29.2%; n=7), thrombocytopenia (20.8%; n=5), anemia (16.7%; n=4), hypertension (12.5%; n=3), and oral mucositis (8.3%; n=2), respectively. No treatment-related deaths occurred. Conclusions: The addition of anlotinib to neoadjuvant chemotherapy showed manageable toxicity and promising antitumor activity for pts with early-stage TNBC. The study is still ongoing, and the enrollment has been completed. Clinical trial information: ChiCTR2100043027. Funding: Chia Tai Tianqing Pharmaceutical Group Co., Ltd. L. Corresponding author: Dr. Xiaowei Qi, qxw9908@foxmail.com. Department of Breast and Thyroid Surgery, Southwest Hospital, Army Medical University, Chongqing. Citation Format: Yan Liang, Jing Liu, Tao Luo, Jia Ge, Hao Tian, Guozhi Zhang, Linjun Fan, Lin Ren, Li Chen, Peng Tang, Kai Zhu, Xiuwu Bian, Jun Jiang, Yi Zhang, Xiaowei Qi, Peng Tang, Kai Zhu, Xiuwu Bian, Jun Jiang, Yi Zhang, Xiaowei Qi. Phase 2 study of anlotinib combined with taxanes and lobaplatin in the neoadjuvant treatment of triple-negative breast cancer: efficacy, safety and biomarker analysis from the SWH-B006 (neoALTALL) trial [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P5-10-01.