Results
tumor, neutropenia, toxicities, TNBC, /HER2- disease
TUMOR, NEUTROPENIA, DISEASE, TRIPLE-NEGATIVE BREAST CANCER, ADVERSE EVENT
No dose-limiting toxicities were identified in the dose escalation cohort (n = 6). In the dose expansion cohort, an additional 38 patients were enrolled for a total of 44 patients, including 31 patients (70.4%) with hormone receptor-positive (HR +)/HER2- disease, 12 patients (27.3%) with triple-negative breast cancer (TNBC), and 1 patient (2.3%) with HR + /HER2 + disease. Patients had a median age of 56 years (range 33–82 years), 1 prior line of hormone therapy (range 0–6), and 2 prior lines of chemotherapy (range 0–7). CBR was 79.5% (35/44; 7 partial response, 28 stable disease) and the median DOR was 16.4 weeks (range 13.8–21.1 weeks). Median PFS was 16.4 weeks (95% CI: 13.8–21.1 weeks). The most common grade 3/4 adverse event was neutropenia (47.7%, n = 21). Fourteen of 26 patients (53.8%) with circulating tumor cell (CTC) data were CTC-positive (