Background: Platinum-based chemotherapy has been reported to have efficacy in patients with Triple Negative Breast Cancer (TNBC). Germline BRCA1/2 mutation status has been shown to be predictive of platinum response in patients with metastatic TNBC. In the neoadjuvant setting some, but not all patients with sporadic TNBC also achieve a pathologic complete response (pCR). This study evaluated the efficacy and toxicity of neoadjuvant treatment with carboplatin and eribulin in patients with early stage TNBC, and assessed the role of a HRD (homologous recombination deficiency) test to predict response. Methods: Patients with histologically confirmed early stage TNBC received carboplatin AUC 6 iv every 21 days and eribulin 1.4 mg/m² day1 and day 8 every 21 days for four cycles. The primary endpoint of the study was pCR, with secondary endpoints including clinical response rate and safety of the combination. Tumor specimens were evaluated for BRCA1/BRCA2 mutations, BRCA1 promoter methylation, and HRD status. Results: A total of 30 patients enrolled in the study. 13 (43.3%) achieved pCR. The combination was safe with mostly grade 1 and 2 toxicities. 28 pre-treatment samples were available for HR deficiency assessment and 26 obtained passing HRD scores. HR deficiency (HRD positive with HRD score ≥ 42), significantly predicted pCR in the full cohort (P = 0.0012) and in the subset of BRCA1/2 wild type patients (P= 0.0018). Conclusions: The combination of carboplatin and eribulin is safe and efficacious in the treatment of early stage TNBC. The use of an HRD test can predict pCR after carboplatin and eribulin treatment in this patient population and with further validation can be used to identify patients beyond those with a germline BRCA mutation who will respond to a platinum-containing regimen. Clinical trial information: NCT01372579