Background: The goal of this Phase I/II trial is to assess the safety and efficacy of concurrent administration of durvalumab with weekly nab-paclitaxel (100 mg/m2) x 12 followed by dd AC x 4 as neoadjuvant therapy for stage I-III TNBC. The primary efficacy endpoint is pathologic complete response (ypT0 ypN0, pCR). Methods: The Phase I portion of the trial assessed two dose levels of durvalumab; 3 mg/kg and 10 mg/kg iv every 2 weeks in combination with chemotherapy, dose limiting toxicities (DLT) were evaluated over the entire 20 weeks of therapy. The Phase II portion follows Simon’s two step design, with early stopping for futility if < 7 patients achieve pCR among the first 22. Results: No DLT were encountered during the Phase I portion of the trial; the 10 mg/kg was recommended as the phase II dose. Thirty-two patients are enrolled in the trial 14 are still receiving therapy, 16 have completed treatment and underwent surgery and 1 patient withdraw consent. Nine patients (56%, 95% CI: 32%-78%) achieved pCR, 2 of the 4 patients at the 3 mg/kg dose level and 7 of the 12 at the 10 mg/kg dose. Eight patients (25%) experienced grade 3 adverse events including 3 patients with neutropenia (1 neutropenic fever), and one patient each with fatigue, dyspnea, line infection, transaminitis, hypertension/skin rash. No perioperative adverse events were seen. Conclusions: Concomitant administration of durvalumab with weekly nab-paclitaxel and sequential ddAC neoadjuvant chemotherapy is safe and the pCR rates appear to be higher than what is expected with chemotherapy alone. Clinical trial information: NCT02489448