Multicenter phase 2-3 trial of neoadjuvant chemotherapy with or without olaparib for BRCA1/2-related breast cancer

The randomized phase 2-3 PARTNER trial, at 23 centers in the UK, evaluated addition of olaparib to neoadjuvant chemotherapy for breast cancer with germline BRCA1 and BRCA 2 pathogenic variants (gBRCAm). There was no statistical difference between the olaparib-chemotherapy group and the chemotherapy-alone group for the primary endpoint pathological complete response rate (64.1% versus 69.8%; p=0.59). However, survival outcomes at 36 months demonstrated improved event-free survival (96.4% versus 80.1%; p=0.04), overall survival (100% versus 88.2%; p=0.04) and breast cancer-specific survival (100% versus 88.2%; p=0.04). The authors conclude that PARTNER identied a safe and tolerable schedule combining neoadjuvant chemotherapy with olaparib, resulting in improved survival outcomes compared with chemotherapy alone.