ARTemis: A randomised trial of bevacizumab with neoadjuvant chemotherapy (NACT) for patients with HER2-negative early breast cancer-Primary endpoint, pathological complete response (pCR)

Background: Bevacizumab (bev) has been used with NACT in breast cancer trials. Geparquinto reported benefit for bev in triple negative (neg) patients (pts) (pCR 36.4% v 27.8% p=0.02), as did CALGB 40603 (pCR 52% v 44%, p=0.057), although the NSABP-B40 study showed benefit in ER-positive (pos) pts (pCR 23.3% v 15.2%, p=0.008). Methods: ARTemis is a randomised phase 3 trial adding bev to NACT (docetaxel (D)-FEC). Pts with HER2-neg invasive breast cancer were eligible. Stratification was by age, ER status (neg: weak pos: strong pos), tumour size (T2:T3/4), clinical involvement of axillary nodes and inflammatory/locally advanced disease. Pts were randomised (1:1) to bev+D-FEC or D-FEC. The primary endpoint was pCR, defined as no residual invasive cancer in the breast or axillary lymph nodes after NACT. 800 pts were required to detect 10% differences in pCR rates, at the 5% (2-sided) level of significance with 85% power. Results: 800 pts were randomised from 66 UK centres (May’09 to Jan’13). 68% were <50 years old, 19% had inflammatory and/or locally advanced disease, 79% of tumours <50mm, 52% clinical node pos and 33% ER-neg. A 2-reader independent review of pathology reports was carried out. Significantly more pts on bev+D-FEC had a pCR (22% (18-27%) vs 17% (13-21%) with D-FEC; p=0.03 [adjusted for stratification factors]). pCR rates differed significantly across ER groups (neg 38%, weak pos 39%, strong pos 7%; p