ExteNET was a pivotal phase 3, global, multicenter, randomized, double-blind, placebo-controlled study1
2840 women with early-stage HER2+ breast cancer; locally confirmed HER2 status; all patients had prior trastuzumab-based therapy within 2 years*
invasive disease-free survival (iDFS)†
overall survival, DFS-DCIS, distant DFS, time to distant recurrence, CNS metastases, safety
nodes 0, 1-3 vs 4+; ER/PR status; concurrent vs sequential trastuzumab-based therapy
CNS: central nervous system; DCIS: ductal carcinoma in situ; DFS: disease-free survival; ER: estrogen receptor; HER2: human epidermal growth factor receptor 2; PR: progesterone receptorSelect exclusion criteria: clinically significant cardiac, GI, or psychiatric comorbidities; inability to swallow pills.
Invasive disease-free survival (iDFS), defined as the time between the date of randomization to the first occurrence of invasive recurrence (local/regional, ipsilateral, or contralateral breast cancer), distant recurrence, or death from any cause, with 2 years and 28 days of follow-up.
The iDFS results of ExteNET are supported by an exploratory analysis of 5-year follow-up with 74.5% (2117/2840) of patients reconsented.
Patient characteristics were well balanced in the ExteNET trial
ER: estrogen receptor; PR: progesterone receptor
Percentage is based on the number of hormone receptor-positive patients. Tumors were assessed as being ER or PR positive on the basis of local pathology laboratory cutoffs. There was no protocol specification as to whether a 1% or 10% threshold should be used.
The number of patients who received neoadjuvant chemotherapy was 342 (24%) in the neratinib group and 379 (27%) in the placebo group.