ESMO 2021 | HER2+ and TNBC highlights from ESMO 2021

Gaia Griguolo, MD, Instituto Oncologico Veneto I.R.C.C.S, Padova, Italy, comments on key clinical trials in HER2-positive and triple negative breast cancer (TNBC) presented at ESMO 2021. To begin with, the practice-changing DESTINY-Breast03 trial (NCT03529110) demonstrated a significantly improved progression-free survival (PFS) for patients with HER-2 positive metastatic BC treated with trastuzumab deruxtecan (T-DXd) over patients treated with ado-trastuzumab emtansine (T-DM1) in the second-line setting. Whilst this trial did not investigate the efficacy of T-DXd in patients with active brain metastases, brain metastases are very common in HER-2 positive BC. In fact, the KATHERINE study (NCT01772472) showed that in their cohort, almost half of the patients with early BC relapsed with active brain metastases after treatment with T-DM1. It is therefore important to assess T-DXd in this patient population. With regards to TNBC, the KEYNOTE-522 trial (NCT03036488) reported significant improvements in patients with PD-L1-positive tumors treated with neoadjuvant pembrolizumab plus chemotherapy followed by adjuvant pembrolizumab versus patients treated with placebo and neoadjuvant chemotherapy. This interview took place at the European Society for Medical Oncology (ESMO) 2021 congress.