ERBB2 and breast cancer: The ongoing DESTINY-Breast08 trial mainly enrolled breast cancer patients with low HER2 expression, ER or PR-positive (ER or PR ≥ 1%) or ER and PR-negative (ER and PR < 1%), aiming at exploring the safety, tolerability, pharmacokinetics, and antitumor activity of T-DXd in combination with other anticancer drugs, and the results of which are also awaiting maturation.[29] Ongoing studies in people with low HER2 expression also include clinical trials in combination with anastrozole and an EXH 1/2 inhibitor called vale-metostat.