Moreover, in the phase 2 DESTINY-Lung02 study comparing the 5.4 mg/kg vs. 6.4 mg/kg dosing of T-DXd in HER2-mutant NSCLC patients, there was a higher incidence of drug-related pneumonitis (12.9% vs. 28.0%, respectively) with the higher dose [22]. Here, ERBB2 is linked to pneumonitis.