ERBB3 and non-small cell lung carcinoma: HER3 is expressed in 82.7% of primary NSCLC.135 Recent evidence suggest that anti-EGFR TKIs increase HER3 expression in EGFR-mutant NSCLC, enhancing HER3-DXd activity.136 In the phase I trial NCT03260491, patients with EGFR-mutant NSCLC progressing to an anti-EGFR TKI received HER3-DXd achieving a mPFS of 8.2 months, while mOS was not reached; ORR was 39%, indicating an interesting anticancer activity of the compound.