Zongertinib: First Approval.

Zongertinib (HERNEXEOS) is a small molecule, irreversible, HER2-specific tyrosine kinase inhibitor being developed by Boehringer Ingelheim for the treatment of advanced solid tumours with HER2 aberrations. Zongertinib selectively inhibits HER2-expressing cells, including those with HER2 mutations, while sparing cells expressing wild-type EGFR. It received its first approval under accelerated approval in August 2025 in the USA following positive results from the Beamion LUNG-1 phase Ia/Ib trial in patients with previously treated HER2-mutant non-small cell lung cancer (NSCLC). This article summarizes the milestones in the development of zongertinib leading to this first approval for the treatment of adult patients with unresectable or metastatic NSCLC whose tumours have HER2 tyrosine kinase domain activating mutations, as detected by an FDA-approved test, and who have received prior systemic therapy.