ADCs directed against HER2(Syntarga)

Antibody–drug conjugates (ADCs) have demonstrated effectiveness in treating various cancers, particularly exhibiting specificity in targeting human epidermal growth factor receptor 2 (HER2)‐positive breast cancer. Recent advancements in phase 3 clinical trials have broadened current understanding of ADCs, especially trastuzumab deruxtecan, in treating other HER2‐expressing malignancies. This expansion of knowledge has led to the US Food and Drug Administration's approval of trastuzumab deruxtecan for HER2‐positive and HER2‐low breast cancer, HER2‐positive gastric cancer, and HER2‐mutant nonsmall cell lung cancer. Concurrent with the increasing use of ADCs in oncology, there is growing concern among health care professionals regarding the rise in the incidence of interstitial lung disease or pneumonitis (ILD/p), which is associated with anti‐HER2 ADC therapy. Studies on anti‐HER2 ADCs have reported varying ILD/p mortality rates. Consequently, it is crucial to establish guidelines for the diagnosis and management of ILD/p in patients receiving anti‐HER2 ADC therapy. To this end, a panel of Chinese experts was convened to formulate a strategic approach for the identification and management of ILD/p in patients treated with anti‐HER2 ADC therapy. This report presents the expert panel's opinions and recommendations, which are intended to guide the management of ILD/p induced by anti‐HER2 ADC therapy in clinical practice.

ERBB2 amplification in lung cancer remains poorly characterized. HER2 (encoded by ERBB2) is a transmembrane tyrosine kinase capable of ligand-independent dimerization and signaling when overexpressed, and a common cause of HER2 overexpression is ERBB2 amplification. Here, we evaluated the clinicopathologic and genomic characteristics of ERBB2-amplified NSCLC and explored a HER2 antibody-drug conjugate (ADC) therapeutic strategy.

Our institutional next-generation DNA sequencing data (OncoPanel) from 5769 NSCLC samples (5075 patients) were queried for cases having high-level ERBB2 amplification (≥6 copies). Clinical and demographic characteristics were extracted from the electronic medical records. Efficacy of the pan-ERBB inhibitor afatinib or HER2 ADCs (trastuzumab deruxtecan and trastuzumab emtansine) was evaluated in NSCLC preclinical models and patients with ERBB2 amplification.

High-level ERBB2 amplification was identified in 0.9% of lung adenocarcinomas and reliably predicted overexpression of HER2. ERBB2 amplification events are detected in two distinct clinicopathologic and genomic subsets of NSCLC: as the sole mitogenic driver in tumors arising in patients with a smoking history or as a concomitant alteration with other mitogenic drivers in patients with a light or never smoking history. We further reveal that trastuzumab deruxtecan is effective therapy in in vitro and in vivo preclinical models of NSCLC harboring ERBB2 amplification and report two cases of clinical activity of an anti-HER2 ADC in patients who acquired ERBB2 amplification after previous targeted therapy.

High-level ERBB2 amplification reliably predicts HER2 overexpression in patients with NSCLC, and HER2 ADC is effective therapy in this population.