A phase I clinical trial marks the start of early testing for new cancer drug IMGN289. IMGN289 is a so-called antibody-drug conjugate (ADC). ADCs combine antibodies (immune system proteins designed to bind to specific targets) with chemotherapy drugs to help steer the chemotherapy agents specifically towards tumors and spare healthy tissues. IMGN289 consists of an antibody that binds to EGFR, a protein expressed in many lung cancer tumors, connected to a cell-killing agent called DM1. The trial will study patients with non-small cell lung cancer (NSCLC) and other cancers that express high levels of EGFR. After determining the highest IMGN289 dose that can safely be administered to patients, the study will evaluate the effectiveness of the drug in different patient subgroups.