A Study of Ladiratuzumab Vedotin in Advanced Solid Tumors

Inclusion Criteria * All Cohorts * Measurable disease according to RECIST v1.1 as assessed by the investigator * Eastern Cooperative Oncology Group (ECOG) Performance Score of 0 or 1 * Cohort 1: SCLC (Parts A and B) * Must have extensive stage disease * Must have disease progression during or following prior platinum-based systemic chemotherapy for extensive stage disease; * No more than 1 prior line of cytotoxic chemotherapy for extensive disease stage * May have received prior anti-PD(L)1 therapy * Cohort 2: NSCLC-squamous (Parts A and B) * Must have unresectable locally advanced or metastatic disease * Must have disease progression during or following systemic therapy * Participants must have progressed during or after a platinum-based combination therapy administered for the treatment of metastatic disease, OR * Participants must have progressed within 6 months of last dose of platinum-based adjuvant, neoadjuvant, or definitive chemotherapy, or concomitant chemoradiation regimen for early stage or locally advanced stage disease. * Participants with known epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK), reactive oxygen species (ROS), BRAF, or other actionable mutations are not eligible * No more than 1 prior line of cytotoxic chemotherapy for their advanced disease * Must have received prior anti-PD(L)1 therapy, unless contraindicated * Cohort 3: NSCLC-nonsquamous (Parts A and B) * Must have unresectable local…