Safety and Efficacy of XmAb18087 ± Pembrolizumab in Advanced Merkel Cell Carcinoma or Extensive-stage Small Cell Lung Cancer

This is a Phase 1b/2, multiple-dose study designed to describe safety and efficacy, and to assess PK and immunogenicity of XmAb18087 monotherapy and in combination with pembrolizumab in participants with metastatic Merkel cell (MCC) or locoregional MCC that has recurred after locoregional therapy with surgery and/or radiation therapy, and mAb18087 monotherapy in participants with extensive-stage small cell lung cancer (SCLC) that has progressed after standard therapies. This study was terminated by the sponsor. No participants enrolled in Part B.