Study in Patients With Relapsed/Refractory Primary Mediastinal Lymphoma Treated With Pembrolizumab or Nivolumab in Combination With Brentuximab Vedotin in a Real-life Context

This study is reviewing real-world outcomes of patients with relapsed or treatment-resistant primary mediastinal B-cell lymphoma (a type of chest lymphoma) who were treated with checkpoint inhibitor drugs like pembrolizumab (alone) or nivolumab combined with brentuximab vedotin. **You may be eligible if...** - You are 18 or older - You have relapsed or refractory primary mediastinal B-cell lymphoma - You received pembrolizumab alone or nivolumab plus brentuximab vedotin as part of routine clinical care (not in a clinical trial) - Your treatment ended before November 2021 **You may NOT be eligible if...** - You received these drugs as part of a clinical trial (not routine care) Talk to your doctor to see if this trial is right for you.