Testing the Combination of Nivolumab and ASTX727 for Relapsed or Refractory B-Cell Lymphoma

This study tests combining nivolumab (an immunotherapy drug) with ASTX727 (a DNA-modifying drug) for people with B-cell lymphoma or Hodgkin lymphoma that has come back or stopped responding to treatment. **You may be eligible if...** - You have relapsed or treatment-resistant diffuse large B-cell lymphoma (DLBCL) or Hodgkin lymphoma - For DLBCL: you have failed at least one prior chemotherapy and are not eligible for a stem cell transplant - For Hodgkin lymphoma: you have relapsed after at least 2 prior therapies, and are not eligible for or have already had an autologous stem cell transplant - You have measurable disease by imaging **You may NOT be eligible if...** - You have active autoimmune disease requiring treatment - You have significant heart disease - You have uncontrolled infections - You are pregnant or breastfeeding - You have HIV or active hepatitis B or C Talk to your doctor to see if this trial is right for you.