SHR1701 Alone or in Combination With SHR2554 in Relapsed or Refractory Classical Hodgkin Lymphoma

This study is testing two experimental drugs — SHR1701 (an immune checkpoint blocker) and SHR2554 (an EZH2 inhibitor) — alone or together for people with Hodgkin lymphoma that has come back or stopped responding to treatment. **You may be eligible if...** - You have confirmed Hodgkin lymphoma that has relapsed or is no longer responding to treatment - You are between 12 and 75 years old - You have had at least two previous rounds of treatment and have been off treatment for at least 4 weeks - You are generally well enough to care for yourself (good performance status) - You have at least one measurable tumor - Your bone marrow, liver, kidneys, and heart are functioning adequately **You may NOT be eligible if...** - You have an autoimmune disease or need steroid/immune-suppressing medications - You have uncontrolled serious medical conditions - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.