A Phase I Study to Investigate the Tolerability and Safety of ONO-4685 Given as Monotherapy in T Cell Lymphoma and CLL/SLL

This is an early-phase safety study for a new drug called ONO-4685, used alone, in people with certain types of T-cell lymphoma or a blood cancer called CLL/SLL. T-cell lymphomas are cancers of a specific type of immune cell. The study is mainly focused on finding a safe dose and understanding how the drug behaves in the body. **You may be eligible if...** - You have been diagnosed with one of the following: peripheral T-cell lymphoma (PTCL), angioimmunoblastic T-cell lymphoma (AITL), cutaneous T-cell lymphoma (such as mycosis fungoides or Sézary syndrome), or chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) - Your cancer has come back or stopped responding to prior treatments, and no better standard treatment options are available - You are in reasonably good physical health and your organs are functioning adequately - You are 18 years of age or older **You may NOT be eligible if...** - You have had certain serious infections like active hepatitis B/C or HIV - You have had a stem cell transplant recently or have graft-versus-host disease - You have significant heart, liver, or kidney problems - You are pregnant or breastfeeding - You have active brain involvement from your cancer Talk to your doctor to see if this trial is right for you.