Third-Party Natural Killer Cells and Mogamulizumab for the Treatment of Relapsed or Refractory Cutaneous T-cell Lymphomas or Adult T-Cell Leukemia/Lymphoma

This study is testing a combination of natural killer (NK) cell therapy — immune cells from a donor, engineered to attack cancer — together with a targeted antibody drug (mogamulizumab) for people with relapsed or treatment-resistant cutaneous T-cell lymphoma (a rare skin cancer) or adult T-cell leukemia/lymphoma. **You may be eligible if:** - You are 18 or older - You have cutaneous T-cell lymphoma (stage IB–IVB) that has returned or stopped responding after at least one prior systemic therapy, OR adult T-cell leukemia/lymphoma that has been treated with at least one prior chemotherapy - You are in good overall health (ECOG 0–1) - Your blood counts, kidney, and liver function meet minimum requirements - Your life expectancy is at least 90 days **You may NOT be eligible if:** - Your lymphoma has spread to the brain or spinal fluid - You have active serious infections, active hepatitis B or C, or HIV with CD4 count below 350 - You have had a solid organ transplant - You have previously received mogamulizumab for reasons other than disease progression - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.