N-803 in Patients With Progressive Synovial Sarcoma and Myxoid/Round Cell Liposarcoma Previously Treated With Adoptive Cellular Therapy

CO-PRIMARY OBJECTIVES: I. Assess whether nogapendekin alfa inbakicept (N-803) treatment in patients with SS and MRCL that received prior ACT using TCR-T cells expands rare persisting transferred TCR-T cells. II. Assess the safety of N-803 in patients with SS and MRCL that received prior ACT using TCR-T cells. SECONDARY OBJECTIVES: I. Assess for preliminary evidence of N-803 clinical activity by imaging in patients with SS and MRCL that received prior ACT using TCR-T cells. II. Evaluate 6-month progression free survival (PFS) of patients with SS and MRCL treated with N-803 and that have received prior ACT using TCR-T cells. III. Evaluate median progression-free survival (PFS) of patients with SS and MRCL treated with N-803 and that received prior ACT using TCR-T cells. EXPLORATORY OBJECTIVES: I. To perform detailed phenotypic analysis of the persisting transferred T cells in pre-dose and on-treatment leukapheresis samples of patients with SS and MRCL treated with N-803 and that received prior ACT using TCR-T cells. II. To perform detailed analysis of other immunologic subsets, including natural killer (NK) cells and monocytes, following patients with SS and MRCL treated with N-803 and that received prior ACT using TCR-T cells. OUTLINE: Patients receive N-803 subcutaneously (SC) on day 1 of each cycle. Cycles repeat every 14 days for up to 52 cycles in the absence of disease progression or unacceptable toxicity. Patients also undergo leukapheresis during screening up until day 1 cycle 1 and during treatment on day 8 cycle 4. Patients also undergo computed tomography (CT), chest x-ray, or magnetic resonance imaging (MRI) as well as blood sample collection throughout the trial. After completion of study treatment, patients are followed up at 30 days.