This phase II trial studies how well brenetafusp (IMC-F106C) works in treating patients with preferentially expressed antigen of melanoma (PRAME) positive synovial sarcoma and myxoid/round cell liposarcoma that has spread from where it first started (primary site) to other places in the body (metastatic) or that cannot be removed by surgery (unresectable). Brenetafusp (IMC-F106C) is in a new class of immunotherapy called immune mobilizing monoclonal T-cell receptors against cancer (ImmTAC). Brenetafusp (IMC-F106C), may induce changes in body's immune system and may interfere with the ability of tumor cells to grow and spread.
Patients must have metastatic or unresectable synovial sarcoma or myxoid/round cell liposarcoma confirmed by molecular testing (fluorescence in situ hybridization [FISH], immunohistochemistry [IHC] for fusion protein, or next-generation sequencing [NGS])
Patients must be HLA-A*02:01 positive. If HLA-A*02:01 status is already known (from standard of care testing in a Clinical Laboratory Improvement Act [CLIA]-certified laboratory, e.g., in synovial sarcoma), then results from the patient record should be submitted. For patients with unknown HLA-A*02:01 status, pre-enrollment blood should be submitted for testing through the American National Red Cross Histocompatibility Laboratory Services - Philadelphia for testing
Patients must have measurable disease, defined as at least one lesion that can be accurately measured in at least one dimension (longest diameter to be recorded for non-nodal lesions and short axis for nodal lesions) as ≥ 20 mm (≥ 2 cm) by chest x-ray or as ≥ 10 mm (≥ 1 cm) with CT scan, MRI, or calipers by clinical exam
Patients must have received at least one line of systemic therapy (neo/adjuvant chemotherapy counts as a line of therapy). The number of prior lines for metastatic or unresectable disease is limited to three (3)
Patients who received prior treatment with an agent targeting PRAME
Patients who have not recovered from adverse events due to prior anti-cancer therapy (i.e., have residual toxicities > grade 1) with the exception of alopecia
Patients who are receiving any other investigational agents
History of allergic reactions attributed to compounds of similar chemical or biologic composition to brenetafusp (IMC-F106C)