Adaptimmune Announces Responses In Second Solid Tumor Indication

(RTTNews) - Adaptimmune Therapeutics plc (ADAP) reported three partial responses--two confirmed and one to be confirmed--, and one stable disease in the first four patients dosed with NY-ESO SPEAR T-cells in a second solid tumor: myxoid/ round cell liposarcoma or MRCLS.

Patients tolerated treatment well with cytokine release syndrome or CRS managed following standard treatment guidelines. GlaxoSmithKline plc (GSK, GSK.L) exercised its option to exclusively license the right to research, develop, and commercialize NY-ESO SPEAR T-cell therapy program in September 2017. Transition of this program to GSK is ongoing.

MRCLS and synovial sarcoma are both considered soft tissue sarcomas. MRCLS is a type of liposarcoma, characterized by the proliferation of adipocyte (fat cell) precursors called lipoblasts that have undergone differentiation arrest. This malignancy arises from a translocation between chromosomes 12 and 16 resulting in a fusion protein that blocks adipocyte differentiation and promotes malignant transformation.

Synovial sarcoma is characterized by a different chromosomal translocation involving the X chromosome and chromosome 18 and, unlike the known immature fat cell cellular origin of MRCLS, the cell of origin for synovial sarcoma remains unknown.