B-cells and plasma cells with EBV have been found in brain lesions in MS patients. And studies have shown that immune activity against EBV correlates with the development of lesions and increases in MS patients’ disability.
Researchers believe B-cells and plasma cells with EBV are involved in the destruction of myelin, a protective coating of neurons whose deterioration is involved in MS. This idea is in part supported by the recent approval of Ocrevus (ocrelizumab). Ocrevus targets B-cells, but not plasma cells.
ATA188 uses T-cells derived from a patient or donated as starting material. With a patient’s own cells, or autologous cells, researchers first gather T-cells from a blood sample. Then they train the cells to recognize markers of EBV before injecting them back into the patient. This approach makes it possible to find and eliminate virus-specific B-cells and plasma cells in the brain and spinal cord.
The patients in the trial received four escalating doses of ATA188 developed from their own T-cells. After the last dose, at six weeks, they were followed for 20 weeks.
Symptoms of three of the six patients improved after ATA188 treatment. They reported less fatigue, better quality of life, increased ability to perform daily activities, and improved hand movement and coordination. Two of the three had secondary and one primary progressive MS.
Over the 26 weeks of the trial, none of the six patients’ disease worsened, as measured by the Expanded Disability Status Scale (EDSS). The symptom improvements correlated with increased immune cell response toward EBV, researchers said.
