Descartes-08 is a cell therapy wherein T-cells are modified to attack myeloma cells. To modify the cells, new instructions (called RNA) are inserted into the T-cells. These RNA instructions cause the CAR in Descartes-08 T-cells to kill other cells that carry a marker called BCMA. Because the BCMA marker is present on myeloma cells, it is hoped that Decartes-08 will destroy the myeloma cells without harming most other cell types.

Descartes-08 CAR-T cells are altered with RNA, which has a defined half-life. This allows the cells to be administered repetitively in large numbers to kill myeloma cells. It also allows CAR T-cell numbers in the body to be predictable and controlled, potentially reducing risk of side effects.