Chimeric Antigen Receptor Treatment Targeting CD70 (SEVENTY)

This study is for patients who have a type of blood cancer that expresses the protein CD70, which includes acute myeloid leukemia (AML), T-cell leukemia or B-cell leukemia (and the leukemia has come back or has not gone away after standard of care treatment).

As there are limited or no remaining standard treatments available to treat this cancer, subjects are being asked to volunteer to be in a gene transfer research study using special immune cells to create a specialized immune cell that will recognize a protein called CD70 that is expressed on the outside surface of the leukemia cells in a subject's body.

The body has different ways of fighting infection and disease. No one way seems perfect for fighting cancers. This research study combines different ways of fighting disease by using T cells and "arming" them to recognize a specific protein on cancer cells. T cells, also called T lymphocytes, are special infection-fighting blood cells that can kill other cells including tumor cells. T cells by themselves have been used to treat patients with cancers and have shown promise, but have not been strong enough to cure most patients.

T lymphocytes can kill tumor cells but there normally are not enough of them to kill all the tumor cells. Some researchers have taken T cells from a person's blood, grown more of them in the laboratory and then given them back to the person.

The protein used in this study is called anti-CD70. It has been developed from human CD27 on normal T cells, since it is the natural binding partner that can connect with CD70. This anti-CD70 protein sticks to leukemia cells when it binds to CD70. CD70 binders have been used to treat people with leukemia. For this study, anti-CD70 has been changed so that instead of floating free in the blood it is now joined to the T cells. When an antibody is joined to a T cell in this way it is called a chimeric receptor or "CAR T cell". The doctors then made another change to cause these T cells to kill any cell that has CD70. This causes the "CAR T cells" to kill blood cancer cells which are confirmed to have CD70.

In the laboratory, investigators have found that T cells work better if there are proteins added which stimulate T cells. The anti-CD70 (CD27) protein is unique because it can bind to CD70 on leukemia cells but also stimulates the T cells that express it. Adding the CD27 makes the cells grow better and may help them to last longer in the body, thus giving the cells a better chance of killing the leukemia cells.

These CD70 "CAR" T cells are investigational products not approved by the Food and Drug Administration.

The purpose of this study is to find a dose of CAR T cells that is safe, to learn what the side effects are and to see whether this therapy might help people with leukemia.