HIV used to treat leukemia

The protocol for the new treatment involves removing patients' cells through an apheresis process similar to blood donation, and modifying them in Penn's cell and vaccine production facility. Scientists there reprogram the patients' T cells to target tumor cells through a gene modification technique using a HIV-derived lentivirus vector. The vector encodes an antibody-like protein, called a chimeric antigen receptor (CAR), which is expressed on the surface of the T cells and designed to bind to a protein called CD19.

The modified cells are then infused back into the patient's body following lymphodepleting chemotherapy. Once the T cells start expressing the CAR, they focus all of their killing activity on cells that express CD19, which includes CLL and ALL tumor cells, and normal B cells. All of the other cells in the patient that do not express CD19 are ignored by the modified T cells, which limits systemic side effects typically experienced during traditional therapies.

the media hype over “HIV” based cancer therapies is misleading – the lentivirus used was really only a gene delivery vehicle (in theory, other non-viral based methods could have been used just as easily)

Exactly, with the exception that HIV targets T-cells and is thus the logical choice of virus for the cell type.