Making the donation
Our investigational treatment involves the identification of a healthy matched donor according to Human Leukocyte Antigen (HLA) type. HLAs are proteins on the surface of cells that allow the immune system to distinguish the body’s own cells from invaders such as bacteria and viruses. Usually, the best donors are relatives of the patient, such as siblings.
Patients follow the same process to find an appropriate match according to standard matching protocols. For our current clinical trial we are partnering with the National Marrow Donor Program (NMDP), the most diverse marrow registry in the world to identify an appropriate match for patients.
Engineering the HSCs
Once a match is found, the donor provides cells via apheresis (a procedure to remove the HSCs from the donor). We then use CRISPR-Cas9 to remove a particular marker on the outside of the cells. Preclinical data and extensive research using existing genome databases show that this marker does not affect cellular function, but distinguishes these modified cells from cancer cells.
Transplanting the new cells
The patient will need to go to one of the transplant centers where the new eHSCs are transplanted into the patient. We deliver our engineered HSCs using the same transplant procedure that is currently the standard of care. After the eHSCs engraft (start to grow and make healthy blood cells), the patient is primed for administration of the companion therapeutic, if necessary.
Targeted therapy post-transplant
After transplant, a targeted therapy would be given to the patient. Vor Bio’s initial clinical trial is using Mylotarg™, an FDA-approved therapy that targets the cell marker that has been removed from the donated cells. These engineered HSCs are designed to be “invisible” so that the targeted therapy only kills the cancer cells in the blood, not the healthy cells.