The awarded grant supports a patient-oriented research project to genetically engineer the human immune system to become cancer-targeted and provide benefit to patients with metastatic melanoma, a deadly form of skin cancer currently devoid of successful treatment options.
During the first funding period we initiated a clinical trial where patients with metastatic melanoma receive immune cells that have been re-directed by gene engineering techniques to become melanoma-specific. The immune cells are obtained from the patient’s own blood and they are manipulated in an in-house clinical grade facility for one week to insert into the cells two genes (T cell receptor or TCR genes) that turn them specific melanoma killer cells, called the. The genetic reprogramming of the immune system cells to express TCR genes is done using a crippled virus called a gene transfer vector. These cells undergo extensive testing to meet the standards of the Food and Drug Administration (FDA) before they can be given back to patients.
We give back the TCR re-directed immune cells to patients after receiving a chemotherapy preparative regimen to partially deplete their own immune system so the new cells have the ability to expand. In addition, the patients receive a treatment called high dose interleukin-2 (IL-2) to further allow these cells to expand. Furthermore, these patients receive three doses of dendritic cell vaccines, also generated from the patient’s own blood cells, which further helps the TCR re-directed immune cells to attack the melanoma lesions.
Seven patients have been enrolled onto this study at this time. Two patients are too early to evaluate and in the other patients we have early encouraging evidence of antitumor activity. We are conducting studies to determine how these cells behave in the patients by analyzing if they acquire ability to persist long term, what we call T memory stem cells. These are ongoing studies that will continue to the next funding period.
Finally, we have initiated the work to set up a follow up clinical trial where we will genetically modify patient’s blood stem cells, which we hypothesize will allow the continuous generation of TCR re-directed immune cells starting from the stem cells. This would provide means for immune system regeneration that would have applications to other cancers and non-cancer diseases like infectious diseases and autoimmune diseases. To this end, a new gene transfer vector has initiated clinical grade production to allow us to use it in the proposed next generation clinical trial.