Treatment Developed for Immune Systems of Chemo Patients

(National Institutes of Health)

Researchers from University of Pennsylvania in Philadelphia have devised a treatment to repair the immune systems of leukemia patients undergoing chemotherapy using the patients’ own infection-fighting cells. The findings from the team that included participants from M.D. Anderson Cancer Center and Baylor College of Medicine in Houston were presented yesterday at the annual meeting of the American Society of Hematology in San Diego.

Chemotherapy with the drug fludarabine is often used to treat patients with chronic lymphocytic leukemia (CLL), but fludarabine has harsh side effects, particularly the destruction of their healthy immune cells, called T lymphocytes, leading to serious infections. “Fludarabine is a double-edged sword,” says Stephen Schuster, a hematology-oncology professor at Penn’s medical school. “Although it is very active at killing CLL cells, it is also very active at killing normal cells in the immune system.”

The Pennsylvania/Texas team developed a system of alleviating this problem by using the patients’ own T cells that fight infections, and tested this method in a clinical study. The researchers isolated healthy T lymphocytes from the blood of 34 patients before they started chemotherapy. The team then produced more of the T cells from each patient at Penn’s Clinical Cell and Vaccine Production Facility using the university’s technology that induces the cells to quickly grow and multiply. After chemotherapy, the researchers then infused the expanded T cells back into the patient.

Immediately after chemotherapy and prior to T cell infusion, the median count of CD4 T cells that support the immune system for fludarabine-treated patients was 119 cells/ml blood and the median CD8 or infection-fighter T cell count was 80 cells/ml. Some 30 days after the treatment where the patients received the infusion of their own T cells, the median cell counts were in the normal range, at 373 cells/ml for CD4 and 208 cells/ml for CD8 cells. The T cell numbers remained in the normal range beyond 90 days, which indicates that the transfer of the patients’ own T cells helps repair the patients’ immune systems.

The success of this method was not uniform however. Patients who had a complete response to chemotherapy had a more robust T cell recovery than the patients who had only a partial response. “Somehow, the cancer seems to interfere with recovery of the immune system,” says Schuster.

Read more: FDA Gives Accelerated Approval to Lymphoma Drug

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