A new approach involving billions of clones of patients’ own tumor-fighting cells in combination with a specific form of chemotherapy is showing promise in the fight against advanced melanoma. The results of the Fred Hutchinson Cancer Research Center study are published in the March 5 Early Edition of the Proceedings of the National Academy of Sciences.
The study, led by Cassian Yee, MD, a member of the Clinical Research Division of Fred Hutchinson Cancer Research Center, showed a long-term, complete remission that has lasted more than 3 years in 1 of the 11 study participants. In 4 other patients with progressive disease, the melanoma temporarily stopped growing.
All the patients in this study had progressive metastatic melanoma that no longer responded to traditional therapy. Prior to the CD8+ T-cell infusions, all patients were treated with high doses of cyclophosphamide to destroy their lymphocytes. Then the CD8+ T cells were removed from the patients and multiplied in the lab before reinfusion.
Of the 11 study patients, 8 received low doses of interleukin-2 (IL-2) growth factor after the T cells were infused. Among these patients, 1 showed a complete remission and 4 experienced a temporary nonprogression of their disease. The remaining 3 patients received higher doses of IL-2, which was determined to be more toxic to the body. Temporary nonprogression of the disease presented in 2 of these patients.
With the exception of the 1 patient who attained a complete remission, all the other patients’ disease eventually progressed within 12 to 19 weeks of T-cell infusion.
According to Yee, the results “confirm that if we can develop methods to grow these kinds of cells in the lab, then we can give these high-proliferating, helper-independent T cells to all patients for T-cell therapy. Fortunately, we have been able to achieve this goal and are in the process of treating patients in an ongoing study with these helper-independent T cells.”