T Cell Cloning as Potential Cancer Treatment

By cloning a man’s own T cells, researchers were able to drive off his late stage melanoma without any other therapies.
From the Fred Hutchinson Cancer Research Center:

Yee [Cassian Yee, M.D., an associate member of the Clinical Research Division at Fred Hutchinson Cancer Research Center –ed.] and colleagues removed CD4+ T cells, a type of white blood cell, from a 52-year-old man whose Stage 4 melanoma had spread to a groin lymph node and to a lung. T cells specific to targeting the melanoma were then expanded vastly in the laboratory using modifications to existing methods. The lab-grown cells were then infused into the patient with no additional pre- or post-conditioning therapies, such as growth-factor or cytokine treatment. Two months later, PET and CT scans revealed no tumors. The patient remained disease free two years later, when he was last checked.
The patient in the journal report was one of nine patients with metastatic melanoma who were being treated in a recently completed clinical trial to test dose- escalation of autologous CD4+ T cells. Earlier studies performed by Yee used CD8+ T cells, which do not persist in the body without the support of CD4+ T cells or growth factors such as interleukin 2. Yee and colleagues theorized that infusion of a massive dose of CD4+ T cells would persist longer in the body because they make their own growth factor, interleukin 2, while stimulating the anti-tumor effect of the patient’s existing CD8+ T cells. However, until recently there was no feasible way to isolate and expand anti-tumor CD4+ T cells in the lab.
The researchers were successful in all of these areas. The patient received a dose of 5 billion cloned CD4+ T cells with specificity for the melanoma-associated NY-ESO-1 antigen. The cells persisted for at least 80 days in the patient’s body. And, even though only 50 percent to 75 percent of the patient’s tumor cells expressed the NY-ESO-1 antigen, the entire tumor regressed following the infusion. The scientists postulated that the patient’s immune response was broadened to other antigens expressed by the tumor cells. Follow-up tests showed T-cell responses to two additional tumor antigens, MAGE-3 and MART-1.

Fred Hutchinson Cancer Research Center press release: Patient’s own infection-fighting T cells put late-stage melanoma into long-term remission – without chemotherapy or radiation …
Image: Human melanoma cell undergoing cell division. (Wellcome Images)