Drug containing diptheria toxin discovered to be effective in killing melanoma cells

Louisville, Ky. - Researchers at the University of Louisville’s James Graham Brown Cancer Center say they have discovered that a drug containing parts of the diphtheria toxin appears to prompt the immune system to recognize and kill cancer cells in patients with advanced skin cancer.

In research with mice, the research team discovered that the drug denileukin diftitox targets and depletes regulatory T-cells, allowing T-cells in the immune system known as CD8 + T lymphocytes to attack and kill melanoma cells. This success led to testing of the drug in human patients.

The researchers gave seven patients with stage IV melanoma nine or 12 micrograms of the drug per kilogram of body weight daily for four days, every three weeks for four cycles. Five patients who received the higher dose experienced significant regression of several metastatic tumors.

All of the patients are still alive after 12 months, according to the study, and a phase 2 trial is continuing to examine the effectiveness of the drug.