Modified dendritic cells that can recognize cancer-made protein fragments have shown promise in a small clinical trial studying melanoma. Duke University’s Scott Pruitt, M.D., Ph.D., also of Merck Research Laboratories, led a team of investigators using these modified immune cells to selectively seek an destroy cancer via vaccination.
Dr. Pruitt and his colleagues today report in the Journal of Clinical Investigation on their trial evaluating melanoma patient response to modified dendritic cell vaccination.
For this small investigation, the researchers studied 12 patients total—four who were vaccinated with regular dendritic cells, three who underwent control treatment, and five who received dendritic cells that were modified to recognize tumor antigens associated with constitutive proteasomes.
They found that vaccination with all types of dendritic cells elicited an immune response that peaked after three to four courses, though patients who received the modified dendritic cells showed a longer-lasting immune response, plus fewer circulating melanoma cells. One patient under investigation who had active disease showed partial clinical response to this modified dendritic cell vaccine treatment, while another with active disease administered the same showed a complete clinical response, the researchers report.
Overall, the team’s results suggest modifying dendritic cells such that they recognize constitutive proteasome-produced tumor antigens enhances immune recognition of melanoma cells.
"Melanoma immunotherapy using mature DCs expressing the constitutive proteasome" was published Jun 24 in the Journal of Clinical Investigation.