Cytokine-induced killer (CIK) cells in cancer immunotherapy: report of the international registry on CIK cells (IRCC)

Abstract

Purpose: Cytokine-induced killer (CIK) cells represent an exceptional T cell population uniting a T cell and natural killer cell like phenotype in their terminally differentiated CD3+CD56+ subset, which features non-MHC-restricted tumor-killing activity. CIK cells are expandable from peripheral blood mononuclear cells and mature following the addition of certain cytokines. CIK cells have provided encouraging results in initial clinical studies and revealed synergistic antitumor effects when combined with standard therapeutic procedures. Methods: Therefore, we established the international registry on CIK cells in order to collect and evaluate data about clinical trials using CIK cells for the treatment of cancer patients. Moreover, our registry is expected to set new standards on the reporting of results from clinical trials using CIK cells. Clinical responses, overall survival (OS), adverse reactions and immunologic effects were analyzed in 45 studies present in our database. These studies investigated 22 different tumor entities altogether enrolling 2,729 patients. Results: A mean response rate of 39 % and significantly increased OS, accompanied by an improved quality of life, were reported. Interestingly, side effects of CIK cell treatment were minor. Mild fevers, chills, headache and fatigue were, however, seen regularly after CIK cell infusion. Moreover, CIK cells revealed numerous immunologic effects such as changes in T cell subsets, tumor markers, cytokine secretion and HBV viral load. Conclusion: Due to their easy availability and potent antitumor activity, CIK cells emerged as a promising immunotherapy approach in oncology and may gain major importance on the prognosis of cancer.