Prospective study of adoptive activated αβT lymphocyte immunotherapy for refractory cancers: development and validation of a response scoring system

Background aims: This prospective clinical study aimed to determine the efficacy and prognostic factors of adoptive activated αβT lymphocyte immunotherapy for various refractory cancers. The primary endpoint was overall survival (OS), and the secondary endpoint was radiological response. Methods: The authors treated 96 patients. Activated αβT lymphocytes were infused every 2 weeks for a total of six times. Prognostic factors were identified by analyzing clinical and laboratory data obtained before therapy. Results: Median survival time (MST) was 150 days (95% confidence interval, 105–191), and approximately 20% of patients achieved disease control (complete response + partial response + stable disease). According to the multivariate Cox proportional hazards model with Akaike information criterion–best subset selection, sex, concurrent therapy, neutrophil/lymphocyte ratio, albumin, lactate dehydrogenase, CD4:CD8 ratio and T helper (Th)1:Th2 ratio were strong prognostic factors. Using parameter estimates of the Cox analysis, the authors developed a response scoring system. The authors then determined the threshold of the response score between responders and non-responders. This threshold was able to significantly differentiate OS of responders from that of non-responders. MST of responders was longer than that of non-responders (317.5 days versus 74 days). The validity of this response scoring system was then confirmed by internal validation. Conclusions: Adoptive activated αβT lymphocyte immunotherapy has clinical efficacy in certain patients. The authors’ scoring system is the first prognostic model reported for this therapy, and it is useful for selecting patients who might obtain a better prognosis through this modality.