Differences in lymphoma patients between chimeric antigen receptor T-cell therapy trials and the general population

Chimeric antigen receptor (CAR)-T cell therapies appear to be promising treatments for non-Hodgkin's and B-cell lymphoma. However, several CAR-T therapies approved by the US Food and Drug Administration have only been tested for efficacy in relatively few single-arm clinical trials with small sample sizes. We sought to examine the differences between patients in these trials and the general population of patients with non-Hodgkin's and B-cell lymphoma. Five hundred and twenty-two patients from 15 CAR-T trials found in a systematic review and 417,492 patients from the Surveillance, Epidemiology, and End Results (SEER) Program database were compared. CAR-T study participants appeared to be younger (46.7% under 70 years old vs. 42.2%), more male (68.0% vs. 55.7%), and followed for a shorter period of time compared to patients in the SEER population (mean [M] 45.6 months, 95% confidence interval [CI] 17.7 to 63.3 months follow-up vs. M 57.1 months, 95% CI 57.0 to 57.3 months survival). CAR-T study participants may differ significantly from the general population of patients with non-Hodgkin's and B-cell lymphoma. Effectiveness of CAR-T therapies in the general population of lymphoma patients may differ from effectiveness demonstrated in trials. Newly created CAR-T patient registries are essential to establishing population-level effectiveness of the therapies.