Impact of Increasing Wait Times on Overall Mortality of Chimeric Antigen Receptor T-Cell Therapy in Large B-Cell Lymphoma: A Discrete Event Simulation Model

Abstract

PURPOSE The development of chimeric antigen receptor (CAR) T cells has transformed oncology treatment, with the potential to cure certain cancers. Although shown to be effective in selected populations and studies, CAR T-cell technology requires considerable health care resources, which may lead to additional wait times to access this type of treatment in future. The objective of our study was to estimate the potential impact of increasing wait times on CAR T-cell therapy effectiveness compared with standard chemotherapy for patients with relapsed/refractory diffuse large B-cell lymphoma. METHODS A health system–level discrete event simulation model was developed to project the potential impact of wait times on CAR T-cell therapy for patients with relapsed/refractory diffuse large B-cell lymphoma. Waiting queues and health states related to treatment and clinical progression were implemented. Using data from the literature, we evaluated nine scenarios of using CAR T-cell therapy with wait times ranging from 1 to 9 months. The outcome of interest was 1-year all-cause mortality. RESULTS Increasing the wait time of receiving CAR T-cell therapy from 1 to 9 months increased the predicted 1-year mortality rate from 36.1% to 76.3%. Baseline 1-year mortality was 34.0% in patients receiving CAR T-cell therapy with no wait times and 75.1% in patients treated with chemotherapy. This resulted in an increased relative mortality rate of 6.2% to 124.5% over a 1- to 9-month wait time compared with no wait time. CONCLUSION We found that modest delays in CAR T-cell therapy significantly hinder its effectiveness. Because CAR T-cell therapy offers a potential cure, it is expected that the uptake rate will be substantially increased once the therapy is regularly funded by a health care system. Wait times may be prolonged if system resource availability does not match the demand. Strategies must be developed to minimize the impact of delays and reduce complications during waiting.