Economic Burden of Neurologic Toxicities Associated with Treatment of Patients with Relapsed or Refractory Diffuse Large B-Cell Lymphoma in the United States.

Abstract

Background: Chimeric antigen receptor (CAR) T-cell therapy, which is approved for the treatment of relapsed or refractory diffuse large B-cell lymphoma (DLBCL), can be associated with potentially severe and costly neurologic adverse events (AEs).

Objectives: To develop an evidence-based list of treatment-related neurologic AEs in patients with relapsed or refractory DLBCL, including AEs related to CAR T-cell therapies, and to estimate the healthcare costs associated with these neurologic AEs in a real-world setting.

Methods: We identified grade ≥3 neurologic AEs that occurred in ≥2% of patients by reviewing drug prescribing information and published clinical trials with therapies used for relapsed or refractory DLBCL. Data from 3 nationally representative claims databases were used to identify adults with relapsed or refractory DLBCL, who were eligible for the study if they received 1 of 4 types of therapy, including CAR T-cell therapy, high-intensity cytotoxic therapy, low-intensity cytotoxic therapy, or targeted therapies. The rates of neurologic AEs and total healthcare costs were calculated for patients with and without neurologic AEs within 30 days of treatment. The costs were inflated to 2019 first-quarter US dollars.

Results: A total of 16 types of neurologic AEs were identified, including 13 events related to CAR T-cell therapy and 5 related to conventional immunochemotherapy regimens, with 2 overlapping event types. Of these AEs, 11 were included in the claims analysis, based on available diagnosis codes. Of the 11,098 adults with relapsed or refractory DLBCL in the study, 118 patients received CAR T-cell therapy, 9483 received a high-intensity cytotoxic therapy, 1259 received a low-intensity cytotoxic therapy, and 238 received a targeted therapy. A total of 299 (2.7%) patients had ≥1 neurologic AEs during the 30-day postindex period. Of these patients, 43 received CAR T-cell therapy (36.4% of the 118 CAR T-cell therapy users). The mean total healthcare cost was $71,982 higher for patients with neurologic AEs than for patients without neurologic AEs. The trend of higher costs in patients with neurologic AEs was consistent across the treatment groups and was most pronounced in CAR T-cell therapy users ($143,309; 95% confidence interval, $5838-$280,779).

Conclusion: Patients with relapsed or refractory DLBCL who had severe or life-threatening neurologic AEs incur substantially higher costs than their counterparts who do not have neurologic AEs, with the largest cost difference in patients who receive CAR T-cell therapy.