# Venous Thromboembolism in Aggressive B‐Cell Lymphoma Patients Treated with CD19 CAR‐T Therapy: Single‐Institution Study

## TL;DR

This study finds that patients with aggressive B-cell lymphoma treated with CAR-T therapy face a notable risk of venous blood clots, especially in the first month.

## Contribution

The study reports the incidence and risk factors for VTE in LBCL patients undergoing CAR-T therapy, emphasizing PMBCL and ICANS as key factors.

## Key findings

- The 6-month VTE incidence was 7.6%, mostly linked to central venous catheters in the upper extremities.
- PMBCL patients had a 30% VTE incidence, significantly higher than DLBCL and TFL patients.
- High-grade ICANS was strongly associated with VTE occurrence (p = 0.013).

## Abstract

Large B‐cell lymphomas (LBCLs) are a common subtype of non‐Hodgkin lymphomas. CD19 chimeric antigen receptor T‐cell (CAR‐T) therapy has revolutionized LBCL treatment, with high remission rates but also significant toxicities, including cytokine release syndrome (CRS) and immune effector cell‐associated neurotoxicity syndrome (ICANS). Venous thromboembolism (VTE) in CAR‐T therapy patients is understudied.

This study aims to determine the incidence and characteristics of acute VTE in LBCL patients treated with CAR‐T therapy and identify baseline clinical features associated with VTE. Methods: We retrospectively reviewed 172 adult LBCL patients treated with CAR‐T therapy from January 2018 to November 2019 at MD Anderson Cancer Center. Data on demographics, clinical characteristics, and adverse events were collected. VTE events within 6 months post‐CAR‐T therapy were confirmed by diagnostic imaging. Statistical analyses included univariate analyses and cumulative incidence functions.

The cohort was predominantly male (70%), with a median age of 59 years and advanced‐stage disease (76.16%). The 6‐month incidence of VTE was 7.6%, primarily involving upper extremity events related to central venous catheters. Significant associations were found between VTE and disease histology (p = 0.033) and high‐grade ICANS (p = 0.013). PMBCL patients had a higher VTE incidence (30%) compared to DLBCL and TFL. Most VTE events occurred within the first month post‐CAR‐T therapy.

LBCL patients receiving CAR‐T therapy have a significant risk of VTE, particularly within the first month and among those with PMBCL and high‐grade ICANS. This highlights the need to study the role of venous thromboprophylaxis in this context.