SP18 | CORRELATION BETWEEN EPCORITAMAB AND D-DIMER INCREASE IN PATIENTS WITH RELAPSED/REFRACTORY B-CELL LYMPHOMA

Background: Epcoritamab, an anti-CD3/CD20 bispecific antibody, is employed as a third-line or subsequent therapy for patients with relapsed/refractory (R/R) B-cell lymphoma. Cytokine release syndrome (CRS) is a common adverse event associated with this treatment. CRS results from the release of pro-inflammatory cytokines by activated T lymphocytes, macrophages, and endothelial cells. This pilot study aimed at exploring a potential role of D-dimer as early biomarker of CRS onset in patients treated with Epcoritamab. Methods: An observational study was conducted at our center including 13 patients with R/R B-cell lymphoma, 10 of whom were diagnosed with Diffuse Large B Cell Lymphoma (DLBCL), treated with Epcoritamab between May 2023 and December 2024. D-dimer levels were measured at baseline, before the first dose, before the full dose, and 24 hours after the full dose. Five CRS events and no immune effector cell-associated neurotoxicity syndrome (ICANS) were observed. Patients were divided into two groups based on the occurrence (Group A) or absence (Group B) of CRS. Statistical analysis was performed using the Mann-Whitney test, with a significance threshold set at p < 0.05. Results: Five patients developed CRS, four of which were grade 1 and one was grade 3. We observed no significant differences in D-dimer levels, at the various time points, in group A vs group B. However, descriptive analysis showed a progressive increase in median D-dimer levels in patients developing CRS compared to those who did not: a modest divergence was noted prior to the first dose, which became more evident before full-dose administration, when the median D-dimer level was 959 ng/mL in the CRS-negative group and 1847 ng/mL in the CRS-positive group, corresponding to a 92.7% increase. After 24 hours, the difference increased further: 2455 ng/mL in Group A versus 821 ng/mL in Group B, representing a 199% increase. Conclusions: Although these data did not reach statistical significance, they highlight a marked growth pattern in D-dimer levels in patients who developed CRS, raising the hypothesis that D-dimer could serve as a dynamic marker to monitor. Larger prospective studies could clarify whether this increase has early predictive value, potentially improving CRS risk management in patients treated with Epcoritamab.