Impact of rituximab on treatment outcomes of patients with angioimmunoblastic T-cell lymphoma; a population-based analysis

Background: Patients with angioimmunoblastic T-cell lymphoma (AITL) are treated with cyclophosphamide, doxorubicin, vincristine and prednisone with or without etoposide (CHO(E)P). In the majority of cases, Epstein-Barr virus (EBV)-positive B-cells are present in the tumour. There is paucity of research examining the effect of rituximab when added to CHO(E)P. In this nationwide, population-based study, we analysed the impact of rituximab on overall response rate (ORR), progression-free survival (PFS) and overall survival (OS) of patients with AITL. Methods: Patients with AITL diagnosed between 2014 and 2020 treated with >one cycle of CHO(E)P with or without rituximab were identified in the Netherlands Cancer Registry. Sur-vival follow-up was up to 1st February 2022. Baseline characteristics, best response during first-line treatment and survival were collected. PFS was defined as the time from diagnosis to relapse or to all-cause-death. OS was defined as the time from diagnosis to all-cause-death. Multivariable analysis for the risk of mortality was performed using Cox regression. Findings: Out of 335 patients, 146 patients (44%) received R-CHO(E)P. Rituximab was more frequently used in patients with a B-cell infiltrate (71% versus 89%, p < 0.01). The proportion of patients who received autologous stem cell transplantation (ASCT) was similar between CHO(E)P and R-CHO(E)P (27% versus 30%, respectively). The ORR and 2-year PFS for pa-tients who received CHO(E)P and R-CHO(E)P were 71% and 78% (p = 0.01), and 40% and 45% (p = 0.12), respectively. The 5-year OS was 47% and 40% (p = 0.99), respectively. In multi -variable analysis, IPI-score 3-5, no B-cell infiltrate and no ASCT were independent prognostic factors for risk of mortality, whereas the use of rituximab was not. Interpretation: Although the addition of rituximab to CHO(E)P improved ORR for patients with AITL, the PFS and OS did not improve. 2022 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).