Changing Trends in B-Cell Non-Hodgkin Lymphoma Treatment: The Role of Novel Monoclonal Antibodies in Clinical Practice

We are currently witnessing a dramatic shift in our approach to the treatment of B-cell non-Hodgkin lymphoma (B-NHL). In the evolving clinical landscape, novel treatments for this clinically heterogeneous disease span a wide range of interventions, encompassing targeted agents, cell therapy approaches, and novel monoclonal antibodies (NMABs). Among these, the latter are likely to exert the most profound impact due to their distinctive high efficacy and versatile applicability. NMABs represent a heterogeneous group of agents, including naked antibodies, immunotoxins, and T-cell-engaging molecules. In recent times, several NMABs have either gained regulatory approval or are on the verge of introduction into clinical practice, addressing multiple therapeutic indications and treatment regimens. Their anticipated impact is expected to be broad, initially in the context of relapsed/refractory (R/R) disease and subsequently extending to early treatment lines. The scope of this review is to provide a comprehensive overview of the biological characteristics, clinical properties, efficacy, and toxicity profiles of NMABs that have recently been introduced or are nearing integration into clinical practice.

Hematopoietic Stem Cells (HSC) and Granulocyte Macrophage Progenitors (GMP) are the Oxidative Stress Targets in Low/Intermediate-1 Risk Myelodysplastic Syndromes

Introduction

Myelodysplastic Syndromes (MDS) are a heterogenous group of clonal hematopoietic stem cell malignancies. Previous studies showed that Reactive Oxygen Species (ROS) play a role in the pathogenesis and clinical evolution of MDS, contributing to Hematopoietic Stem and Progenitor Cells (HSPC) genetic instability. Less is known about ROS levels in the various sub-populations of MDS HSPC and how they correlate with clinical data in MDS patients. Our study aims to analyze ROS levels in MDS Hematopoietic Stem Cells (HSC), common myeloid progenitors (CMP), Granulocyte Macrophages Progenitors (GMP) and megakaryocyte-erythrocyte progenitors (MEP); afterwards, we looked at the relationship between ROS levels and clinical data.

Methods

thirty-eight MDS and 27 Normal Bone Marrow (NBM) samples were collected; ROS levels were analyzed via multicolor flow cytometry.

Results

In both NBM and MDS, HSC showed much higher ROS levels than progenitors (3 to 4 folds, p < 0.0001); HSC ROS were significantly more elevated in MDS-no excess blasts versus MDS with excess blasts and versus NBM. GMP from MDS-no excess blasts showed higher ROS compared to NBM GMP. The 3 MDS with Ringed Sideroblasts (RS) showed more elevated ROS in HSC and GMP compared to the not RS low/intermediate-1 MDS; the 2 monosomy 7 patients displayed higher ROS levels in each subpopulation compared to the normal karyotype MDS; the only del(5q) patient did not show relevant differences in ROS levels compared to the median of the normal karyotype MDS ROS. The 9 high transfusion burden patients exhibited higher ROS in HSC and GMP compared to NBM HSC and GMP. These data were not confirmed in low transfusion burden (n:2) and non-transfused patients (n:26). In low/intermediate-1 MDS, a direct correlation between ferritin values and ROS levels in progenitors, but not in HSC, was detected. Interestingly, low/intermediate-1 risk patients that are no longer responding to recombinant human erythropoietin (rh-EPO) showed higher ROS levels in GMP and HSC.

Conclusions

Our data showed that ROS can play a role in the pathogenesis and maintenance of low and intermediate-1 risk MDS clone; ROS status can be influenced by several clinical factors as ferritin levels and rh-EPO treatment. In this scenario, high ROS levels can contribute to genetic instability and influence progression to AML. Further biological studies are needed to elucidate ROS role in MDS pathogenesis and analyze the possible benefit of antioxidant drugs added to the standard MDS treatments.

Epstein-Barr virus reactivation in allogeneic stem cell transplantation is highly related to cytomegalovirus reactivation

Monitoring of Epstein-Barr virus (EBV) load and pre-emptive rituximab is an appropriate approach to prevent post-transplant lymphoproliferative disease (PTLD) occurring after hematopoietic stem cell transplantation (HSCT). This pre-emptive approach, based on EBV-DNA monitoring through a quantitative polymerase chain reaction, was applied to 101 consecutive patients who underwent allo HSCT at our Institute (median age 50). A single infusion of rituximab was administered to 11 of 16 patients who were at high risk for progression to PTLD, defined as a DNA value >10 000 copies/mL. All patients cleared EBV DNAemia, without any recurrences. Main factors significantly associated with high risk for PTLD were as follows: (i) unrelated vs. sibling (26% vs. 7%; p = 0.011); (ii) T-cell depletion (29% vs. 6%; p = 0.001); (iii) graft versus host disease (GVHD; 30% vs. 7%; p = 0.002); and (iv) cytomegalovirus (CMV) reactivation (29% vs. 4%; p = 0.001). Multivariate analysis showed that CMV reactivation was the only independent variable associated with EBV reactivation. We conclude that: (i) a single infusion of rituximab is able to prevent the risk of progression into EBV-related PTLD; and (ii) CMV reactivation is strongly associated with EBV reactivation; therefore, an intensive EBV monitoring strategy could be advisable only in case of CMV reactivation.