Monoclonal antibodies in conditioning regimens for hematopoietic cell transplantation

The impact of Rituximab administered before transplantation in patients undergoing allogeneic hematopoietic stem cell transplantation: A real-world study

Rituximab is used to eliminate B cells as a chimeric monoclonal antibody directed against CD20, a B-cell antigen expressed on B cells. To explore the impact of rituximab administered before transplantation, we implemented a retrospective, monocentric study and utilized real-world data collected at our center between January 2018 and December 2020, and then followed until December 2021. Based on whether a dose of 375mg/m2 rituximab was used at least once within two weeks before transplantation, patients undergoing allo-HSCT were classified into two groups: rituximab (N=176) and non-rituximab (N=344) group. Amongst all the patients, the application of rituximab decreased EBV reactivation (P<0.01) and rituximab was an independent factor in the prevention of EBV reactivation by both univariate and multivariate analyses (HR 0.56, 95%CI 0.33-0.97, P=0.04). In AML patients, there were significant differences in the cumulative incidence of aGVHD between the two groups (P=0.04). Our data showed that rituximab was association with a decreased incidence of aGVHD in AML patients according to both univariate and multivariate analyses. There was no difference between the two groups in other sets of populations. Thus, our study indicated that rituximab administered before transplantation may help prevent EBV reactivation in all allo-HSCT patients, as well as prevent aGVHD in AML patients after allo-HSCT.

Outcomes of rituximab-BEAM versus BEAM conditioning regimen in patients with diffuse large B cell lymphoma undergoing autologous transplantation

BACKGROUND

Although rituximab-based high-dose therapy is frequently used in diffuse large B cell lymphoma (DLBCL) patients undergoing autologous hematopoietic cell transplantation (auto-HCT), data supporting the benefits are not available. Herein, we report the impact of rituximab-based conditioning on auto-HCT outcomes in patients who have DLBCL.

METHODS

Using the Center for International Blood and Marrow Transplant Research (CIBMTR) registry, 862 adult DLBCL patients undergoing auto-HCT between 2003 and 2017 using BEAM (BCNU, etoposide, cytarabine, melphalan) conditioning regimen were included. All patients received frontline rituximab-containing chemoimmunotherapy and had chemosensitive disease pre-HCT. Early chemoimmunotherapy failure was defined as not achieving complete remission (CR) after frontline chemoimmunotherapy or relapse within 1 year of initial diagnosis. The primary outcome was overall survival (OS).

RESULTS

The study cohort was divided into 2 groups: BEAM (n = 667) and R-BEAM (n = 195). On multivariate analysis, no significant difference was seen in OS (P = .83) or progression-free survival (PFS) (P = .61) across the 2 cohorts. No significant association between the use of rituximab and risk of relapse (P = .15) or nonrelapse mortality (P = .12) was observed. Variables independently associated with lower OS included older age at auto-HCT (P < .001), absence of CR at auto-HCT (P < .001) and early chemoimmunotherapy failure (P < .001). Older age (P < .0002) and non-CR pre-HCT (P < .0001) were also associated with inferior PFS. There was no significant difference in early infectious complications between the 2 cohorts.

CONCLUSION

In this large registry analysis of DLBCL patients undergoing auto-HCT, the addition of rituximab to the BEAM conditioning regimen had no impact on transplantation outcomes. Older age, absence of CR pre auto-HCT, and early chemoimmunotherapy failure were associated with inferior survival.

Autologous hematopoietic cell transplantation: an update for clinicians

High-dose chemotherapy followed by transplantation of autologous hematopoietic progenitor cells has a proven track record of safety and efficacy in hematological malignancies and select solid tumors. The near-universal use of peripheral blood stem cells as source for autografts, routine growth factor support, and antimicrobial prophylaxis post transplantation has improved the safety of this procedure. However, the advent of highly active novel therapies in the last few years warrants reappraisal of the role of autologous transplantation in the therapeutic armamentarium of malignant disorder. This review summarizes the current role of autologous transplantation for hematological malignancies, discusses modern standards for patient selection, and highlights long-term care issues of transplant survivors from an internist's perspective. Role of tumor purging in autologous transplantation, novel transplant conditioning regimens, and post-transplant therapies to prevent disease relapse are reviewed.

Proceedings from the National Cancer Institute's Second International Workshop on the Biology, Prevention, and Treatment of Relapse After Hematopoietic Stem Cell Transplantation: part III. Prevention and treatment of relapse after allogeneic transplantation

In the Second Annual National Cancer Institute's Workshop on the Biology, Prevention, and Treatment of Relapse after Hematopoietic Stem Cell Transplantation, the Scientific/Educational Session on the Prevention and Treatment of Relapse after Allogeneic Transplantation highlighted progress in developing new therapeutic approaches since the first relapse workshop. Recent insights that might provide a basis for the development of novel, practical clinical trials were emphasized, including utilization of newer agents, optimization of donor lymphocyte infusion (DLI), and investigation of novel cellular therapies. Dr. de Lima discussed pre-emptive and maintenance strategies to prevent relapse after transplantation, for example, recent promising results suggestive of enhanced graft-versus-tumor activity with hypomethylating agents. Dr. Schmid provided an overview of adjunctive strategies to improve cell therapy for relapse, including cytoreduction before DLI, combination of targeted agents with DLI, and considerations in use of second transplantations. Dr. Porter addressed strategies to enhance T cell function, including ex vivo activated T cells and T cell engineering, and immunomodulatory approaches to enhance T cell function in vivo, including exogenous cytokines and modulation of costimulatory pathways.