Ofatumumab as Part of Reduced Intensity Conditioning (RIC) Regimen for Patients With High Risk Chronic Lymphocytic Leukemia (CLL) Undergoing Allogeneic Hematopoietic Cell Transplantation

• Status: Unknown status
• Trial end date: 2017-10-01

Summary

A good proportion of patients with chronic lymphocytic leukemia (CLL) can be managed effectively with palliative chemotherapy. However, there is a group of younger patients with poor risk disease whose life expectancy is significantly reduced. As a result, reduced intensity conditioning (RIC) allogeneic hematopoietic cell transplantation (allo-HCT) has been investigated as a potentially curative procedure.

Recently, the European Group for Blood and Marrow Transplantation (EBMT) published a set of guidelines suggesting situations where allo-HCT might be considered a therapeutic option for CLL patients. Their conclusions were that allo-HCT was reasonable for younger CLL patients refractory to fludarabine, relapsing within two years of intensive treatment, or with p53 abnormalities requiring treatment.

However, the results with RIC allo-HCT are not entirely satisfactory, and progression-free survival after allo-HCT revolves around 35-40% at 3-5 years following allo-HCT. This is due to non-relapse mortality, which is significantly associated with the development of graft-versus-host disease (GVHD), but also due to disease relapse. These relapses may occur early in the course of the transplantation, like any other hematological malignancy, but late relapses have also been reported.

Several strategies have been tested in order to improve these results. The anti-CD20 monoclonal antibody rituximab, given concomitantly with allo-HCT or donor lymphocyte infusions, may reduce graft-versus-host disease and facilitate disease control. This may be due, not only to direct cytotoxicity, but also to modulation of GVHD and the graft-versus CLL effect (GVCLL). Interestingly, rituximab has been shown to promote the cross-presentation of tumor-derived peptides by antigen-presenting cells, thus enhancing the formation of cytotoxic T-cell clones and a GVCLL effect. With the addition of rituximab to the conditioning regimen, rates at 4 years for current progression-free survival (CPFS) and overall survival were 44% and 48%.

The investigators hypothesize that ofatumumab, having a more potent anti-CLL activity and complement-dependent cytoxicity than rituximab, could improve disease control and modulate the GVCLL effect more effectively, thus reducing the GVHD rate and subsequently improving the non-relapse mortality and progression-free survival in the long term.

• Phase: Phase 2

Details

• Lead Sponsor: Grupo Espanol de trasplantes hematopoyeticos y terapia celular
• Collaborator: GlaxoSmithKline
• Treatments: Antibodies, Monoclonal; Ofatumumab