High-dose therapy and autologous hematopoietic cell transplantation as front-line consolidation in chronic lymphocytic leukemia: a systematic review

Clinical Practice Recommendations for Use of Allogeneic Hematopoietic Cell Transplantation in Chronic Lymphocytic Leukemia on Behalf of the Guidelines Committee of the American Society for Blood and Marrow Transplantation

We sought to establish clinical practice recommendations to redefine the role of allogeneic hematopoietic cell transplantation (allo-HCT) for patients with chronic lymphocytic leukemia (CLL) in an era of highly active targeted therapies. We performed a systematic review to identify prospective randomized controlled trials comparing allo-HCT against novel therapies for treatment of CLL at various disease stages. In the absence of such data, we invited physicians with expertise in allo-HCT and/or CLL to participate in developing these recommendations. We followed the Grading of Recommendations Assessment, Development and Evaluation methodology. For standard-risk CLL we recommend allo-HCT in the absence of response or if there is evidence of disease progression after B cell receptor (BCR) inhibitors. For high-risk CLL an allo-HCT is recommended after failing 2 lines of therapy and showing an objective response to BCR inhibitors or to a clinical trial. It is also recommended for patients who fail to show an objective response or progress after BCR inhibitors and receive BCL-2 inhibitors, regardless of whether an objective response is achieved. For Richter transformation, we recommend allo-HCT upon demonstration of an objective response to anthracycline-based chemotherapy. A reduced-intensity conditioning regimen is recommended whenever indicated. These recommendations highlight the rapidly changing treatment landscape of CLL. Newer therapies have disrupted prior paradigms, and allo-HCT is now relegated to later stages of relapsed or refractory CLL.

Reappraising the timing of transplant for indolent non-Hodgkin lymphomas

INTRODUCTION

Indolent non-Hodgkin lymphomas (iNHL) remain incurable with standard approaches. The timing of autologous stem cell transplant (ASCT) is changing following the introduction of new drugs that can potentially defer the transplant, improved reduced intensity conditioning (RIC) and haploidentical allogeneic SCT (allo-SCT).

AREAS COVERED

The most relevant aspects concerning the role of hematopoietic stem cell transplantation in the management of iNHL are discussed. Literature search methodology included examination of PubMed index and meeting presentations. Expert commentary: ASCT is not currently employed as consolidation in first-line, being reserved to patients with refractory/relapsed disease. The curative potential of graft-versus-lymphoma (GVL) after RIC allo-SCT could be particularly beneficial in patients with iNHL relapsing after ASCT. This scenario could be modified in the near future by better definition of high-risk patients at diagnosis, by the improvement of minimal residual disease (MRD) evaluation and by the introduction of new drugs in the therapeutic algorithm.

Hematopoietic Cell Transplantation for Richter Syndrome

Treatment combining chemotherapy with immunotherapy as well as novel targeted therapies have shown limited efficacy in Richter syndrome. Overall response rates after chemoimmunotherapy range from 43% to 67%, but remissions are generally short-lived. In chronic lymphocytic leukemia (CLL), allogeneic hematopoietic cell transplantation (all-HCT) is considered a potentially curative treatment modality, yielding 3-year overall survival rates exceeding 50% and a plateau in survival curves. In Richter syndrome, efficacy of allo-HCT depends on demonstrating an objective response (complete remission or partial response) before allografting, with resulting 3-year survival rates of 41% to 75%. On the other hand, the efficacy of autologous HCT is limited, especially when considering that patients autografted for Richter syndrome might relapse with CLL in 35% of cases. Notwithstanding the scarcity of published data, we recommend that patients with Richter syndrome should be referred to transplant centers as soon as the diagnosis is confirmed to evaluate their candidacy for allo-HCT. Establishing a clonal relationship to CLL is important considering the more aggressive disease course in clonally related Richter syndrome. Moreover, achievement of a complete remission or partial response to salvage therapy must be a prerequisite before moving forward with allografting for Richter syndrome. Patients who fail to demonstrate an objective response to salvage therapy should be considered for enrollment in clinical trials.