Favorable survival after allogeneic stem cell transplantation with reduced-intensity conditioning regimens for relapsed/refractory follicular lymphoma

Allogeneic Stem Cell Transplantation and Chimeric Antigen Receptor (CAR) T-Cell Therapy for the Treatment of Non-Hodgkin Lymphoma

Despite the myriad of available treatments, a substantial subset of patients with non-Hodgkin lymphoma are not able to achieve a prolonged disease-free interval with conventional chemotherapy or targeted agents. For these patients, hematopoietic stem cell transplantation remains an option for consolidative or curative treatment. Additionally, chimeric antigen receptor T-cell therapy has emerged for patients with relapsed/refractory B-cell lymphomas. Published studies vary widely in their selected approach to transplant and cellular therapies. This review summarizes available data related to allogeneic hematopoietic stem cell transplantation and chimeric antigen receptor T-cell therapy for the treatment of non-Hodgkin lymphomas.

Allogeneic Stem Cell Transplantation for Patients with Natural Killer/T Cell Lymphoid Malignancy: A Multicenter Analysis Comparing Upfront and Salvage Transplantation

Natural killer (NK)/T cell lymphoid malignancy comprises extranodal NK/T cell lymphoma (ENKTL) and aggressive NK cell leukemia (ANKL), and the outcomes for advanced or relapsed/refractory ENKTL and ANKL remain poor. Allogeneic stem cell transplantation (SCT) can be used as a frontline consolidation treatment to prevent the relapse of advanced disease or as salvage treatment after chemotherapy for relapsed sensitive disease. We retrospectively analyzed 36 patients (ENKTL, n = 26; ANKL, n = 10) who underwent upfront (n = 19) and salvage allogeneic SCT (n = 17) at 6 hospitals. Patients received myeloablative (n = 25) or reduced-intensity (n =11) conditioning regimens depending on the institute's policy. The median age at the time of allogeneic SCT was 37 years (range, 17 to 62), and more patients with ANKL (8/10) received upfront allogeneic SCT than ENKTL patients (11/26). Disease status before allogeneic SCT, conditioning regimen, and donor source did not differ between upfront and salvage allogeneic SCT groups. Febrile neutropenia (n = 20) and acute graft-versus-host disease (n = 16) were common adverse events. The median overall survival (OS) and progression-free survival (PFS) after allogeneic SCT were 11.8 months and 10.0 months, respectively. Twelve patients died from disease relapse and 12 from nondisease-related causes. Ten deaths occurred within 100 days after allogeneic SCT (10/24); these were mostly related to disease relapse (n = 8). The OS after allogeneic SCT did not differ between ENKTL and ANKL (P = .550) or between upfront and salvage SCT (P = .862). Complete chimerism was significantly associated with better PFS (P < .001). No significant differences in PFS were observed based on the conditioning regimen or source of stem cells (P > .05). Allogeneic SCT may be beneficial for patients with ENKTL and ANKL given that some patients were able to maintain their remission after allogeneic SCT. However, allogeneic SCT should only be performed in highly selected patients because the risks of disease relapse and nondisease-related mortality remain high.

Efficacy of Idelalisib as Bridge to Allogeneic Stem Cell Transplant in Relapsed Follicular Lymphoma: A Case Report

Purpose

A large number of new therapeutic agents have been studied for patients with relapsed/refractory follicular lymphoma (FL). Among new therapies, idelalisib, a novel PI3K inhibitor, shows promising results in the management of this disease.

Case report

We describe the case of a 39-year-old patient with a diagnosis of grade 3a FL and a Follicular Lymphoma International Prognostic Index score of 2, who underwent several lines of therapy (including autologous stem cell transplant) with transient responses or no response at all. The patient was subsequently treated with 5 courses of idelalisib monotherapy, achieving a partial response. No relevant toxicities occurred. The patient underwent allogeneic stem cell transplant (allo-SCT) from an unrelated donor and obtained a complete response, which was confirmed after 3, 6, 9, and 12 months, and is still ongoing.

Conclusions

As previously reported, the achievement of a good response is predictive for a better outcome after allo-SCT: idelalisib represents an effective treatment option for patients with relapsed/refractory FL, which can also be adopted as a bridge to allo-SCT.

The role of stem cell transplantation in follicular lymphoma

With the introduction of novel treatments paradigms to if or when to use transplantation strategies for patients with follicular lymphoma have changed substantially. Autologous transplantation has been intensively evaluated as consolidation after first induction treatment with positive effects, however the introduction of Rituximab led to comparable improvements and HDT has been moved to relapse treatment. In this indication HDT was frequently use already at first relapse, but now is dominantly used in patients with a highrisk profile, e.g. failure of response, early or multiply relapse and/or signs of transformation. The ideal place for allogeneic transplantation is even harder to define, as the curative potential might be outweighed by the substantial side effect profile and the indication must always be discussed in the light of available alternatives. In consequence, transplantation strategies remain an important therapeutic instrument for patients with FL, however timing within the treatment course has to be defined individually.

Hematopoietic cell transplantation for diffuse large B-cell and follicular lymphoma: Current controversies and advances

Non-Hodgkin's lymphoma (NHL) constitutes a collection of lymphoproliferative disorders with diverse biologic, histologic, and clinical features. With a better understanding of the molecular pathogenesis, recently there have been major advances in the treatment of NHLs including addition of novel monoclonal antibodies, targeted therapies, and immune activators to the therapy armamentarium. Despite these remarkable developments, autologous hematopoietic cell transplantation (auto-HCT) remains not only a standard-of-care curative option for aggressive NHL but also an important therapeutic option for indolent NHL. In NHL, for patients with high-risk features, including those heavily pretreated or with refractory disease or those experiencing failure after an auto-HCT, allogeneic HCT (allo-HCT) remains the only curative option. In this review, we briefly discuss the role of transplantation in diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL). In DLBCL patients, we discuss the role of HCT in clinically and biologically defined ultra-high-risk disease. In FL patients, auto-HCT is best reserved for relapsed chemosensitive patients after two to three lines of prior chemoimmunotherapies, who are not candidates for allo-HCT, either because of donor unavailability, associated comorbidities, or patient preference. Reduced-intensity conditioning allo-HCT offers the curative option for patients with relapsed/refractory FL. Although the emergence of targeted, biologic, and immunological therapies is welcoming, it is currently unclear how these new therapies might enhance or replace allo-HCT. Until we have further definitive data, allo-HCT remains the only curative option.

Allogeneic Hematopoietic Cell Transplantation as Curative Therapy for Patients with Non-Hodgkin Lymphoma: Increasingly Successful Application to Older Patients

Non-Hodgkin lymphoma (NHL) constitutes a collection of lymphoproliferative disorders with widely varying biological, histological, and clinical features. For the B cell NHLs, great progress has been made due to the addition of monoclonal antibodies and, more recently, other novel agents including B cell receptor signaling inhibitors, immunomodulatory agents, and proteasome inhibitors. Autologous hematopoietic cell transplantation (auto-HCT) offers the promise of cure or prolonged remission in some NHL patients. For some patients, however, auto-HCT may never be a viable option, whereas in others, the disease may progress despite auto-HCT. In those settings, allogeneic HCT (allo-HCT) offers the potential for cure. Over the past 10 to 15 years, considerable progress has been made in the implementation of allo-HCT, such that this approach now is a highly effective therapy for patients up to (and even beyond) age 75 years. Recent advances in conventional lymphoma therapy, peritransplantation supportive care, patient selection, and donor selection (including the use of alternative hematopoietic cell donors), has allowed broader application of allo-HCT to patients with NHL. As a result, an ever-increasing number of NHL patients over age 60 to 65 years stand to benefit from allo-HCT. In this review, we present data in support of the use of allo-HCT for patients with diffuse large B cell lymphoma, follicular lymphoma, and mantle cell lymphoma. These histologies account for a large majority of allo-HCTs performed for patients over age 60 in the United States. Where possible, we highlight available data in older patients. This body of literature strongly supports the concept that allo-HCT should be offered to fit patients well beyond age 65 and, accordingly, that this treatment should be covered by their insurance carriers.